Abstract: Cardiac resynchronization therapy (CRT) is an emerging option for treating dyssynchrony-associated heart failure in patients with pediatric or congenital heart disease. CRT has proved beneficial for both the acute manipulation of cardiac output after surgery for congenital heart defects and for the management of chronic systemic ventricular failure. Although there are no prospective and randomized trial data, retrospective series show that CRT is similarly effective for managing dyssynchrony-associated heart failure in this younger population as it is for treating adults with ischemic and idiopathic dilated cardiomyopathy. The heterogeneity of anatomical and functional substrates in which CRT shows efficacy calls for further studies defining the usefulness of CRT in specific subgroups of patients.
Abstract: Objectives: To evaluate the impact of moderate versus deep perioperative hypothermia on postoperative morbidity in patients receiving the arterial switch operation (ASO). Methods: One hundred consecutive patients received the ASO from 9/98 to 4/06 using temperature-corrected full-flow moderate (M>24 degrees C, n=51) or deep hypothermic cardiopulmonary bypass (CPB) (D <20 degrees C, n=49). Complex TGA morphology was present in 33 patients (M: 27.4%, D: 38.8%, n.s.). Median age was 9 days (M) versus 10 days (D) and body weight was 3.5+/-0.7kg (M) versus 3.6+/-0.9kg (D) (both p=n.s.). Follow-up was 3.7+/-2.1 years. Results: Lowest perioperative rectal temperature was 25.3+/-1.1 degrees C (M) versus 19.0+/-0.8 degrees C (D), p<0.001. Intraoperative blood transfusion (M: 231+/-47ml, D: 252+/-112ml, p=0.04) and postoperative lactate level (M: 3.2+/-1.3mmol/l, D: 3.8+/-2.4mmol/l, p=0.02) were lower under moderate hypothermia. One patient (D) suffered myocardial ischemia, required ECMO support and died. All other patients were safely weaned from CPB using dopamine (M: 3.0mug/kgmin, D: 3.4mug/kgmin, n.s.) and dobutamine (M: 5.6mug/kgmin, D: 6.7mug/kgmin, p=0.048). Secondary chest closure was performed in 41% (M) versus 59% (D) (p=0.04). Patients were extubated after 89h (M) versus 126h (D) (p=0.03). Under moderate hypothermia ICU stay (M: 8.4+/-4.7 days, D: 12.0+/-13.8 days, p=0.03) and hospital stay (M: 12.8+/-6.8 days, D: 20.7+/-15.5 days, p=0.001) were shorter. Five-year freedom from reoperation was 97.0% for simple and 85.2% for complex TGA with RVOT reconstruction in 4/6 patients. Conclusions: The ASO under full-flow moderate compared to deep hypothermia was advantageous regarding length of procedure and primary chest closure rate. Moderate hypothermia seemed to be beneficial for pulmonary recovery, length of chest tube drainage treatment and inotropic support. No worse early or long-term effects of moderate hypothermia were found.
Abstract: AIMS: Wolff-Parkinson-White syndrome with right septal or posteroseptal accessory pathways causes eccentric septal mechanical activation and may provoke left ventricular (LV) dyssynchrony and dysfunction. The aim of the study was to evaluate the effect of radiofrequency catheter ablation (RFA) of the accessory pathways on LV function. METHODS AND RESULTS: Retrospectively, transthoracic echocardiography and electrocardiogram recordings were analysed in 34 patients (age: 14.2 +/- 2.5 years) with right septal or posteroseptal accessory pathways prior and after (median: 1 day) successful RFA. Results prior to RFA, LV ejection fraction was decreased (<55%) in 19/34 patients (56%). After RFA, QRS duration was normalized (129 +/- 23 vs. 90 +/- 11, P < 0.0001), LV function improved (ejection fraction: 50 +/- 10 vs. 56 +/- 4%, P = 0.0005) and septal-to-posterior wall motion delay as a global measure for LV dyssynchrony decreased (110 +/- 94 vs. 66 +/- 53, P = 0.012). Longitudinal two-dimensional strain evaluated in five patients demonstrated a decrease of left intraventricular mechanical delay from 292 +/- 125 to 118 +/- 37 ms after RFA. CONCLUSION: Wolff-Parkinson-White syndrome with right septal or posteroseptal accessory pathways may cause LV dyssynchrony and jeopardize global LV function. Radiofrequency catheter ablation resulted in normalized QRS duration, mechanical resynchronization, and improved LV function. Even in the absence of arrhythmias, RFA of right septal or posteroseptal pathways may be considered in patients with significantly decreased LV function.
Abstract: We are describing a most unusual variant of aortic arch interruption. The ascending aorta was atretic above the sinutubular junction forming a blind-ending pouch. The coronary arteries were the only vessels arising from the aortic trunk. All the brachiocephalic vessels were perfused in retrograde fashion through the arterial duct. The aortic valve itself was dysplastic, stenotic, and permitted severe regurgitation. There was no subaortic obstruction. A modified first stage Norwood palliation was performed. Due to myocardial insufficiency transthoracic extracorporeal membrane oxygenation had to be commenced at the end of surgery. Unfortunately the child died due to severe intracranial hemorrhage.
Abstract: We report an adolescent with giant cell myocarditis (GCM) mimicking tachycardia-induced cardiomyopathy. His electrocardiogram (ECG) was typical for an incessant form of fascicular ventricular tachycardia. The patient rapidly deteriorated and required support using extracorporeal membrane oxygenation (ECMO). Biopsy revealed GCM with massive myocyte necrosis. He was successfully heart transplanted 6 days after admission.
Abstract: Transoesophageal echocardiography (TOE) requires extensive hands-on training, and it is for this purpose we have designed EchoComTEE, a simulator for TOE. It consists of a manikin and dummy probe; according to the position of the dummy probe (tracked by an electromagnetic sensor), two-dimensional (2D) images are calculated from three-dimensional (3D) data sets. Echocardiographic images are presented side-by-side with a virtual scene consisting of a 3D heart, probe tip and image plane. In this way the trainee is provided with visual feed-back of the relationship between echocardiogram and image plane position. We evaluated the simulator using a standardised questionnaire. Twenty-five experts and 31 novice users participated in the study. Most experts graded the simulator as realistic and all recommended its use for training. Most novice users felt the simulator supported spatial orientation during TOE and, as anaesthetists often do not have training in transthoracic echocardiography, in this group the TOE simulator might be particularly useful.
Abstract: In a 7-year-old boy with normal hearing suffering from repeated syncope an extremely prolonged QTc interval (up to 700 ms) was found. The mother was completely asymptomatic and the father had an intermittently borderline QTc interval (maximum 470 ms) but no symptoms. In the proband a mutation analysis of KCNQ1 gene revealed a homozygous 1893insC mutation. The parents were heterozygous for this mutation. There was no consanguineous marriage in the family. The clinical relevance of these findings is that apparently normal individuals may have a latent reduction of repolarizing currents, a "reduced repolarization reserve," because they are carriers of latent ion channel genes mutations.
