An investigation of some morphometric parameters measured by echocardiography in coronary slow flow phenomenon

Objective: Although no coronary symptoms were observed in some of the patients admitted to clinics with complaint of chest pain, the delayed passage of contrast to the distal vessels in coronary angiography has been defined as "Coronary Slow Flow Phenomenon (CSFP)". Though the main patho-physiological reason has been mentioned as increased resistance in microvascular arterioles, endothelial and vasomotor dysfunctions and occlusive diseases, the exact pathogenesis of CSFP is still not clear. Intimal thickening, generalized calcification, luminal stenosis in the coronary arteries, left ventricular systolic and diastolic dysfunctions, aortic stiffness were reported in an important part of CSFP patients. The purpose of this study was to determine the anatomical characteristics of this disease by examining whether there are structural differences, through some morphometric measurements focused on the aorta and the left ventricle with echocardiography in CSFP cases. Materials and Methods: Sixty patients (30 female and 30 male) with CSFP in at least one coronary artery by selective coronary angiography, and 60 healthy persons with normal coronary artery anatomy and normal coronary flow were included in the study. The end-systolic and end-diastolic aortic root diameters, left ventricular end-systolic and end-diastolic diameters, the ascending aortic diameter, the aortic valve movement, the interventricular septum thickness and the ejection fraction were measured in all cases. The aortic stenosis and regurgitation were graded as mild, moderate or severe and recorded. All quantitative variables were statistically analyzed using Student's t test, while others were analyzed by chi-square test. Results: The ascending aortic and end-systolic aortic root diameters were significantly larger in male patients than those of controls (p<0,05). It was found that the ascending aortic diameter in the same way larger and the left ventricular end-systolic diameter was significantly narrower and the interventricular septum of female patients was thicker (p<0,05). It was observed in this examination -materialized without gender gap- that only the ascending aortic diameters of all patients were statistically larger relative to control values. No aortic stenosis was reported in any patient, while a mild aortic regurgitation of 16,7% were found in male patients and a mild aortic regurgitation of 40% and a moderate aortic regurgitation of 3.3% were observed in female patients. Conclusion: On the basis of the findings obtained in this study, it is concluded that the abnormal widening in the aortic root and ascending aorta may cause a slowdown in the coronary blood circulation, and therefore possibly lead to coronary slow flow phenomenon.