Electrical and mechanical dyssynchrony in patients with right bundle branch block

Excerpt

The prevalence of Right Bundle Branch Block (RBBB) as seen in a routine electrocardiogram is about 3 to 5 % of the general population. Patients with RBBB have specific signs of conduction delay seen on ECG with wide QRS (electrical dyssynchrony). RBBB may be associated with some anatomical heart disease and some with arrhythmias. Although the majority of patients with RBBB on ECG have fairly benign reputation, in some reports, RBBB is an independent predictor of cardiovascular mortality as well as all-cause mortality.1-3 Moreover, the new onset of RBBB predicts a higher rate of coronary artery disease, congestive heart failure, and cardiovascular mortality. When cardiac disease is present, the coexistence of RBBB suggests an advanced disease.1 One of the mechanisms for heart failure is that RBBB can cause left ventricular mechanical dyssynchrony (LVMD). The LVMD might be interventricular, intraventricular, or both. Several articles showed some correlation with electrical activation.4-7 Still, the relationship between electrical disturbance and LVMD is partly unclear among these patients with RBBB. …