Abstract: BACKGROUND: The bovine jugular vein conduit (Contegra [Medtronic, Inc, Minneapolis, MN]) is one option for right ventricular outflow tract reconstruction. We examined the effect of patient age, conduit size, hemodynamics, and cardiac malformation on early and mid-term outcome. METHODS: Seventy-eight bovine jugular vein implantations were performed over 5 years. Follow-up averaged 31 +/- 17 months. Risk factor and adverse event analyses for graft dysfunction were performed by multivariate logistic regression and Kaplan-Meier analysis. RESULTS: There was no early mortality. Two late deaths occurred after 9 and 15 months. Early postoperative echocardiography revealed bovine jugular vein regurgitation greater than 2+ in 10 patients, all of which had conduit dilatation, had received a 12-mm conduit, and had a right-ventricular-to-left ventricular pressure ratio greater than 0.6. Two additional patients had severe conduit incompetence develop at the 2-year follow-up. During follow-up, mean gradients increased from 15 to 23 mm Hg (p = 0.03) and stenosis at the distal anastomosis occurred in 25% of patients. Percutaneous interventions were performed in 19 patients (24.4%). Conduit exchange was required in 10 patients (12.8%) after a mean of 14.9 months for severe graft incompetence (8 patients) and progressive supravalvular stenosis (2 patients). Freedom from reoperation was 77.6% and 59.3% at 1 and 4 years for patients less than 1 year of age compared with 93.5% and 87.4% for patients older than 1 year of age (p < 0.001). Risk factors for reoperation were age less than 1 year, correction of truncus arteriosus, conduit size of 12 mm, and persistently elevated right-ventricular-to-left ventricular pressure ratio greater than 0.6 (p = 0.001 each). CONCLUSIONS: Bovine jugular vein implantation is associated with low reoperation and acceptable reintervention rate in patients older than 1 year of age. In infants with persistently elevated right ventricular pressure, reoperation rate was high and had to be compared with other established surgical options.
Abstract: OBJECTIVES: Our objective was to evaluate the short-term safety and efficacy of cardiac resynchronization therapy (CRT) in children. BACKGROUND: Cardiac resynchronization therapy has been beneficial for adult patients with poor left ventricular function and intraventricular conduction delay. The efficacy of this therapy in the young and in those with congenital heart disease (CHD) has not yet been established. METHODS: This is a multi-center, retrospective evaluation of CRT in 103 patients from 22 institutions. RESULTS: Median age at time of implantation was 12.8 years (3 months to 55.4 years). Median duration of follow-up was four months (22 days to 1 year). The diagnosis was CHD in 73 patients (71%), cardiomyopathy in 16 (16%), and congenital complete atrioventricular block in 14 (13%). The QRS duration before pacing was 166.1 +/- 33.3 ms, which decreased after CRT by 37.7 +/- 30.7 ms (p < 0.01). Pre-CRT systemic ventricular ejection fraction (EF) was 26.2 +/- 11.6%. The EF increased by 12.8 +/- 12.7 EF units with a mean EF after CRT of 39.9 +/- 14.8% (p < 0.05). Of 18 patients who underwent CRT while listed for heart transplantation, 3 improved sufficiently to allow removal from the transplant waiting list, 5 underwent transplant, 2 died, and 8 others are currently awaiting transplant. CONCLUSIONS: Cardiac resynchronization therapy appears to offer benefit in pediatric and CHD patients who differ substantially from the adult populations in whom this therapy has been most thoroughly evaluated to date. Further studies looking at the long-term benefit of this therapy in this population are needed.
Abstract: OBJECTIVE: To examine coagulation factors and liver function test abnormalities in patients after total cavopulmonary connection (TCPC). DESIGN: Cross sectional study comprising clinical and echocardiographic evaluation, and biochemical and coagulation profile screening. SETTING: Tertiary referral centre. METHODS: 102 patients aged 4-24 years (median 10 years) at one to eight years (median five years) after TCPC were examined. All patients were maintained on a low dose of aspirin. 96% of patients were in a good clinical condition (New York Heart Association class I or II). No intracardiac thrombi were detected on echocardiography and ventricular function was good in 91% of patients. RESULTS: Total bilirubin was increased in 27% and gamma glutamyltransferase in 54% of patients. Serum total protein, albumin, and prealbumin were normal in almost in all patients. Compared with the control group, patients after TCPC had significantly lower fibrinogen, factor V, factor VII, and protein C concentrations, prolonged international normalised ratio, and increased antithrombin III concentration. Factor V concentration was abnormally decreased in 35%, factor VII in 16%, and protein C in 28% of patients. Antithrombin III was increased in 23% of patients. Factor VII, factor V, protein C, and antithrombin III correlated significantly with serum prealbumin. There was also a significant correlation between procoagulant factor VII and both anticoagulant protein C and antithrombin III. CONCLUSIONS: Almost half of patients after TCPC had laboratory signs of mild cholestasis. Decreased liver synthesis of procoagulant and anticoagulant factors was observed but overall coagulation homeostasis appeared to be in balance in this selected group of patients with a good clinical outcome.
Abstract: OBJECTIVES: This study aimed to evaluate the technical feasibility and hemodynamic benefit of cardiac resynchronization therapy (CRT) in patients with systemic right ventricle (RV). BACKGROUND: Patients with a systemic RV are at high risk of developing heart failure. Cardiac resynchronization therapy may improve RV function in those with electromechanical dyssynchrony. METHODS: Eight patients (age 6.9 to 29.2 years) with a systemic RV and right bundle-branch block (n = 2) or pacing from the left ventricle (LV) (n = 6) with a QRS interval of 161 +/- 21 ms underwent CRT (associated with cardiac surgery aimed at decrease in tricuspid regurgitation in 3 of 8 patients) and were followed-up for a median of 17.4 months. RESULTS: Change from baseline rhythm to CRT was accompanied by a decrease in QRS interval (-28.0%, p = 0.002) and interventricular mechanical delay (-16.7%, p = 0.047) and immediate improvement in the RV filling time (+10.9%, p = 0.002), Tei index (-7.7%, p = 0.008), estimated RV maximum +dP/dt(+45.9%, p = 0.007), aortic velocity-time integral (+7.0%, p = 0.028), and RV ejection fraction by radionuclide ventriculography (+9.6%, p = 0.04). The RV fractional area of change increased from a median of 18.1% before resynchronization to 29.5% at last follow-up (p = 0.008) without a significant change in the end-diastolic area (+4.0%, p = NS). CONCLUSIONS: The CRT yielded improvement in systemic RV function in patients with spontaneous or LV pacing-induced electromechanical dyssynchrony and seems to be a promising adjunct to the treatment and prevention of systemic RV failure.
Abstract: The etiology of dilated cardiomyopathy associated with congenital complete AV block has not yet been clarified. Two infants with AV block of autoimmune and surgical etiology, respectively, had received a dual-chamber right ventricular-based pacemaker and developed dilated cardiomyopathy with severe septal to left ventricular free-wall dyssynchrony 3.4 (0.9) years later. After 4 weeks of biventricular pacing and spontaneous junctional narrow QRS rhythm, respectively, both children showed significant improvement in left ventricular function along with reverse remodeling. Thus, electromechanical dyssynchrony associated with conventional right-ventricular-based DDD pacing may play a significant role in the development of dilated cardiomyopathy in the young.
