Global and Regional Left Ventricular Contractile Impairment in Patients with Wolff-Parkinson-White Syndrome

BACKGROUND To assess regional systolic function and global contractile function in patients with WPW Syndrome. METHOD Eleven cases with manifest Wolff-Parkinson-White (WPW) syndrome in sinus rhythm were compared to 11 age matched controls. 2D strain analysis was performed and peak segmental radial strain (pRS) values obtained from basal ventricular parasternal short-axis images (70 +/- 5 frames/sec) using a dedicated software package. Heterogeneity of radial strain pattern in six circumferential basal left ventricular segments was measured in terms of standard deviations of peak RS (SD(pRS)) or range (difference between maximum and minimum peak RS i.e. Range(pRS)). Spectral Doppler (continuous wave) measurements were acquired through the left ventricular outflow tract to determine Pre Ejection Period (PEP), Left Ventricular Ejection Time (LVET) and measures of left ventricular systolic performance. RESULTS LV segmental radial strain was profoundly heterogeneous in WPW cases in contrast to fairly homogenous strain pattern in normal subjects. Wide SD(pRS) values 17.5 +/- 8.9 vs 3.3 +/- 1.4, p<0.001 and Range(pRS) 42.7 +/- 20.8 vs.8.5 +/- 3.6 , p<0.001 were observed among WPW and healthy subjects respectively. PEP (132.4 +/- 14.7 vs 4.7 +/- 0.5ms, p<0.001) and corrected PEP (76.1 +/- 8.0 vs 2.7 +/- 0.4ms, p<0.001) were significantly longer in WPW patients compared to controls. The PEP/LVET ratio was also significantly greater in WPW cohort (0.49 +/- 0.04 vs. 0.28 +/- 0.05, p <0.001) suggesting global systolic dysfunction. CONCLUSIONS Patients with manifest preexcitation (predominantly those with right-sided pathways) have regional and global contractile dysfunction resulting from aberrant impulse propagation inherent to the preexcited state.