Abstract: OBJECTIVE: Cardiac resynchronisation therapy has proven to be effective in refractory heart failure (HF) patients with QRS >120-130 ms. Therefore, the aim of our study was to verify the long-term effectiveness of cardiac resynchronisation therapy in HF patients with echocardiographic evidence of mechanical asynchrony regardless of QRS duration. METHODS: One hundred and six patients with New York Heart Association class II-IV HF and echocardiographic documentation of interventricular and intraventricular asynchrony underwent biventricular stimulation. A clinical and functional evaluation was performed at baseline, 1, 3, 6 months, and every 6 months thereafter. RESULTS: After a median follow-up of 16 months, a significant improvement was noted in ejection fraction, left ventricular diameters, mitral regurgitation jet area, interventricular and intraventricular echocardiographic indexes of asynchrony, and the 6-min walking distance (P < 0.001 for all). Death rates for all causes and for cardiac causes were 18.2 (95% confidence interval 12.8-25.9) and 13.5 (95% confidence interval 9.0-20.3) per 100 person-years, respectively. Patients in New York Heart Association class IV had an almost three-fold increase in risk of dying as compared to class II-III (hazard ratio 2.97, 95% confidence interval 1.30-6.79). CONCLUSIONS: Interventricular and intraventricular asynchrony at echocardiography may be useful in identifying HF patients suitable for cardiac resynchronisation therapy, with results comparable to those obtained with QRS duration selection criteria.
Abstract: The risk of sudden death in patients with Brugada syndrome (BS) is still unclear. Moreover, particular clinical conditions may have a confounding effect on the diagnostic and therapeutic approach. We report the case of a 27-year-old man with a clinical history of suspected neurally mediated syncope and typical ECG features of BS. The tilt table test showed a type I, mixed, positive response. The electrophysiological study (EPS) disclosed a peculiar ventricular irritability with the induction of a life-threatening arrhythmia. After the implantation of a cardioverter-defibrillator an episode of ventricular fibrillation during sleep at night was correctly identified and treated by the device. The association between neurally mediated susceptibility and the typical ECG abnormalities of BS is not an unexpected event in young subjects. The misjudgment of the pathophysiological mechanism of syncopal episodes may lead, on one hand, to overlook the risk of sudden death and, on the other, to pursue inappropriate therapeutic measures. The application of a tailored diagnostic work-up based on currently available guidelines may be useful to overcome the clinical and therapeutic dilemma.
Abstract: This article describes a case of cardiac resynchronization therapy (CRT) performed with dual site left ventricular pacing. The main clinical and functional long-term results are in agreement with the most recent data regarding traditional CRT. Furthermore, this innovative pacing modality allowed optimal inter- and intraventricular resynchronization.
Abstract: The short-term prognosis of advanced refractory heart failure is extremely poor and closely correlated with progressive left ventricular dysfunction. The identification of the negative effects of conduction delay on cardiac performance, observed in almost 50% of heart failure patients, disclosed a new research field addressing the correction of electrical abnormalities in order to achieve an improvement in myocardial function. Biventricular stimulation, or cardiac resynchronization therapy, corrects the atrioventricular, inter- and intraventricular mechanical asynchrony and, to date, is indicated (class IIA, level of evidence A) for patients with NYHA class III-IV refractory heart failure regardless of its etiology, QRS interval > or = 130 ms, left ventricular end-diastolic diameter > or = 55 mm, and ejection fraction < or = 35%. To date, the completed trials demonstrated in patients undergoing biventricular pacing a significant improvement in left ventricular performance, quality of life and NYHA class with no significant effects on total mortality. The identification of non-responders (approximately 20-30% of the patient population in completed trials) represents an unresolved issue of cardiac resynchronization therapy. Tissue Doppler imaging evaluation of left ventricular dyssynchrony, which is being addressed by non-randomized prospective studies, should drastically decrease the percentage of these patients.