Abstract: Junctional ectopic tachycardia (JET) is a life-threatening arrhythmia frequently seen after surgical correction of congenital heart defects. This study evaluates the use of a modified, commercially available temporary dual chamber pacemaker used to reestablish AV synchrony by R wave synchronized atrial pacing, a technique not routinely applied because of a lack of appropriate equipment. Ten consecutive children with postoperative JET (median maximum heart rate 185, range 130-240 beats/min) age 0.3-45 (median 5.2) months were studied. R wave synchronized atrial pacing was performed using the VAT mode with inverse connection of the pacing wires (effectively AVT mode), short postventricular atrial refractory period (100 ms), and long AV (effectively VA) delay. AV delay was adjusted to achieve maximum increase in arterial pressure by optimal AV resynchronization. Pacing was successfully applied in all patients for a median period of 29 (range 10-96) hours until tachycardia cessation and led to an immediate increase in systolic, mean, and pulse pressure by 8.9 +/- 3.2 (P < 0.001), 8.1 +/- 4.0 (P < 0.001), and 11.9 +/- 7.8% (P < 0.005), respectively. Two patients developed pacemaker-mediated tachycardia, which could be easily stopped by AV (effectively VA) delay prolongation. Atrial flutter was induced in one patient by asynchronous atrial pacing during the VAT (effectively AVT) mode and managed by overdrive pacing. In conclusion, R wave synchronized atrial pacing could be easily performed using a modified, commercially available temporary dual chamber pacemaker. Significant hemodynamic benefit was achieved due to optimal AV resynchronization at intrinsic heart rate and spontaneous ventricular activation sequence. R wave synchronized atrial pacing should be included in the standard management protocol of postoperative JET.
Abstract: Thirteen patients with d-transposition of the great arteries after the Mustard/Senning procedure underwent electrophysiological study for recurrent intraatrial reentrant tachycardia (IARTs). In 8 patients, a 20-pole electrode catheter and a steerable 7F mapping and ablation catheter were placed in the systemic venous atrium, and via the retrograde route in the pulmonary venous atrium, if required. During IART pace mapping and entrainment mapping were performed in order to localize protected areas of atrial tissue between anatomical and/or surgical barriers of electrical isolation. The systemic venous atrium of 5 patients was studied using the non-contact mapping system (Ensite 3000(TM)). Linear radiofrequency current lesions were induced after mapping of electrical protected areas from the medial aspect of the superior caval vein to the systemic venous atrium and/or intraatrial baffle or the intraatrial suture line in 4 patients, from the medial aspect of mitral valve annulus to the inferior caval vein in 5 patients, from the intraatrial suture line to the posterior systemic venous atrium in 1 patient and in 2 patients from the posterior and inferior pulmonary venous atrium to the tricuspid valve annulus. Subsequently, 14 of the 15 identified IARTs were not inducible during repeated programmed stimulation. Mean duration of the electrophysiological study was 202 min, mean fluoroscopy time was 21.6 min. During follow-up (mean 20 months), 10 of 12 patients with successful procedures are free of tachycardia, 2 patients developed IARTs with a new morphology. In the majority of our patients, curative treatment was feasible by induction of linear radiofrequency current lesions by primarily targeting electrical protected areas of atrial tissue in the systemic venous atrium.
Abstract: The supraventricular tachycardia represents the life threatening disease, which may cause severe heart failure or even during foetal life. The authors present case report of the foetus aged 23 weeks of gestation in whom the supraventricular tachycardia was resistant to standard transplacental treatment by using digoxin and sotalol. The successful rhythm conversion was achieved by intracordal infusion of amiodarone. Further uncomplicated course of pregnancy reached term and healthy boy was subsequently born without having additional psychomotoric complications.
Abstract: BACKGROUND: Chronic pulmonary regurgitation after repair of tetralogy of Fallot (TOF) may lead to right ventricular dilatation, which may be accompanied by ventricular tachycardia and sudden death. We aimed to examine the effects of pulmonary valve replacement (PVR) on (1) certain electrocardiographic markers predictive of monomorphic ventricular arrhythmia and sudden death and (2) sustained atrial flutter/fibrillation and monomorphic ventricular tachycardia. METHODS AND RESULTS: We studied 70 patients who underwent PVR for pulmonary regurgitation and/or right ventricular outflow tract obstruction late after repair of TOF. Maximum QRS duration and QT dispersion were measured from standard ECGs before PVR and at the latest follow-up. Arrhythmia was defined as sustained atrial flutter/fibrillation or sustained monomorphic ventricular tachycardia. Concomitant intraoperative electrophysiological mapping and/or cryoablation were performed in 9 patients (60%) with preexisting ventricular tachycardia and 6 patients (50%) with preexisting atrial flutter. QRS duration remained unchanged in the study group (P=0.46), but it was significantly prolonged (P<0.001) in a comparable group of patients with repaired TOF who did not undergo PVR. At a mean follow-up of 4.7 years, the incidence of ventricular tachycardia diminished from 22% to 9% (P<0.001), and atrial flutter/fibrillation decreased from 17% to 12% (P=0.32). Intraoperative ablation prevented recurrence of preexisting tachyarrhythmia (0 of 15 patients). CONCLUSIONS: PVR in patients with previous TOF repair and chronic pulmonary regurgitation leads to stabilization of QRS duration and, in conjunction with intraoperative cryoablation, to a decrease in the incidence of preexisting atrial and ventricular tachyarrhythmia. When applicable, this combined approach should be used in patients late after repair of TOF.
Abstract: The acute hemodynamic effect of atrioventricular (AV) and inter/intraventricular (IV) resynchronization accomplished by temporary pacing using multiple epicardial pacing wires was evaluated in 20 children (aged 3.4 months to 14.0 years) after surgery for congenital heart defects fulfilling the following criteria: (1) presence of AV and/or IV conduction delay, and (2) need for inotropic support. AV resynchronization (n = 13) was achieved by AV delay optimization during atrial synchronous right ventricular outflow tract pacing. IV resynchronization (n = 14) was accomplished by atrial synchronous pacing from the right ventricular lateral wall in 7 patients with right bundle branch block and normal AV conduction and by atrial synchronous multisite ventricular pacing in another 7 patients with previously performed AV resynchronization. Compared with baseline values, AV resynchronization resulted in an increase in arterial systolic, mean, and pulse pressures by 7.2 +/- 8.3% (p <0.01), 8.6 +/- 8.1% (p <0.005), and 6.9 +/- 13.5% (p = NS), respectively. IV resynchronization used either alone or added to previously performed AV resynchronization led to a pressure increase of 7.0 +/- 4.7%, 5.9 +/- 4.7%, and 9.4 +/- 7.8%, respectively (p <0.001 for all). The combined effect of AV and IV resynchronization resulted in a systolic, mean, and pulse pressure increase of 10.2 +/- 5.0% (range 4.0 to 19.1), 8.6 +/- 5.4% (range 0.8 to 14.8), and 15.2 +/- 8.5% (range 6.1 to 33.3), respectively (p <0.001 for all). The increase in systolic arterial pressure after IV resynchronization was positively correlated with the initial QRS duration (r = 0.62, p <0.05) and extent of QRS shortening (r = 0.66, p <0.05). In conclusion, resynchronization pacing led to a significant increase in arterial blood pressure and was a useful adjunct to the treatment of acute postoperative heart failure in patients with AV and/or IV conduction delay.
