Usefulness of Overlapping of the E and A Waves of the Transmitral Flow as a Predictor of Responders to Cardiac Resynchronization Therapy

Atrioventricular (AV) dyssynchrony as well as ventricular-ventricular dyssynchrony plays an important role in the selection of candidates for cardiac resynchronization therapy (CRT), but no method for assessing the AV dyssynchrony has been established. The aim of this study was to investigate whether the degree of overlap of the E and A waves can predict response to CRT. The study subjects were 48 consecutive patients maintaining sinus rhythm and intrinsic AV conduction who underwent de novo dual-chamber CRT device implantation. CRT responders were defined as those with reductions in left ventricular end-systolic volume >15% at 6 months after CRT device implantations. Twenty-three patients (48%) were CRT responders. In a multivariate analysis, the overlap ratio of the E and A waves was the only independent predictor of response to CRT (odds ratio 1.03, 95% confidence interval 1.01 to 1.06, p = 0.01). Using a cut-off value of 33%, patients with overlap ratios of the E and A waves ≥33% had a significantly higher rate of response to CRT than those with ratios <33% (73% vs 27%, p = 0.002). In conclusion, the overlap ratio of the E and A waves before CRT device implantation may predict CRT response. This simple method may be helpful in evaluating dyssynchrony in patients, particularly with severe reduced left ventricular wall motion, because this method does not require any wall motion analysis.