INTRODUCTION To study effects of various sites of right ventricular pacing lead implantation on left ventricular function by 2-dimensional (2D) speckle tracking for radial strain and LV dyssynchrony. METHODS This was retrospective prospective study. Fifteen patients each with right ventricular (RV) apical (RV apex and apical septum) and non-apical (mid septal and low right ventricular outflow...

AIMS To assess the value of mechanical dyssynchrony measured by equilibrium radionuclide angiography (ERNA) in predicting long-term outcome in cardiac resynchronization therapy (CRT) patients. METHODS AND RESULTS We reviewed 146 ERNA studies performed in heart failure patients between 2001 and 2011 at our institution. Long-term follow-up focused on death from any cause or heart transplantatio...

BACKGROUND We investigated diastolic mechanical dyssynchrony and its relation to clinical status in pediatric dilated cardiomyopathy (DCM). METHODS AND RESULTS We calculated a diastolic and systolic dyssynchrony index (standard deviation of time to peak tissue early diastolic/systolic velocity in 12 left ventricular segments) in 33 children with DCM and 46 control subjects. A threshold to dia...

INTRODUCTION Cardiac dyssynchrony causes disorganised cardiac contraction, delayed wall contraction and reduced pumping efficiency. We aimed to assess the prevalence of different types of dyssynchrony in patients with dilated cardiomyopathy (DCM), and to establish the correlation between atrio-ventricular block and atrio-ventricular dyssynchrony (AVD), and between impaired intra-ventricular con...

Cardiac dyssynchrony is divided into electrical dyssynchrony and mechanical dyssynchrony. Electrical dyssynchrony is associated with a prolonged conduction time in the ventricles resulting in a prolonged QRS duration [1]. Mechanical dyssynchrony presents the mechanical discoordination that is most often related to simultaneous contraction and stretch in different segments of the left ventricle ...

BACKGROUND Left ventricular (LV) dyssynchrony caused by premature ventricular contractions (PVCs) has been proposed as a mechanism of PVC-induced cardiomyopathy. We sought to understand the impact of different PVC locations and coupling intervals (prematurity) on LV regional mechanics and global function of the PVC beat itself. METHODS AND RESULTS Using our premature pacing algorithm, pentage...

Ventricular dyssynchrony is a disturbance of the normal, organized electromechanical coupling of the two ventricles. This condition has many causes, such as left bundle branch block, ventricular preexcitation, right ventricular pacing and right ventricular premature ventricular complexes (PVCs). Ventricular dyssynchrony has many adverse haemodynamic effects on the left ventricle and we wanted t...

Background Left ventricular (LV) mechanical dyssynchrony has been proposed as a parameter to select patients for cardiac resynchronization therapy (CRT) [Bax et al JACC 2005]. Several recent studies have shown that placing the LV pacing lead in the most delayed regions yields a better response to CRT [Ansalone et al JACC 2002]. However, most imaging-based methods assess global LV dyssynchrony p...

Morbidity and mortality rates are higher in patients with severe left ventricular (LV) systolic dysfunction and ECG-derived prolonged QRS interval than in those with normal QRS duration. QRS duration is currently used on the grounds that it reflects the presence of ventricular dyssynchrony. However, 30-40% of patients selected on the basis of a prolonged QRS do not receive benefit by cardiac re...

Background Pulmonary hypertension has been associated with right ventricular (RV) dyssynchrony. In patients with left side heart failure, treating left ventricular dyssynchrony has been shown to improve patient outcome. Previous studies have demonstrated that RV dyssynchrony was associated with RV dilation, interventricular septum diastolic flatterning and eccentric hypertrophy. We propose simp...