Abstract: BACKGROUND: Most adolescents and young adults born with transposition of the great arteries and survivors of Mustard operation are alive today and are leading ordinary lives. How far is the quality of their life influenced by residual findings? METHODS: We have analysed the oldest group of 177 children operated on with the Mustard procedure during 1979-1984 from our total experience of 609 corrections of transposition of the great arteries until 1996. In the long-term follow-up 12 to 18 years after Mustard operation the clinical investigation, 24 hours ECG Holter monitoring, 2D and colour flow Doppler echocardiography, radionuclide angiocardiography and exercise testing were performed. RESULTS: Basic sinus rhythm had 61% of 137 survivors, sinus node dysfunction had 51%. All but 4 patients needed no antiarrhythmic therapy. There were 10 sudden deaths. Severe tricuspid valve regurgitation developed in 15.9% of children, and decreased to 6% after intensive medical treatment. The right ventricular systolic dysfunction was found on radionuclide ventriculography in 8% of children after surgery. The left ventricular ejection fraction was subnormal in 10% and left ventricular diastolic function expressed by rapid filling fraction was subnormal in 80% of patients and may cause inability to increase cardiac output at exercise The obstruction of caval veins was found in 9%. There were neurological complications in 13.3% (10% already preoperatively) but severe brain damage was found in 4.4% only. CONCLUSIONS: Exercise tolerance with the maximum oxygen consumption over 30 ml/kg/min in 96% of investigated children suggests the good ability and full efficiency for recreation sports. Most survivors (84%) are reported to lead ordinary lives and function in NYHA class I.
Abstract: Disturbance of normal AV synchrony and dyssynchronous ventricular contraction may be deleterious in patients with otherwise compromised hemodynamics. This study evaluated the effect of hemodynamically optimized temporary dual chamber pacing in patients after surgery for congenital heart disease. Pacing was performed in 23 children aged 5 days to 7.7 years (median 7.3 months) with various postoperative dysrhythmias, low cardiac output, and/or high inotropic support and optimized to achieve the highest systolic and mean arterial pressures. The following four pacing modes were used: (1) AV synchronous or AV sequential pacing with individually optimized AV delay in 11 patients with first- to third-degree AV block; (2) AV sequential pacing using transesophageal atrial pacing in combination with a temporary DDD pacemaker for atrial tracking and ventricular pacing in three patients with third-degree AV block and junctional ectopic tachycardia, respectively, who had poor signal and exit block on atrial epicardial pacing wires; (3) R wave synchronized atrial pacing in eight patients with junctional ectopic tachycardia and impaired antegrade AV conduction precluding the use of atrial overdrive pacing; (4) Atrio-biventricular sequential pacing in two patients. Pressures measured during optimized pacing were compared to baseline values at underlying rhythm (13 patients with first-degree AV block or junctional ectopic tachycardia) or during pacing modes commonly used in the given clinical situation: AAI pacing (1 patient with slow junctional rhythm and first-degree AV block during atrial pacing), VVI pacing (2 patients with third-degree AV block and exit block and poor sensing on epicardial atrial pacing wires) and dual-chamber pacing with AV delays set to 100 ms (atrial tracking) or 150 ms (AV sequential pacing) in 7 patients with second- to third-degree AV block and functional atrial pacing wires. Optimized pacing led to a significant increase in arterial systolic (mean) pressure from 71.5 +/- 12.5 (52.3 +/- 9.0) to 80.5 +/- 12.2 (59.7 +/- 9.1) mmHg (P < 0.001 for both) and a decrease in central venous (left atrial) pressure from 12.3 +/- 3.4 (10.5 +/- 3.2) to 11.0 +/- 3.0 (9.2 +/- 2.7) mmHg (P < 0.001 and < 0.005, respectively). In conclusion, several techniques of individually optimized temporary dual chamber pacing leading to optimal AV synchrony and/or synchronous ventricular contraction were successfully used to improve hemodynamics in patients with heart failure and selected dysrhythmias after congenital heart surgery.
Abstract: The surgical technique and tactics of the Norwood operation in neonates with hypoplastic left heart syndrome represent a surgical challenge. The Norwood operation was performed from the midline sternotomy approach, in extracorporeal circulation and deep hypothermic circulatory arrest was used for reconstruction of the hypoplastic aorta. Operation consisted of reconstruction of the "neoaorta" and the aortic arch from the original hypoplastic ascendent aorta, pulmonary trunk and a patch cut from a pulmonary homograft or pericardium, excision of the atrial septum and an arterial shunt from a Goretex vascular graft 3.5 or 4 mm in diameter. In patients with well developed aortic arch it was possible to reconstruct the aorta using Damus-Kaye-Stansel operation without circulatory arrest. Out of 12 operated patients with this defect, two (16.7%) died during the early postoperative period, one patient died late. The postoperative course was often complicated. In 6 (50.0%) patients the second step of Norwood operation, the bidirectional cavopulmonary anastomosis, was performed without mortality. According to our experience, it was necessary to prepare patients adequately before the first surgery. Perfect reconstruction of the aorta and a well functioning shunt had the crucial significance.
Abstract: Severe tracheal stenosis represents a life threatening malformation which necessitates early surgery. Two patients aged one and two years, respectively, were followed-up for signs of congenital stridor. Following respiratory infection both children became critically ill with severe dyspnoea necessitating intubation and artificial ventilation. In the first patient, echocardiography, tracheobronchoscopy and other investigations revealed a pulmonary artery sling with tracheal compression and hypoplasia of the whole trachea. In the second child, presence of a short local tracheal stenosis was found, the cause of which could not be clarified. In the patient with the pulmonary sling, resection and reimplantation of the anomalous left pulmonary artery was performed first. In both children, however, surgical reconstruction of the lower airways was necessary. Surgery was performed from a midline sternotomy approach in extracorporeal circulation. The hypoplastic trachea with circular rings in the first child was enlarged with a pericardial patch. In the second child, the local tracheal stenosis was resected and a direct anastomosis of the trachea was performed. In both patients, transient formation of granulations was observed. Both children, however, survived and their clinical condition remains good 18 and 9 months, respectively, after surgery. Tracheobronchoscopic controls show very good result. Our experience confirms the possibility of successful surgical reconstruction of lower airways in young children using extracorporeal circulation. Good interdisciplinary cooperation between the surgeon and other specialists is an important prerequisite of good surgical results.
Abstract: This study was designed to assess adverse effects of oral propafenone in a large number of pediatric patients. Retrospective data from 27 European centers covering 772 patients treated with oral propafenone were analyzed. The following arrhythmias were treated: reentrant supraventricular tachycardia in 388 patients, atrial ectopic tachycardia in 66, junctional ectopic tachycardia in 39, atrial flutter in 21, ventricular premature complexes in 140, ventricular tachycardia in 78, and other arrhythmias in 39 patients. Two hundred forty-nine patients (32.3%) had structural heart disease. Significant electrophysiologic side effects and proarrhythmia were found in 15 of 772 patients (1.9%): sinus node dysfunction in 4, complete atrioventricular block in 2, aggravation of supraventricular tachycardia in 2, acceleration of ventricular rate during atrial flutter in 1, ventricular proarrhythmia in 5, and unexplained syncope in 1 patient. Cardiac arrest or sudden death occurred in 5 of 772 patients (0.6%): 2 patients had supraventricular tachycardia due to the Wolff-Parkinson-White syndrome and a normal heart; the remaining 3 patients had structural heart disease. Overall, adverse cardiac events were more common in the presence (12 of 249 patients, 4.8%) than in the absence (8 of 523 patients, 1.5%) of structural heart disease (p <0.01). There was no difference between patients treated for supraventricular and ventricular arrhythmias. Thus, propafenone is a relatively safe drug for the treatment of several pediatric tachyarrhythmias. Proarrhythmic effects seem to be less frequent than those reported for encainide or flecainide and occur predominantly in patients with structural heart disease.
