Echocardiographic and Laboratory Findings in Coronary Slow Flow Phenomenon: cross-sectional study and review

Background and aims Coronary Slow flow is a phenomenon known as slow contrast flow that injected into the coronary arteries, without epicardial coronary arteries obstruction. The etiology of this disease is unknown. Endothelial dysfunction, known as a major cause of Coronary Slow flow syndrome (CSF). Methods: This study was cross-sectional (descriptive-analytic), which was performed on patients admitted to Seyedoshohada Heart Center, during one year (2018-2019). Considering the inclusion and exclusion criteria, patients were divided into two groups of normal coronary arteries (NECA, as the control group) and with the Coronary slow-flow (CSF). Results: In the present study, 124 patients were studied, 67.9% in the coronary slow flow group and 39.4% in the control group were men (p=0.001). In the coronary slow flow group, the mean age of patients was 52.18 {+/-} 12.55 years and in the control group, the mean age was 51.77 {+/-} 10.36 years (p=0.18). Mean BMI was significantly higher in the coronary slow flow group than the control group (p <0.05). The smoking, hypertension, and mean of Lymphocyte, Hb, Hct, Plt, MPV, RDW, BUN, FBS, TG, TC, LDL was significantly higher coronary slow flow group. Also, in echocardiography, the mean E wave, E/A ratio was significantly lower in the coronary slow flow group. The GLS was also significantly lower in the control group (p=0.01). LAD was the most common type of coronaries that involved with a slow flow. Conclusion: The results of this study showed that there was a significant increase in the rate of coronary slow flow in men, smokers, high BMI, and hypertensive patients. Also, platelet count, MPV, LDL, FBS, and some laboratory variables were high in patients with CSF. Mild diastolic dysfunction and low GLS were observed in this group of patients.