Echocardiographic assessment of left ventricular dyssynchrony and correlation with QRS width in chronic heart failure.

BACKGROUND: Echocardiographic parameters of mechanical dyssynchrony may improve patients selection for cardiac resynchronisation therapy in chronic heart failure. AIM: This study aimed to define the prevalence of inter, intra and atrio-ventricular dyssynchrony in heart failure patients with different QRS duration and to evaluate inter and intra-observer variability in collecting different echocardiographic dyssynchony parameters. METHODS: Twenty patients with chronic heart failure of any origin, NYHA functional class II-III with LVEF < 40%, were evaluated by complete echocardiographic examination including tissue Doppler imaging (DTI) and Tissue Tracking. RESULTS: Three patients had an atrio-ventricular dyssynchrony with a mean left ventricular filling time to cardiac cycle of 33 +/- 5%. Six patients had an interventricular mechanical delay (IVMD) > or = 40 milliseconds, all of them had a QRS duration > or = 120 milliseconds. Overall, no statistically significant correlation was found between IVMD and QRS duration (r = 0.35, p = 0.4). The mean septal to posterior wall-motion delay (SPWMD) was 83 +/- 64 ms. 7 patients had SPWMD > or = 130 ms. The baseline QRS duration did not correlate with SPWMD (p = 0.7). The mean LV dyssynchrony determined by deltaS-peak was 74 +/- 42 ms. Seven patients had LV dyssynchrony. Linear regression did not demonstrate a relation between QRS width and intraventricular dyssynchrony (p = 0.34). There was no concordance between intra-ventricular spatial or longitudinal dyssynchrony determined by DTI method and by Tissue Tracking (p = 0.3 and 0.6 respectively). The intraobserver reproducibility of LVFT/RR, IVMD and deltaS-peak (ICC = 0.99, 0.98 and 0.99, respectively), as well as the interobserver reproducibility (ICC: 0.96, 0.94 and 0.92, respectively), were very high. However, we observed a high variability for SPWMD measure (ICC = 0.27, p = 0.31). CONCLUSION: Mechanical dyssynchrony did not correlate with QRS duration, despite the poor variability in collecting different echocardiographic parameters.

[Determination of mitral valve area in patients with mitral stenosis by the flow-convergence method: clinical application]. / Evaluation de la surface mitrale par la méthode de la zone de convergence dans le rétrécissement mitral: application clinique.

BACKGROUND: Classic echocardiographic methods to estimate mitral valve area (MVA) in the mitral stenosis (MS) has several limitations. Recently, the proximal isovelocity surface area (PISA) method has been shown to be accurate for calculating MVA. AIMS: This study sought to 1) compare the accuracy of the PISA method to planimetry and Doppler pressure half-time (PHT) methods for echocardiographic estimation of MVA and 2) to evaluate the effect of atrial fibrillation (AF) and significant mitral regurgitation (MR) on the accuracy of the PISA method. METHODS: In 35 patients with rheumatic mitral stenosis, the mitral valve areas were determined by two-dimensional echocardiographic planimetry, pressure half-time and proximal flow convergence region. 19 patients had atrial fibrillation and 15 had associated mitral insufficiency > or = 2. RESULTS: The correlaton between PISA and planimetry areas was significant (r=0.83, p<.001). The intraclass correlation coefficient was of 0.85 but with a large confidence interval (IC 95% [0,68-0,9]) explaining the significant underestimation of MVA by PISA method: 1,42 +/- 0,47 cm2 versus 1,56 +/- 0,41 cm2 respectively, (p<.001). There was no signicant difference between PISA and PHT areas : 1,42 +/- 0,47 cm2 versus 1,43 +/- 0,46 cm2. Underestimation of MVA par PISA method didn't have real clinical implication: the sensibility of diagnosing severe MS (MVA < or = 1.5 cm2) was 90% vith a negative predictive value of 83%. The correlation was good in patients with AF (r=0,84, p<.001) and with significant MR (r=0,83, p<.001). CONCLUSION: The PISA method may be considered as reliable alternative method for estimation of the MVA in MS. Its accuracy is good in AF and associated MR.