Abstract: BACKGROUND: Reoperations in cardiac surgery of congenital heart defects represent not only the difficult technical problem but also a prognostic one. They are demanding reconstructive procedures with broad spectrum of hazards and are definitely cumulating the operative risk. METHODS AND RESULTS: At the Pediatric Kardiocentrum, University Hospital Motol, Prague, there were 2250 children operated on for congenital heart defects in the first year of life and followed up during 1969-1996. There were 1701 primary corrections (75%) and 549 palliative procedures (25%). After operation 1912 survivors (85%) were followed-up to 25 years. Later on 524 children (27%) were reoperated with 672 procedures. There were three main reasons for reoperation: 1. Staged procedures of complex heart defects in 477 children. 2. One hundred seventy four reoperations for residual defects were performed after primary procedure in 123 infants. There were 11 corrections of residual intracardiac shunts and 120 repairs of residual stenoses. There were 58 repairs of recoarctation, 40 pulmonary artery reconstructions after arterial shunts and 43 reoperations on valves for restenosis or worsened regurgitation. 3. Other 21 extracardiac complications of primary operation were solved by pacemaker implantation (8), plication of paralysed diaphragm (6), chylothorax (3) and other (4). The causes of reoperations represent 7 main categories: 1. Solid scars, adhesions and fibrous bands cause stenoses. 2. Palliative procedures influence positively the hemodynamics, but compromise the development and growth of myocardial wall. 3. Synthetic materials are nor growing but produce obstructions. 5. Incomplete primary correction and technical errors. 6. Iatrogenic injury of the phrenic nerve or the bundle of His. 7. False diagnosis. The hazards of reoperations are: 1. High risk of resternotomy with catastrophic bleeding. 2. Difficult cannulation for heart-lung bypass, and problematic induction of cardioplegia. 3. Difficult dissection of all structures with the high risk of bleeding on the site of aorta, lung hilum or coronary arteries. 4. Difficult left heart decompression and defibrillation of the heart. 5. Paralysis of the diaphragm. CONCLUSIONS: Staged procedures are the major source of reoperations. Their volume does not change much and it is difficult to influence it because still a large number of complex heart defects are operated every year. On the contrary the residual or recurrent defects as well as a number of further complications can be influenced by preventive measures during primary operation.
Abstract: In the Kardiocentrum, University Hospital Motol, Prague, protocol of the primary repair of interrupted aortic arch was introduced, and between 1993-1997, 15 neonates aged 1-26 days (median 5 days) were operated on. Treatment with prostaglandins E for maintenance of the ductal patency, correction of metabolic acidosis, and treatment of all complications were necessary before surgery. The correction was performed from the midline sternotomy approach, in extracorporeal circulation and deep hypothermia with circulatory arrest. Direct anastomosis between the ascending and the descending aorta was possible in all the patients. At the same time, associated heart lesions were corrected (ventricular septal defect in 13, persistent truncus arteriosus in 3, subaortic stenosis in 2, transposition of the great arteries, double-outlet right ventricle and aortico-pulmonary window in 1 patient, each). Four (26.7%) patients died after surgery. Out of the first 6 neonates 3 (50.0%) died, but out of the subsequent 9 patients only 1 (11.1%) died. Reoperation was necessary in 2 patients. All 11 early survivors are alive and doing well 8-54 months after the repair. In one of them restenosis at the site of aortic anastomosis and hemodynamically significant subaortic stenosis occurred. All the remaining patients have a nonrestrictive aortic anastomosis. Primary repair of interrupted aortic arch and associated heart lesions can be performed in a neonate with reasonable mortality. Treatment of complications is necessary before surgery. Results depend especially on the patient's clinical condition and experience of the center.
Abstract: OBJECTIVE: Early results of primary and two-stage repair of interrupted aortic arch have improved. Experience with different surgical approaches should be analysed and compared. METHODS: Forty neonates and infants with interrupted aortic arch underwent primary repair (19 patients) or palliative operation (21 patients). Twenty (50%) patients were followed-up for 5.1+/-4.3 years. All patients were regularly examined with the aim of determining clinical development, presence of residual lesions or complications and need for re-intervention. Aortic arch and the left ventricular outflow tract growth were assessed by echocardiographic examination. Data from hospital and outpatient department records were analysed. RESULTS: The early mortality was 61.9% after palliative operations and 36.8% after the primary repair. Presence of complications (P < 0.001), earlier year of surgery (P < 0.01), bad clinical condition and acidosis (P < 0.05) represented statistically significant risk factors for death in the whole series. In seven (87.5%) out of eight early survivors, after the initial palliative operation, closure of ventricular septal defect and debanding were done, and in three (37.5%) patients, re-operation for aortic arch obstruction was also required. Out of 12 patients, after the primary repair, one required early re-operation for persistent left ventricular outflow tract obstruction and two needed late re-intervention for left bronchus obstruction. In three (25%) patients, after the primary repair, left ventricular outflow tract obstruction with a maximal systolic pressure gradient higher than 30 mmHg developed. At present, all 20 early survivors are alive. Five patients, after palliative operation, are in NYHA class 1, but in three patients, who are in class III or IV, the outcome is influenced by severe complications. All patients after the primary repair are in class I or II. CONCLUSIONS: Our experience confirmed better results after the primary repair of interrupted aortic arch, which was associated with lower mortality, prevalence of severe complications and need for re-intervention. Higher prevalence of subaortic stenosis after primary repair could be explained by patient selection early in our experience. We recommend the primary repair of interrupted aortic arch and associated heart lesions in neonates, however, in unfavourable conditions an individualised surgical approach with initial palliative surgery should be considered.
Abstract: Primary repair of interrupted aortic arch and associated heart lesions was performed in 13 patients aged from 1 to 85 days. The surgery was performed through the midline sternotomy approach in extracorporeal circulation and deep hypothermia. Hypothermic circulatory arrest at 14 to 19 degrees C was used for reconstruction of the aortic arch. In all patients it was possible to perform a direct anastomosis between the ascendent and descendent aorta. At the same time closure of the ventricular septal defect was performed in 11 patients, closure of the atrial septal defect in 4, correction of persistent truncus arteriosus in 3, resection of subaortic stenosis in 2, arterial switch repair of transposition of the great arteries in 1, correction of double outlet right ventricle in 1 and patch closure of aortico-pulmonary window in 1 patient. Three (23.1%) newborns died in the early postoperative period: two from sepsis and one from multiple organ failure. Ten patients (76.9%) were followed up for 1 to 29 months postoperatively. All of them are in very good condition with a nonrestrictive aortic anastomosis. Primary one-stage repair of interrupted aortic arch and associated heart lesions is preferred to the two-stage repair in all newborns with this critical congenital heart disease.