Abstract: BACKGROUND: Recent studies have identified a direct link between the ionic mechanisms responsible for the electrocardiographic (ECG) pattern of the Brugada syndrome (BS) and the in vitro experimental temperature, pointing to the possibility that some BS patients may display the ECG phenotype only during a febrile state, being in this setting at risk of lethal arrhythmias. CASE REPORT: A 53-year-old man referred to the emergency room for abdominal pain and fever. The ECG showed dome-shaped ST-segment elevation in V1-V3, as in the typical BS. The personal and family history were unremarkable for syncope and sudden death and physical, laboratory and ultrasound examinations were negative. On day 3, at normal body temperature, the patient's ECG returned to normal and the ECG abnormalities were later reproduced with intravenous flecainide. The patient refused the implantation of a loop recorder and was discharged after 6 days. He has remained asymptomatic during 2 years of follow-up. CONCLUSIONS: The typical ECG phenotype of BS disclosed by a febrile illness confirms the in vitro experimental data that previously established a correlation between ECG pattern of BS and temperature variations. The clinical and therapeutic implications of these findings are discussed.
Abstract: OBJECTIVES: The aim of the study was to evaluate the effectiveness of cardiac resynchronization therapy (CRT) in patients with refractory heart failure (HF) and incomplete left bundle branch block ("narrow" QRS), together with echocardiographic evidence of interventricular and intraventricular asynchrony. BACKGROUND: Cardiac resynchronization therapy has been proven effective in patients with HF and wide QRS by ameliorating contraction asynchrony. METHODS: Fifty-two patients with severe HF received biventricular pacing. The patients were eligible in the presence of echocardiographic evidence of interventricular and intraventricular asynchrony, regardless of QRS duration. The patient population was divided into group 1 (n = 38), with a QRS duration >120 ms, and group 2 (n = 14), with a QRS duration < or =120 ms. RESULTS: The baseline parameters considered in the study were similar in both groups. At follow-up, CRT determined narrowing of the QRS interval in the entire population and in group 1 (p < 0.001), whereas a small increase in QRS duration was observed in group 2 (p = NS); in all patients and within groups, we observed improvement of New York Heart Association functional class (p < 0.001 in all), left ventricular ejection fraction (p < 0.001 in all), left ventricular end-diastolic and end-systolic diameter (p < 0.05 within groups), mitral regurgitation area (p < 0.001 in all), interventricular delay (p < 0.001 in all), and deceleration time (group 1: p < 0.001, group 2: p < 0.05), with no significant difference between groups. The 6-min walking test improved in both groups (group 1: p < 0.001; group 2: p < 0.01). CONCLUSIONS: Cardiac resynchronization therapy determined clinical and functional benefit that was similar in patients with wide or "narrow" QRS. Cardiac resynchronization therapy may be helpful in patients with echocardiographic evidence of interventricular and intraventricular asynchrony and incomplete left bundle branch block.
Abstract: The evaluation of left ventricular ejection fraction (LVEF) may be troublesome in difficult clinical settings in patients with coronary artery disease (CAD). The aim of this study was to compare 2 simple geometrical and nongeometrical methods of LVEF evaluation that could overcome the typical technical limitations of ultrasound examination. The authors studied 26 patients with proven CAD (63+/-10 years) who underwent left ventricular (LV) catheterization and coronary angiography during the hospital stay. A complete 2D-Doppler echocardiography was performed and LVEF was evaluated with the formula by Wyatt (W-LVEF), which relates the left ventricle to a biplane ellipsoidal figure, and by the myocardial performance index (MPI) formula (MPI-LVEF), MPI being an index of systodiastolic function. Mean MPI-LVEF was 41+/-8% and was significantly lower with respect to contrast angiography (52+/-14%, p = 0.0003) and to W-LVEF (49+/-13%, p = 0.0009). There was no statistically significant correlation between MPI-LVEF and geometric (either angiographic or ultrasound) LVEF. Bland-Altman analysis showed lack of agreement between MPI-LVEF and any other method evaluated in the study. MPI-LVEF may not be reliable and accurate for the evaluation of systolic function in patients with CAD. Nonetheless, the evaluation of global LV function by means of MPI may represent a valuable and affordable alternative to expensive and time-consuming methods, especially in the presence of difficult technical settings.
