Clinical and Echocardiographic Characterization of Structural Heart Disease in Patients with Left Bundle Branch Block

Abstract

Background: Left bundle branch block (LBBB) is a notable electrocardiographic finding often associated with underlying structural heart disease (SHD). It may signify the presence of myocardial or valvular pathology, cardiomyopathy, or coronary artery disease (CAD). This study aimed to evaluate the prevalence of SHD among patients with LBBB and to compare the clinical and echocardiographic profiles between those with and without SHD. Study Design: Retrospective Observational Study Place and Duration of Study: Department of Cardiology, KIMSHEALTH, Trivandrum, from January 2019 and January 2024. Methods: We retrospectively analyzed 159 patients diagnosed with LBBB, including 96 males and 63 females, with a mean age of 67 ± 10 years. Clinical data were collected regarding the presence of hypertension, diabetes, and symptoms such as chest pain. Echocardiographic assessments were used to evaluate left ventricular systolic function and dimensions. Patients were divided into two groups: SHD and No SHD. Statistical analyses were conducted to identify significant differences in clinical and echocardiographic characteristics between groups. Approval for the study was obtained from the institutional ethics committee. Results: Of the 159 patients, 72.3% had evidence of SHD. A significantly higher proportion of males were observed in the SHD group compared to the No SHD group (64.3% vs. 40.9%, p = 0.006). Chest pain was more common in the SHD group (53.9% vs. 29.5%, p = 0.002), and a higher New York Heart Association (NYHA) functional class indicated poorer functional capacity (p < 0.001). Echocardiographic findings showed a lower mean ejection fraction (44.0 ± 8.0 vs. 61.7 ± 10.0, p < 0.001) and significantly larger left ventricular internal dimensions in diastole and systole in the SHD group. Among patients undergoing coronary angiography, the left anterior descending artery (LAD) was most frequently affected in single-vessel disease (49.1%), followed by the LCX (28.07%), RCA (17.54%), and LMCA (5.2%). Conclusion: LBBB is frequently associated with SHD, and its presence should prompt detailed cardiac evaluation. Marked differences in clinical symptoms and echocardiographic parameters support LBBB as a significant marker of underlying cardiac pathology.