Comparisons of Myocardial Deformation Between Cases With Normal Coronary Arteries and Patients With Coronary Slow Flow

Background: Slow coronary flow (SCF) is a condition defined as the delayed passage of the contrast agent in the absence of angiographic coronary artery stenosis. Left ventricular (LV) systolic and diastolic dysfunction has been reported in patients with SCF, which can influence their functional capacity. This study compared myocardial deformation between cases with normal coronary arteries and patients with SCF. Methods: This cross-sectional comparative study included 32 patients with SCF and 32 controls with normal epicardial coronary arteries (NECA). After coronary angiography, echocardiography was done for all the participants and the results were compared between the groups. Results: A total of 64 patients were studied. The mean global longitudinal peak systolic strain (GLPS.Avg) was 16.85. SCF was significantly more frequent in the men than in the women (P < 0.05). Diabetes mellitus, systemic hypertension, a history of past or current smoking, and a family history of coronary artery disease (CAD) in the patients with SCF and dyslipidemia in the NECA group were more frequent, although these differences were not statistically significant. GLPS.Avg and global longitudinal peak systolic stress in the apical 4-chamber view (GLPS.A4C) in the patients with SCF were significantly lower than those in the NECA group. Global strain in the apical 2- and 3-chamber views (GLPS.A2C and GLPS.LAX), septal E, septal A, lateral E, lateral A, and right ventricular Sm (peak myocardial systolic velocity) were also nonsignificantly lower in the patients with SCF. Conclusions: Strain imaging using 2D echocardiography was abnormal in our patients with SCF, in comparison with the NECA group. These abnormalities may represent subtle systolic and/or diastolic dysfunction in patients suffering from SCF.