Abstract: BACKGROUND: The issue of DDD pacing as a therapeutic option for patients with obstructive hypertrophic cardiomyopathy is still under debate. Moreover, some authors stress the concept of the placebo effect of electrical therapy in this particular setting. METHODS: We retrospectively evaluated 8 symptomatic patients with obstructive hypertrophic cardiomyopathy despite medical therapy, who underwent DDD pacemaker implantation as an adjunctive therapeutic strategy. All patients were evaluated with a two-dimensional/Doppler echocardiogram at baseline, shortly after the beginning of DDD pacing and at follow-up. In 3 patients dobutamine stimulation was necessary to elicit the intraventricular gradient. RESULTS: At follow-up (21 +/- 19 months, range 1-54 months) the peak gradient declined from 86 +/- 27 to 34 +/- 27 mmHg (55.2%). In 4 patients the peak gradient sharply declined after pacemaker implantation with active pacing and remained stable throughout the follow-up. In 2 patients we noted a continuous reduction in the peak gradient during the follow-up, while in 2 patients it returned to baseline values after 1 year and 1 month, respectively, despite an early reduction with DDD pacing. All patients experienced symptomatic amelioration throughout the follow-up. Two patients developed angina at the end of our observation together with an increase in the peak gradient. CONCLUSIONS: We believe that DDD pacing may be considered as a practical therapeutic option for patients with obstructive hypertrophic cardiomyopathy who would otherwise be regarded as candidates for surgery.
Abstract: BACKGROUND: It is not infrequent to observe a peculiar intraventricular relaxation flow (IRF) pattern during the isovolumic relaxation time (IRT), especially in patients (pts) with left ventricular hypertrophy (LVH). This is even more likely in pts with hypertrophic obstructive cardiomyopathy and in VVI-paced pts. Despite these observations, the prevalence and clinical relevance of this finding have not been evaluated thoroughly and systematically in a consecutive series of patients. METHODS: Ninety-two consecutive pts underwent a conventional Doppler echo study for the evaluation of systolic and diastolic function (fractional shortening, EF, E and A wave velocity, duration and ratio, and IRT). of these, 42 pts had LVH, 14 had mitral regurgitation (MR) with depressed EF, 8 had CAD with depressed EF and 28 were normal subjects. IF was searched for during the evaluation of IRT and its duration, velocity and integral were measured when noted. RESULTS: Fifty-six patients (61%) showed an IRF at Doppler examination. Of these, fifteen were normal subjects (53%) and 34 (81%, p = 0.03 vs normal) were hypertensive pts. Among pts with depressed EF, only two of 14 with MR and 5 of 8 with no MR showed an IRF (14 vs 62%; p = 0.032). When evaluating LV function, we observed that pts with an IRF had a larger atrial filling fraction, a longer isovolumic relaxation time and a higher ejection fraction with respect to pts with no IRF (respectively, 40 +/- 13% vs 30 +/- 13%, p = 0.005; 108 +/- 23 ms vs 77 +/- 22 ms, p = 0.0001; 70 +/- 14% vs 61 +/- 16%, p = 0.01). CONCLUSIONS: Our data confirm that IRF may be observed in healthy subjects and may be due to an asynchronous relaxation of the LV during IRT, in consideration of a higher prevalence of a greater atrial filling fraction in pts with IF as compared to those in whom this Doppler signal is absent. Moreover, IRF is more frequent in pts with LVH and is rare in pts with MR (predominantly due to a very short isovolumic relaxation time).
