In patients with bundle branch block (BBB), the
intra-left ventricular conduction delay results in
inhomogeneous activation of different myocardial
segments, in particular in septal and lateral walls
where the septum is activated first followed by the
lateral wall, resulting in different workloads in those
segments. Recent data showed that Apical rockingas a surrogate of mechanical dyssynchrony- might
be better representative of true left bundle branch
block (LBBB) as compared to ECG.