Abstract: BACKGROUND: AV delay optimisation of biventricular pacing devices (cardiac resynchronisation therapy, CRT) is performed in trials and recommended by current guidelines. The Doppler echocardiographic iterative method is the most commonly recommended. Yet whether it can be executed reliably has never been tested formally. METHODS: 36 multinational specialists, familiar with using the echocardiographic iterative method of CRT optimisation, were shown 20-40 sets of transmitral Doppler traces at 6-8 AV settings and asked to select the optimal AV delay. Unknown to the specialists, some Doppler datasets appeared in duplicate, allowing assessment of both inter and intra-specialist interpretation. RESULTS: On the Kappa scale of agreement (1 = perfect agreement, 0 = chance alone), the agreement regarding optimal AV delay between specialists was poor (kappa=0.12±0.08). More importantly, agreement of specialists with themselves (i.e. viewing identical sets of traces, twice) was also poor, with Kappa=0.23±0.07 and mean absolute difference in optimum AV delay of 83ms between first and second viewing of the same traces. CONCLUSION: Iterative AV optimisation is not executed reliably by experts, even in an artificially simplified context where biological variability and variation in image acquisition are eliminated by use of identical traces. This cannot be blamed on insufficient skills of some experts or discordant methods of selecting the optimum, because operators also showed poor agreement with themselves when assessing the same trace. Instead, guidelines should retract any recommendation for this algorithm. Guideline-development processes might usefully begin with a rudimentary check on proposed algorithms, to establish at least minimal credibility.
Abstract: Transmitral pulse wave (PW) Doppler and annular tissue Doppler velocity measurements provide valuable diagnostic and prognostic information. However, they depend on an echocardiographer manually selecting positions to make the measurements. This is time-consuming and open to variability, especially by less experienced operators. We present a new, automated method to select consistent Doppler velocity sites to measure blood flow and muscle function.
Abstract: The process by which hepatitis C virus (HCV) enters cells and the reason for its hepatotropism remain obscure. Recently, the human immunodeficiency virus (HIV) binding lectins, DC-SIGN and DC-SIGNR, were shown to bind HCV. This article reports the expression of DC-SIGN and DC-SIGNR in HCV related liver disease and discusses whether these lectins, in particular DC-SIGNR, are responsible for HCV hepatotropism.