Abstract: The results of anemia correction by recombinant human erythropoietin (rHuEPO) therapy with regard to cardiac function and left ventricular hypertrophy in dialysis patients are controversially discussed. The aim of the study was to assess the effects of therapy rHuEPO on cardiac morphology and function in dialysis patients. We studied 11 clinically stable hemodialysis patients with severe renal anemia (hematocrit <27%) and increased left ventricular mass index (LVMi) with no history of coronary or valvular heart disease, systemic disease, severe hyperparathyroidism, hypertension stage 2 or higher, transfusion-dependent anemia, and concurrent rHuEPO treatment. The patients were treated with rHuEPO administered subcutaneously once or twice weekly at a mean dose of 80 +/- 31 IU/kg week until the hematocrit was >30% and underwent a complete Doppler echocardiographic study at baseline and at follow-up (after 12.2 +/- 2.9 months). At follow-up, ejection fraction and fractional shortening significantly increased from 62.7 +/- 13.8 to 67.8 +/- 9. 7% (p < 0.05) and from 35.5 +/- 9.8 to 39.4 +/- 7.1% (p < 0.05), respectively, whereas mean velocity of circumferential fiber shortening demonstrated a trend towards amelioration from 1.18 +/- 0. 23 to 1.27 +/- 0.27 circ/s (n.s.). LVMi and morphological data remained unchanged throughout the study. Nevertheless, LVMi changes showed two different behaviors with respect to baseline values: in 6 patients with higher baseline values, LVMi decreased from 229 +/- 36 to 191 +/- 45 g/m2 (p < 0.05), while it worsened in 5 patients with less marked LVMi, increasing from 141 +/- 32 to 186 +/- 40 g/m2 (p < 0.05). Our data demonstrate that partial correction of renal anemia with rHuEPO therapy seems to improve cardiac performance and to induce a regression of left ventricular hypertrophy, particularly in patients with greater baseline hypertrophy, ultimately confirming the multifactorial pathogenesis of left ventricular hypertrophy.
Abstract: BACKGROUND: The aim of this study was to validate a new diagnostic tool, nitrate echocardiography (NE), for the identification of viable noncontracting myocardium in patients with a history of prior myocardial infarction (MI). Nitroglycerin (NTG) may be useful for this purpose for its peculiar pharmacodynamic action and may represent an option other than dobutamine echocardiography for the detection of hibernating segments in the presence of severely reduced coronary reserve. METHODS: Twenty selected patients (pts) with an old MI were studied with NE and planar thallium scintigraphy with reinjection. NE was performed by administering i.v. NTG starting at 0.4 mcg/kg/minute with equal increments every five minutes up to 2 mcg/kg/minute or to early interruption of the test (decrease of systolic blood pressure > or = 20% or improvement of previously akinetic segments). Left ventricular wall motion was analyzed by dividing the left ventricle (LV) into 16 segments, and a wall motion score index (WMSI) was calculated. Thallium images were obtained at peak exercise, at four hours, and after reinjection. Myocardial viability was defined as an improvement in thallium uptake after reinjection in fixed defects. RESULTS: Basal echo demonstrated 74 akinetic segments; of these 21 (28%, 11 pts) showed improved contractility during NTG infusion at a mean dose of 0.87 +/-0.33 mcg/kg/minute. WMSI decreased from 1.69 +/- 0.29 to 1.46 +/- 0.31 (P = .001). The only hemodynamic response was a drop in systolic blood pressure (136 mmHg to 124; P = .02). Thallium studies showed 29 segments with a four-hour reversible defect and 79 segments with a four-hour fixed defect; of the latter, 14 regions demonstrated improvement in tracer uptake after reinjection (17.7%; 10 pts). Nine pts had a positive echo and thallium study, while 8 showed no improvement either during NE or after thallium reinjection. Two pts had a false-positive nitrate echocardiogram. Therefore, according to an echo/thallium study match, sensitivity, specificity, and accuracy are 90%, 80%, 85%, respectively. CONCLUSION: NE is a reliable and low-cost method for the detection of viable noncontracting myocardium in selected patients with CAD but needs further validation for widespread application.
