Evaluation of Subclinical Left Ventricular Systolic Dysfunction By Global Longitudinal Strain Using 2D Speckle Tracking Echocardiography in Angina With Normal Epicardial Coronary Arteries

Abstract

Background: Global longitudinal strain (GLS), assessed by 2D speckle tracking echocardiography (2D-STE), may offer a valuable non-invasive method to assess subclinical left ventricular (LV) systolic dysfunction in patients with chest pain but normal epicardial coronary arteries. The primary objective of the study was to detect subclinical LV systolic dysfunction by GLS using 2D-STE in patients with angina with normal coronary arteries and conventional echocardiograms at baseline. Methods: This was a comparative case–control study that included patients with complaints of an ischaemic pattern of chest pain despite normal coronary arteries (cases) and healthy individuals (controls). Resting LV systolic function was assessed by transthoracic echocardiography and GLS using 2D-STE analysis. The results of all three planes in GLS (the apical four-chamber, two-chamber, and three-chamber views) were combined in a single ‘bull’s eye’ summary (agreeing with the standard 17-segment model), which presented the analysis of each segment along with a global peak systolic strain value for the LV. Results: The study included 120 participants (60 cases and 60 controls). The normal reference value of the mean GLS in the control group was −19.7 ± 1.84%. GLS assessed by 2D-STE was significantly impaired in patients with angina-like syndrome with normal epicardial coronary arteries (−18.78 ± 1.87 versus −19.7 ± 1.84%; p<0.007) compared with the control group despite preserved LV ejection fraction. In the case group, GLS reduced significantly in eight patients (13.3%) than control group. Conclusion: Patients with angina with normal epicardial coronary arteries are likely to have microvascular disease. GLS assessed by 2D-STE has the potential to improve the value of echocardiography in coronary microvascular disease detection. Despite normal LV ejection fraction, significant impairment of LV global longitudinal systolic function can differentiate a microvascular group of patients from others who have angina with normal coronaries.