A subset of children and adults with Wolff-Parkinson-White (WPW) syndrome develop dilated cardiomyopathy (DCM). Although DCM may occur in symptomatic WPW patients with sustained tachyarrhythmias, emerging evidence suggests that significant left ventricular dysfunction may arise in WPW in the absence of incessant tachyarrhythmias. An invariable electrophysiological feature in this non-tachyarrhy...

BACKGROUND The power of echocardiographic dyssynchrony indices to predict response to cardiac resynchronization therapy (CRT) appears to vary between indices and between studies. We investigated whether the variability of predictive power between the dyssynchrony indices can be explained by differences in their operational definitions. METHODS AND RESULTS In 132 CRT-candidates (left ventricul...

Background Single ventricle (SV) physiology consists of a single pumping chamber that provides both systemic and pulmonary blood flow. The typical quantitative measurements of ventricular function (i.e. ejection fraction) cannot be accurately applied to single ventricles due to abnormal ventricular morphology. Cardiac Magnetic Resonance (CMR) has become a leading diagnostic tool in the assessme...

AIMS To investigate whether biventricular (BIV) pacing preserves left ventricular ejection fraction (LVEF) and reduces LV dyssynchrony when compared with standard dual-chamber right ventricular (RV) pacing in consecutive patients with high-grade atrioventricular block during 3 years of pacing. METHODS AND RESULTS Fifty patients were randomized to RV pacing or BIV pacing. LVEF was measured usi...

Cardiac resynchronization therapy (CRT) has emerged as an important method to treat patient with symptomatic heart failure with evidence of intraventricular dyssynchrony. Tissue Doppler imaging by echocardiography has been shown to be an excellent tool for the assessment of mechanical left ventricular dyssynchrony and the selection of patients for CRT. However, there are some patients who do no...