Abstract: The authors describe 3 cases of AMI occurring shortly after a negative bicycle ergometer stress test. These cases represent an unfortunate but extremely rare complication of a relatively safe diagnostic procedure. The authors also focus on the pathogenesis of the ischemic event, which may be attributed either to intraplaque hemorrhage or to platelet aggregation, both exercise-induced. The prevalence of AMI in this paper (0.06%) is similar to the data described in literature.
Abstract: A thirty-five-year-old horse trainer presented to the emergency room of the authors' hospital with minimal nonpenetrating chest injury after having been kicked by a horse. No rib or sternum fractures were demonstrated. The admission ECG demonstrated a right bundle branch block and a left anterior hemiblock that were previously absent. The authors are aware of only two similar reports, but analogous conduction disturbances might have been classified as intraventricular conduction defects. The rarity of these defects may be explained by the anatomic pathways of the bundle of His and its bifurcations.
Abstract: To assess the safety and diagnostic value of dobutamine stress-echocardiography (DSE), we studied 109 patients with ischemic heart disease: 78 patients with recent myocardial infarction, 31 patients with chest pain (14 patients without and 17 patients with previous myocardial infarction). Echocardiograms were recorded during dobutamine infusion in 5-minute stages to a maximum dose of 40 mcg/kg/min. The test was considered positive when dobutamine infusion induced a new wall motion abnormality. In 95 pts with recent or previous myocardial infarction new asynergies were classified as being within the infarct zone or outside the infarct zone based on the relation with vascular zones at coronary angiography. All patients underwent exercise stress test (EST) according to the Bruce protocol, and coronary angiography within one week from the test: significant coronary artery disease was defined as > or = 50% diameter stenosis for left main artery and > or = 70% for the other vessels. Five patients (4.6%) had ventricular arrhythmias and 3 patients (2.7%) had systolic blood pressure increase > or = 200 mm Hg in the first stage of DSE, without new wall motion abnormalities, and were excluded from diagnostic value analysis. DSE had a sensitivity of 86% vs 56% of EST (p < 0.001); both had specificity of 94% and positive prognostic value of 98%; diagnostic accuracy of DSE was 87% vs 62% of EST (p < 0.001); negative predictive value was not statistically different. Sensitivity of DSE in single vessel disease (78%) was significantly lower (p < 0.05) than sensitivity in multivessel disease (95%). Sensitivity of DSE in detecting multivessel disease in patients with myocardial infarction was 80% vs 55% of EST (p < 0.05); specificity 96% vs 63% (p < 0.001); diagnostic accuracy 90% vs 60% (p < 0.001); positive predictive value 93% vs 48% (p < 0.001); negative predictive value 89% vs 70% (p < 0.05). At the ischemic threshold, EST caused the achievement of higher heart rate and rate-pressure product; in patients with single vessel disease heart rate was higher than in multivessel disease (141 +/- 19 vs 117 +/- 21, p < 0.001). No differences were detected during DSE in heart rate, blood pressure, rate-pressure product; the dose of dobutamine infused at the ischemic threshold in patients with multivessel disease was significantly lower than in those with single vessel disease (15.2 +/- 5.4 vs 19.4 +/- 6 mcg/kg/min, p < 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)
Abstract: BACKGROUND. The aim of this study was to evaluate the ability of echocardiography, associated with nitroglycerin infusion, in the detection of myocardial viability in patients with recent infarction. PATIENTS AND METHODS. Fourteen patients (11 male, 3 female, mean age 59 +/- 8 years) with first acute myocardial infarction (12 Q wave, 2 non-Q wave) underwent predischarge (18 +/- 3 days) nitrate echocardiography. All patients underwent delayed planar thallium scintigraphy within four weeks from AMI. Nitrate echocardiography was performed with a nitroglycerin infusion starting from 0.4 mcg/Kg/min every 5 minutes up to 2.0 mcg/Kg/min; the test was terminated with an improvement of wall motion