Abstract: The cause of paresis of the diaphragm after cardiosurgery is damage of the phrenic nerve. The diagnosis of paresis is based on X-ray examination, sonography and electromyography of the diaphragm. Plication of the diaphragm is indicated only in those children with paresis of the diaphragm who develop during spontaneous ventilation severe respiratory insufficiency. In the Cardiocentre of the Faculty Hospital Prague-Motol between 1983 and 1996 of 5333 children operated on account of heart disease 29 children were subjected to plication of the diaphragm, incl. five where the operation was made during the neonatal stage (17%), 20 in infant age (69%) and four were older than one year (14%). By the third day after plication 9 children (38%) could be disconnected from the respirator, by the 5th day 20 children (70%) by the 7th day 22 children (75%). In neonates and infants with postoperative paresis of the diaphragm, where spontaneous ventilation cannot be induced, plication of the diaphragm is according to the authors the method of choice. It is a rapid and safe surgical operation which reduces the period of artificial ventilation and its complications.
Abstract: OBJECTIVE: Analysis of mortality and morbidity of patients treated by primary total cavopulmonary connection (TCPC)-Primary correction group, and comparison to patients treated by bidirectional Glenn (BDG) followed by total cavopulmonary connection-two stage TCPC group. METHODS: Retrospective study of 123 consecutive patients who underwent 144 different types of cavopulmonary connections between 1987-1995: bidirectional Glenn 59, HemiFontan operation 10, primary total cavopulmonary connection 54, and total cavopulmonary connection completion after previous bidirectional Glenn 21. Important preoperative risk factors: age, systemic outflow obstruction, pulmonary venous obstruction, pulmonary artery (PA) hypoplasia (McGoon ratio), PA stenosis/distortion, PA mean pressure, PA vascular resistance, atrioventricular valve regurgitation, systolic and diastolic ventricular function and ventricular hypertrophy were re-evaluated according to Texas Heart Institution Scoring System in both groups. Three different preoperative risk groups were established: low risk, score (0-3) moderate risk (4,5) and high risk score (> or = 6). RESULTS: Mean age was 85.2 month (range 16.1-229.5 months) and 106.6 months (range 42.6-178.9 months) in primary correction group and two stage TCPC group, respectively. Diagnosis was similar in both groups, majority having univentricular heart or hypoplastic one ventricle. Initial palliation (pulmonary artery banding, modified aortopulmonary shunt, coarctation repair etc.) was performed in 38 (70.3%) patients of primary correction group and in 12 (57.1%) two stage TCPC group. The mortality was 7.4% (4 out of 54) and 14.2% (3 out of 21) for primary correction and two stage TCPC group, respectively. There were two take down in the primary correction group. There was no late death in either group. Operative data and postoperative morbidity did not statistically differ in both groups. CONCLUSION: Until 1993 bidirectional Glenn was preferred to primary total cavopulmonary connection for high risk patients. High mortality 14.2% patients of two stage TCPC group vs. 7.4% of primary correction group in patients with the same preoperative hazard led us to change our policy. We now prefer primary TCPC for all patients with functional single ventricle and surgically correctable major associated defects. High risk patients undergo TCPC with fenestration. Patients not suitable for TCPC undergo either HemiFontan operation or some type of initial palliative procedure.
Abstract: OBJECTIVE: The objective of this study was to evaluate the effect of nutritional support on proteolysis and plasma amino acid profile in infants early after cardiac operations for congenital heart defects. METHODS: Thirty-seven patients, 2 to 12 months old, were randomized on postoperative day 1 for 24-hour isocaloric metabolic study. Group STANDARD (18 patients) received glucose as the maintenance fluid, and group PN (19 patients) received glucose and crystalloid amino acid solution at a dosage of 0.8 +/- 0.1 gm/kg per day. The nonprotein caloric intake in the two groups was 25 +/- 15 and 33 +/- 9 kcal/kg, respectively (p = not significant). RESULTS: The nitrogen balance was markedly less negative in group PN than in group STANDARD (-114 +/- 81 vs -244 +/- 86 mg/kg, respectively, p = 0.001). There was a highly significant inverse correlation between the nitrogen balance and urinary 3-methylhistidine excretion in both groups, but the muscle proteolysis was blunted more effectively in patients receiving amino acids. Concentrations of the plasmatic branched-chain amino acids, alanine, glycine, and proline, decreased significantly in group STANDARD but not in group PN on postoperative day 2. Glutamine and threonine levels declined significantly on postoperative day 2 in both groups. Low levels of arginine were observed in our patients before operation and in the early postoperative period. The amino acid concentrations normalized on postoperative day 7 in all patients. CONCLUSION: Significant proteolysis and hypoaminoacidemia were observed in infants early after cardiac operations. This hypercatabolic response was blunted by parenteral nutritional support.
Abstract: From September 1977 to October 1995, 287 patients with atrioventricular septal defect (AVSD) aged from 2 months of 21 years underwent total repair in Kardiocentrum in prague. In 97 patients complete, in 20 transitional and in 170 patients partial form of AVSD was present. The repair consisted of closure of the defect and individually modified reconstruction of two atrioventricular (AV) orifices. In cases with a common orifice a two-patch technique was used. Fixation of undivided anterior and posterior common leaflets to patches in an appropriate level was essential in combination with complete closure of the cleft. Incomplete closure of the cleft was performed if potentially stenotic morphology was present. Commissuroplasty with pladgeted mattress stitches was done in patients with dilated annulus and commissuroplasty with a single stitch was performed if the annulus was not dilated. The methods were similar in cases with two AV orifices. The AV valve repair was difficult in the presence of severe regurgitation in valves with potentially stenotic morphology. Of the 287 operated patients 26 (9.1%) died during the early postoperative period. Mortality was 19.6% in the complete form and 3.7% in the partial and transitional forms. The mortality depended on morphology of the left atrioventricular valve. Potentially stenotic valvar morphology represented an important risk factor for death and reoperation. It was necessary to reoperate on 18 (6.3%) patients for significant "mitral" valve regurgitation. Reconstruction of a competent left AV valve is the most important step of AVSD repair which must always be modified according to individual morphological and functional abnormalities.
Abstract: METHODS AND RESULTS. From the group of 110 neonates born with transposition of the great arteries during 1991-1994 that were referred for the treatment to Kardiocentrum, University Hospital Prague-Motol, 46 neonates with simple transposition were operated on according to the criteria for anatomical correction (arterial switch) at the mean age of 9 days (4-20 days). Fourteen infants with transposition and large ventricular septal defect were corrected with arterial switch at the mean age of 2.5 months (5 weeks-9 months). Fifty neonates that did not meet criteria for arterial switch procedure were indicated for correction at the atrial level (Senning procedure) that has been performed at the mean age of 5 months (1-10 months). Out of 46 operated neonates 10 died following the operation and one child died 2 months later after surgery. There were 2 death out of last 20 neonates (10%). Thirty five children surviving 1-4 years after anatomical arterial correction of transposition are without complaints in excellent condition, NYHA class I. CONCLUSIONS. The procedure of the anatomical correction at the level of the great arteries (arterial switch) according to Jatene, that has been successfully introduced at Kardiocentrum, University Hospital Prague-Motol, has been reproducible and became the method of choice for operations of transposition of the great arteries in neonates with the suitable anatomy.
