Etiology and Left Ventricular Function in Right Bundle Branch Block: A Prospective Observational Study

Right bundle branch block (RBBB) is a common ECG finding. It may be caused by coronary artery disease, dilated cardiomyopathy, chronic obstructive lung disease, or degenerative disease of the conduction system of the heart. The purpose of the study was to find out the etiology and left ventricular function in patients with RBBB coming to a tertiary care hospital.

All consecutive patients coming to our hospital on an outdoor or inpatient basis with ECG showing RBBB were studied. Detailed history and physical examination were done. All patients were subjected to echocardiography.

201 patients with RBBB were studied. Mean age was 61.01 ± 12.92 years. 157 were male (78.11%), and 44 (21.89%) were female. The most Common symptom was dyspnea in 81 patients (40.29%) and chest pain in 15 patients(7.46%). Four patients presented with syncope and were proved to have intermittent complete heart block. 95 persons (47.26%) with RBBB had no symptoms, 43 out of which had come for clearance for noncardiac surgery. On echocardiography, left ventricular hypertrophy was present in 32 patients (15.92%), regional wall motion abnormality in 45 patients (22.38%), and left ventricular global hypokinesia in 13 patients (6.46%). LV systolic dysfunction was present in 43 patients (21.39%), and 85 (42.28%) patients had a normal study.

The most common presentation in patients was dyspnea. About half of the patients were asymptomatic. Around 20% were detected to have RBBB when they came for clearance for noncardiac surgery. Common causes were coronary artery disease, dilated cardiomyopathy, and cor pulmonale.