abnormalities or with a drop of systolic blood pressure > or = 20%. Wall motion abnormalities were evaluated with a 16-segment wall motion score index (WMSI). Thallium was performed after a symptom-limited exercise test, after 3 and 24 hours. The left ventricle was divided in 15 regions. Thallium was considered the gold standard for myocardial viability. RESULTS. Basal echo identified 59 dyssynergic segments: of these, 12 (20%-6 patients) showed improvement in contractility during nitrate echocardiography at a mean dose of 0.9 +/- 0.3 mcg/Kg/min. WMSI decreased from 1.42 +/- 0.22 to 1.27 +/- 0.13 (p = 0.022), with no significant change of haemodynamic data (mean systolic blood pressure from 125 to 112 mmHg; mean heart rate from 66 to 76 beats/min; mean rate/pressure product from 8415 to 8848; all p = ns). Thallium scintigraphy showed 40 fixed defects (19%-7 patients) and 10 (4.7%-7 patients) late reversible defects. 20% of the 3-hour fixed defects improved at 24-hour imaging. 5/7 patients with echo improvement had 24-hour reversible defects, while 6/7 with no WMSI improvement had 24-hour fixed defects. Therefore, nitrate echocardiography demonstrated 71% sensitivity, 86% specificity, 83% positive predictive value, 75% negative predictive value and 78% accuracy. CONCLUSIONS. Nitrate echocardiography may be a feasible and low cost method in the detection of myocardial viability after myocardial infarction, but awaits further validation.
Abstract: Reconstruction surgery of the mitral valve has become an alternative to mitral replacement in patients with pure mitral regurgitation. Preoperative assessment of the anatomic and functional aspects of the valvular lesion is of the utmost importance in conservative surgery. Transesophageal echocardiography is a new approach to investigating the mitral valve, and our study was undertaken with the purpose of determining its importance in the exploration of mitral regurgitation of non-rheumatic origin. Subjects included were twenty patients with pure and isolated mitral regurgitation (MR): 14 males and 6 females with an average age of 47 +/- 13 years. All the patients underwent a first transesophageal 2D and color Doppler echocardiographic examination, and 5 of them underwent a second one during cardiovascular surgery. Mitral anulus diameter, mitral valve cordae tendinae status, valvular leaflet length and coaptation were examined and color Doppler regurgitation jet area was measured. Mitral anulus diameter was 40.2 +/- 8.06 mm (diastolic) and 41.9 +/- 8.53 mm (systolic) and was above the values considered to be normal. Anterior leaflet length was 30.8 +/- 3.12 mm and posterior leaflet length was 22.9 +/- 4.74 mm; regurgitation jet area was between 1.2 cm2 and 13.52 cm2 with an average of 5.44 cm2. In the group with MR of mixomatous origin, systolic anulus diameter showed a linear correlation with regurgitation jet area (r = 0.79). In the 6 patients who underwent cardiac catheterization, angiographic semiquantitative evaluation of the MR confirmed that based on color Doppler jet area. In all twenty patients transesophageal echocardiography enabled us to identify the mechanism responsible for mitral insufficiency.(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: Cardiovascular anomalies are found in 50% of the cases of Turner's and Noonan's syndromes-diseases with the same phenotype but with a different genotype. In the former, the most common congenital heart diseases are aortic coarctation (30%) and bicuspid aortic valve (34%), while in the latter they are pulmonary valvular stenosis (60%), interatrial septal defect (25%) and obstructive or non obstructive hypertrophic cardiomyopathy (17%). We have described two cases, respectively of Noonan's and Turner's syndrome. The prominent features of the first case are the transmission of the syndrome on the male line, since father and son--the latter being our patient--are affected with the same syndrome, and the occurrence of a non obstructive hypertrophic cardiomyopathy involving both the ventricles, a situation not yet described in Noonan's syndrome. A subvalvular membranous aortic stenosis has instead been found in our patient with Turner's syndrome: this cardiac anomaly has never been described within the aforementioned syndrome in medical literature.