Abstract: In Cardiocentrum of the University Hospital in Prague-Motol in 1988-1994 anatomical correction of transposition of the great arteries (arterial switch) was performed in 47 neonates aged 4 to 20 days. The aorta and pulmonary artery were transferred into the appropriate ventricle concurrently with reimplantation of the coronary arteries. The surgical technique was modified with regard to the anatomy of the coronary arteries and the presence of associated cardiac defects. Eleven of the 47 neonates (23%) died during the early postoperative period, one patient died two months after operation. Of the last 20 operated neonates only two died (10%) and both had an abnormal insertion of the coronary arteries. Thirty-five children are followed up for 2-45 months following anatomical correction. All are in a very good clinical condition without serious residual findings. The authors describe the protocol of the diagnostic and therapeutic procedure in transposition of the great arteries. They consider anatomical arterial correction in the neonatal period as the method of choice for this disease. The optimal age for anatomical correction in isolated transposition is between the 7th and 14th day and in transpositions with a major defect of the ventricular septum at the age of one month. The surgical results are steadily improving with accumulating experience. The medium-term results of anatomical correction of transposition of the great arteries are very favourable.
Abstract: This study evaluates the role of late potentials in identifying patients with sustained ventricular tachycardia (VT) after surgery for congenital heart defects using right ventriculotomy. Nine patients with early (1 to 12 months) or late VT (spontaneous in 7 [induced during electrophysiologic study in 6 of the 7] and induced in 2) and 104 patients without VT were studied. All patients had complete right bundle branch block. Late potentials were quantified by 3 time-domain parameters of the signal-averaged electrocardiogram: total filtered QRS duration, root-mean-square voltage in the last 40 ms, and low-amplitude signal duration of the terminal filtered QRS complex. Root-mean-square voltage filtered at 80 to 250 Hz was lower in patients with than without VT (9 +/- 6 vs 16 +/- 8 microV, p < 0.01). By multivariate analysis, more complex surgery (i.e., insertion of extracardiac conduits, Kawashima operation, etc.), lower root-mean-square voltage, and higher Lown grade (2 to 5) of ventricular arrhythmias on routine postoperative Holter recordings were the only independent predictors of VT (p < 0.001, < 0.05, and < 0.05, respectively). A combination of more complex surgery, root-mean-square voltage < 14 microV, and Lown grade 2 to 5 ventricular arrhythmias was highly predictive of VT (positive predictive value 75%). Conversely, patients without complex surgery and with root-mean-square voltage of > 13 microV were not likely to develop VT (negative predictive value 100%). Late potentials are an independent predictor of VT and may improve the identification of patients at low and high risk of VT after surgery for congenital heart defects using right ventriculotomy.
Abstract: Primary correction of an interrupted aortic arch was performed in seven neonates aged 2 to 26 days. The operation was performed from median sternotomy with extracorporeal circulation using hypothermic arrest of the circulation for reconstruction of the aortic arch. In all neonates it proved possible to make a direct anastomosis of the ascendent and descendent aorta. At the same time in six children a defect of the ventricular septum was closed, in two the common arterial trunk was corrected, in one resection of subaortic stenosis was performed and in another child correction of the aortopulmonary window. After the operation three neonates died from sepsis and multiorgan failure. At present four patients are alive who, 10 to 20 months after operation, are in a good condition. All have a non-restrictive anastomosis of the aorta. Primary correction of an interrupted aortic arch and associated defects is preferred by the authors to two-stage surgery.
Abstract: Total cavopulmonary connection (TCPC) allows surgical treatment of patients with complex univentricular heart disease. Between 1991 and 1993 this operation was performed in 15 cyanotic children with complex heart defects. Age range was 3.5-14 (median 8.3) years. In 5 children with increased operative risk a calibrated interatrial fenestration was created intraoperatively to allow systemic venous decompression. Three patients (20%) died. In remaining 12 patients a significant increase in arterial oxygen saturation and decrease of polycythemia was encountered. All patients remain in a good clinical condition 1-25 months after operation. Noninvasive investigation including echocardiography confirmed good function of the heart.
Abstract: 359 patients after the Mustard (275) or Senning (84) operations for transposition of the great arteries were followed-up for a mean of 103.7 (range 0.4 to 204) months. 259 patients had postoperative 24-h Holter recordings. In 129 Mustard children serial (mean 4.4) postoperative Holter recordings were available for evaluation. Criteria based on Holter and scalar electrocardiograms at normal sinus node functions were used for rhythm analysis. Postoperative dysrhythmias appeared in 70% of the patients: sinus node dysfunction in 62.8%, second or third degree atrioventricular block in 3.2%, sustained atrial tachycardia or atrial flutter in 4.5%, and significant ventricular arrhythmia (Lown 2-5) in 21.4%. The prevalence of sinus node dysfunction increased slightly from 50.8% during the first 2 postoperative years to 64.4% in patients more than 10 years postoperatively. Fifteen patients (4.2%) died suddenly during follow-up. By multivariate analysis severe tricuspid regurgitation and/or right ventricular dysfunction and uncontrolled supraventricular tachydysrhythmias were identified as the two significant risk factors for sudden death.
Abstract: Propafenone hydrochloride, a class 1C antiarrhythmic agent, combines sodium channel-blocking effects with beta-blocking capacities and a weak calcium antagonism. The drug exerts marked electrophysiologic effects on accessory atrioventricular pathways. In patients with atrioventricular nodal reentry tachycardia, propafenone is able to block conduction in the fast conducting pathway. In addition, propafenone is very effective in young patients with supraventricular tachycardia based on enhanced abnormal automaticity. In pediatric patients, left ventricular performance remains unimpaired. Proarrhythmic events have been noted in children only occasionally. In accordance with the electrophysiologic profile, intravenous and oral propafenone is an effective agent for treatment of supraventricular tachycardia based on a reentry mechanism and due to abnormal automaticity (i.e., supraventricular tachycardia based on an accessory atrioventricular pathway, atrioventricular nodal reentry tachycardia, junctional ectopic tachycardia, and atrial ectopic tachycardia). In children with ventricular dysrhythmias, efficacy seems to be related to the underlying cardiac diagnosis. Propafenone is well tolerated in the majority of young patients. Incidence of proarrhythmic events seems to be lower with propafenone than with other class 1C agents. However, the risk of these serious adverse events should be taken into account when therapy with propafenone is considered, particularly in patients with structural heart disease.
Abstract: Bidirectional cavopulmonary anastomosis was used during the past six years for palliative treatment of 34 children with complex cardiac disease with a low pulmonary blood flow and a functional common ventricle. The age at the time of operation was 5 months to 16 years (median 55 months). Two children (5.9%) died soon after operation and one patient died in conjunction with reoperation seven months later. After operation a significant increase of saturation and decrease of the haematocrit occurred in all patients. The condition of 31 patients during an out-patient check-up 2-64 months after operation was satisfactory and postoperative examinations revealed a satisfactory function of the anastomosis.
