[Successful cardiac resynchronization therapy in a patient with heart failure and ischemic mitral regurgitation: importance of septal flash].

We describe the case of a 76-year-old man with a history of ischemic heart disease and functional mitral regurgitation who over the previous six months had experienced worsening of functional class (NYHA III/IV) under optimal medical therapy, without ischemic symptoms and with negative ischemic tests. Mitral valve annuloplasty was considered. As the patient presented left bundle branch block on the surface ECG, cardiac resynchronization therapy (CRT) was also considered. There was, however, severe biventricular dysfunction and moderate to severe pulmonary hypertension, which are considered predictors of non-response to CRT. On echocardiographic evaluation of mechanical dyssynchrony by two-dimensional strain (2DS), spectral Doppler and color tissue Doppler imaging (TDI)/tissue synchronization imaging (TSI), we observed absence of atrioventricular dyssynchrony and presence of interventricular dyssynchrony, with inconclusive intraventricular longitudinal dyssynchrony, but with marked intraventricular radial dyssynchrony. The latter, immediately observed on the two-dimensional image, and termed multiphasic septal motion or septal flash, was characterized and quantified with 2DS. In our experience, the presence of such septal motion, for which the substrate is predominantly radial dyssynchrony, is a predictor of CRT response. Weighing the risks and benefits of mitral valve annuloplasty without associated revascularization versus CRT, we opted for the latter. Marked improvement in clinical and echocardiographic parameters was observed, compatible with the current criteria for "responder". The improvement began one month after implantation and continued throughout two-year follow-up. In this case, detailed echocardiographic study of mechanical synchrony enabled the most appropriate and effective therapeutic strategy to be chosen.