Notably, CRT almost completely reversed LV dysfunction in 6 of 8 patients. While such a remarkable improvement is rarely observed in patients with underlying structural damage, the curative effect of CRT demonstrated in isolated LBBB suggests that a similar mechanism may be active in many so called super-responders to CRT. In the MADIT-CRT trial, super-response was predicted by female sex, absence of prior myocardial infarction, QRS duration ≥150 ms, LBBB, body mass index <30 kg/m2, and a smaller left atrial volume index at baseline (17). These characteristics are similar to those of the subjects studied by Vaillant and coworkers, although the comparison is restricted by the small sample size. Nevertheless, assuming that CRT super-response may often occur in patients with isolated LBBB-induced dyssynchronopathy, it is likely that the prevalence of the latter condition among patients with dilated cardiomyopathy would be larger than the 1.6% reported in the present paper.