Abstract: The relation between propafenone dose, serum level, electrocardiographic parameters, antiarrhythmic drug efficacy and adverse effects was studied in 47 children with symptomatic supraventricular arrhythmias aged 1 day to 10.3 years (median 2.2 months) with a mean follow-up of 14.3 months. Propafenone trough serum levels were measured using gas chromatography. Oral propafenone (mean dose 353 mg/m2/day) was effective in 41 of the 47 patients (87.2%). Serum levels did not differ between patients responding and not responding to propafenone (0.45 +/- 0.40 vs 0.36 +/- 0.41 mg/liter). PR interval and QRS complex duration increased more significantly with propafenone dose increments (p < 0.001), than with propafenone serum levels (p < 0.05). At successful treatment PR interval and QRS complex were prolonged by a mean of 19.2 and 20.5% compared with pretreatment status. Five patients exhibited unexpected marked QRS complex prolongation (50 to 200%) despite low propafenone dosage (< 300 mg/m2/day) and level ranging from 0.05 to 1.33 mg/liter. Three patients (6.1%) were suspected of being "poor" metabolizers of propafenone. Mild chronic elevation of serum liver enzymes was observed in 5 patients treated with a larger dose (mean 448 mg/m2/day, p < 0.001). No proarrhythmia was noted on serial Holter monitors. One patient with Wolff-Parkinson-White syndrome and a normal heart had cardiac arrest after aspiration. Serial monitoring of PR interval and QRS complex duration was more useful for proper dosage adjustment than propafenone serum levels. Serum liver enzymes should be closely monitored when using higher propafenone doses. Malignant proarrhythmia could not be excluded in the 1 patient with cardiac arrest.
Abstract: OBJECTIVES. Class IC antiarrhythmic drugs have recently been shown to be effective in some patients with atrial ectopic tachycardia. We therefore studied the efficacy of these drugs in patients with congenital junctional ectopic tachycardia. BACKGROUND. Follow-up data on patients with junctional ectopic tachycardia suggest that this potentially lethal arrhythmia may cease spontaneously in a significant proportion of affected children. Therefore, temporary antiarrhythmic treatment appears to be the therapy of choice. METHODS. The efficacy of propafenone was prospectively assessed in four infants with junctional ectopic tachycardia (ventricular rate 180, 185, 210 and 320 beats/min, respectively). The diagnosis of junctional ectopic tachycardia was established before the age of 2 months in all four infants. Propafenone was given orally in a mean dose of 350 (300 to 500) mg/m2 body surface area per day. Success of therapy was determined by serial electrocardiograms (ECGs) and Holter ambulatory ECG monitoring. RESULTS. In two patients, junctional ectopic tachycardia was completely suppressed. In the remaining two patients, the tachycardia rate decreased to less than 150 beats/min. Serum propafenone levels did not correlate with efficacy of treatment. The mean duration of therapy was 18 months (range 3 to 36). No chemical or clinical side effects were noted. CONCLUSIONS. Because of its effectiveness, safety and lack of side effects, propafenone appears to be a valuable drug in the treatment of junctional ectopic tachycardia in newborns and infants.
Abstract: Lyme disease is a systemic illness with skin, neurologic, joint, and cardiac involvement. Absence of typical skin lesion--erythema chronicum migrans--during the first period of disease may cause the diagnosis difficult. Syncope due to complete atrioventricular block was the first symptom of disease in our patient, but no tick bite anamnestic data were available. Quick changes on EKG tracing during cardiac pacing were present. Echocardiography revealed left ventricular dysfunction. Specific immunological tests confirmed the diagnostic suspicion. Cardiac pacing, digitalis and antibiotic treatment ensued in complete recovery. No other systemic lesion appeared. Lyme carditis may be the only manifestation of the disease. Temporary cardiac pacing may be necessary.
Abstract: The article summarizes the present state of view on the causes, risks and possible prevention and treatment of dysrhythmias after surgery for congenital heart disease. Various surgical procedures and their contribution to postoperative dysrhythmias are discussed. Literary data on the incidence of rhythm disturbances after closure of ventricular septal defect, total correction of Fallot tetralogy and Mustard or Senning operation for transposition of the great arteries are reviewed and compared with own findings. Special attention is paid to proved and possible risk factors for sudden cardiac death. A brief review of various therapeutic options (pacing, drugs and surgery) follows.
Abstract: Seven various 24-hour ambulatory ECG systems from six producers (Trendsetter 9000A--Del Mar Avionics, Epicardia HC and PC--Medicomp, Epicardia FD--Hellige, Spacelabs 90,101-Spacelabs, Medilog 4000--Oxford, Laser Holter 8000T--Marquette) were used over a 4-year period to gather the experience with a total of 449 24-hour ECG recordings. The quality of the automatic analysis, the mode of access to the ECG data, control and correction possibilities, operator time consumption, report quality, costs and availability of consumeables were individually evaluated. In the country's specific conditions/shortage of some type of consumeables), Laser Holter 8000T was regarded as the most useful device followed by Epicardia FD and Medilog 4000.
Abstract: 41 patients after surgical correction of the tetralogy of Fall of aged 2-24 years (mean 11.2 y.) were followed for 12-65 months (mean 39.5 m.) for known or suspected dysrhythmias. 24-hour ambulatory ECG and exercise testing demonstrated nonsignificant ventricular ectopy (grade 0-1 according to a modified Lown classification) in 28 patients (group I) and significant (grade 2-5) ventricular dysrhythmias in the remaining 13 patients (group II). There were 2 cases of sudden late death in group II, whereas all patients in group I are alive. The victims of sudden death had no, other serious dysrhythmias and received no antiarrhythmic treatment. Ejection fraction of the functional part of the right ventricle estimated by radionuclide angiocardiography was not different in both groups whereas, global right ventricular ejection fraction differed nearly significantly (group I: 39.6 +/- 8.3%, group II: 31.9 +/- 10.4%, p = 0.052). Thus, a diminished global right ventricular ejection fraction caused by an extensive resection and large patch in the right ventricular outflow tract may be connected with the occurrence of higher grades of ventricular ectopy. These may lead to sudden late death.
Abstract: Transesophageal atrial pacing was used in 29 consecutive patients aged 1 day to 16.5 years (mean 8.04 years) to replace the following procedures: intracardiac electrophysiologic study in patients with selected arrhythmias (21 patients), intracardiac overdrive or synchronized direct current cardioversion of supraventricular tachyarrhythmias or drug administration in patients with acute reciprocating supraventricular tachycardia (9 patients). Atrial capture was achieved without discomfort in 27 patients (93.1%). The diagnostic or therapeutic goal of the procedure was achieved in 26 children (89.7%). Transesophageal atrial pacing may replace intracardiac pacing procedures, direct current cardioversion and drug administration in patients with selected cardiac arrhythmias and has proved appropriate as a first diagnostic or therapeutic step.
Abstract: During the 29th week of gestation the authors diagnosed supraventricular tachycardia of the foetus and pathological echogenity in the region of the mitral valve, most probably of tumourous aetiology. By transplacental digitalization the supraventricular tachycardia was controlled; according to Doppler analysis the tumour did not interfere with the flow to the mitral orifice. Post-natally the diagnosis of a tumour in the left atrium was confirmed. Surgery was so far postponed in view of the normal haemodynamics.
