Improvement of left ventricular mechanical dyssynchrony associated with restoration of left ventricular function in a patient with fulminant myocarditis and complete left bundle branch block.

A 52-year-old woman with fulminant myocarditis had completed left bundle branch block (LBBB) and severely impaired left ventricular (LV) function. Marked mechanical dyssynchrony with septal-to-posterior delay of 389 ms was observed by echocardiographic speckle tracking radial strain imaging on admission, which was dramatically improved to 106 ms after total recovery from acute myocarditis with restoration of LV ejection fraction whereas her electrocardiogram still showed complete LBBB.