Dyssynchronopathy Can be a Manifestation of Heritable Cardiomyopathy

eft bundle branch block (LBBB) is a risk factor for new-onset heart failure. In some patients (super responders) with LV dysfunction and LBBB, cardiac resynchronization therapy (CRT) leads to normalization of LV function. These data indicate that LBBB per se may cause LV remodeling/dysfunction, even up to the point of dilated cardiomyopathy (DCM) and heart failure. The American Heart Association has recognized LBBBinduced cardiomyopathy as a separate entity, 4 also designated by some as dyssynchronopathy. However, the pathophysiologic underpinnings of dyssynchronopathy have not been fully elucidated. In idiopathic DCM, familial occurrence is present in about 20% to 35% of cases, and a pathogenic variant in a cardiomyopathyassociated gene can be found in about 25% of DCM families. We investigated whether dyssynchronopathy can be a manifestation of heritable cardiomyopathy.