Structural Heart Disease in Patients With Left Bundle Branch Block: State of Knowledge


1 Department of Cardiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, I.R.Iran

2 Rajaie Cardiovascular, Medical,and Research Center, Iran University of Medical Sciences, Tehran, I.R.Iran


Background: One common electrocardiographic abnormality every physician comes across frequently is left bundle branch block (LBBB), which is found usually in asymptomatic patients with some complaints of unknown significance. This study was conducted to find patterns of structural heart disease in patients with LBBB. Methods: This descriptive analytic cross-sectional study was conducted in Ekbatan Hospital in Hamadan over a period of 12 months. Symptomatic patients were included and were divided into 2 groups of patients with LBBB and patients without LBBB. All the patients underwent transthoracic echocardiography and coronary angiography, and the known coronary artery disease risk factors were evaluated. A P value below 0.05 was considered meaningful. Results: 80 patients enrolled in our study, those with LBBB were significantly older than the ones without LBBB (mean age = 71 y vs 62 y). The known coronary artery disease risk factors were more prevalent among the LBBB group (with P values of 0.002, .006, and 0.007 for diabetes mellitus, dyslipidemia, and hypertension—respectively). Echocardiographic abnormality, defined as left ventricular systolic dysfunction, was more prevalent in the LBBB group (just 3 patients with a normal left ventricular function in the LBBB group vs 13 patients in the non-LBBB group). Valvular heart disease was seen in 57.5% of the patients in the LBBB group and 17.5% of the patients in the non-LBBB group. Obstructive coronary artery disease was reported more frequently in the patients with LBBB. (Normal coronary artery disease was reported in 2 patients in the LBBB group and in 8 patients in the non-LBBB group.) Conclusions: There is a high likelihood of structural heart abnormalities in patients with LBBB, and this is a predictive finding even in asymptomatic patients. (Iranian Heart Journal 2017; 18(3):6-12)