Existence of this disease is doubted by some, as few think that associatation of LBBB worsens the heart failure rather causing it. However some studies are pointing towards possibility of LBBB as etiology of cardiomyopathy, they are CRT super-responders with LBBB and animal experiments
In animal experiment it has been shown that, LBBB leads to mechanical dyssynchrony and leading LV dysfunction. Isolated LBB induces Interventricular septal hypoperfusion and progressive LV remodeling, decrease of LVEF and increase in LV dimension by 23% and 25% respectively.
LV dysfunction due to LBBB occurs due to
· Decrease in LV filling time
· Reduced contribution of septum for ejection
· Septal splash high amplitude IVS oscillations
article published in JACC it has shown reversal of heart failure and improvement in NYHA class increase in LVEF and also reduction of LV dimension with (super responder) CRT strengthens concept of LBBB induced cardiomyopathy