Postsystolic index for distinguishing coronary artery disease in left bundle branch block.

Abstract

Left bundle branch block (LBBB) is associated with a high risk of death, particularly from ventricular tachyarrhythmia and myocardial infarction. It is difficult to clinically differentiate between ischemic and nonischemic LBBB. In this study, we investigated whether advanced echocardiographic variables, such as strain delay index (SDI) and postsystolic index (PSI), can be used to distinguish coronary artery disease (CAD) in patients with LBBB. Our study included 102 patients with LBBB. All patients underwent echocardiography. The left ventricular ejection fraction (LVEF), left ventricular mass, PSI, SDI, global longitudinal strain (GLS), and time-to-peak longitudinal strain were then calculated. Coronary angiography was performed, and the patients were divided into groups with significant CAD and without significant CAD. Patients in the group with significant CAD were older than the patients in the group without significant CAD. The group had a higher prevalence of diabetes mellitus, hypertension, hyperlipidemia, and family history of CAD than the group without significant CAD. The group with significant CAD also had lower LVEF and GLS than the group without significant CAD. The group without significant CAD showed a direct correlation between LVEF and SDI and an inverse correlation between LVEF and PSI: P value=0.040 and r=0.255, and P value=0.001 and r=-0.427, respectively. However, the group with significant CAD did not show any significant correlation between LVEF and SDI or PSI. Strain delay index and PSI may be useful markers in distinguishing CAD in patients with LBBB and preserved LVEF.