Aortic root distensibility in patients with coronary artery disease

ABSTRACT

An important determinant of myocardial performance, namely cardiac afterload is largely dependent upon aortic root distensibility [AD], peripheral arterial resistance and end systolic wall stress. The latter can be reliably measured by using m-mode and 2-D echo whereas AD used to be a neglected parameter. In patients with ischaemic heart disease, the question always arises whether AD could in a way or another predict coronary arterial pathology patients [34M, 10F, mean age 50 +/- 7.7yr] subjected to diagnostic coronary arteriography [CA] to rule out coronary artery disease [CAD]. Subjective and or objective evidence of ischaemia was present in 41pts and cardiac arrhythmias in 2 with associated risk factors including DM in 18, cholesterol >/= 200 and /or LDL >130mg/dl in 21pts and HTN in 17pts. Following clinical evaluation including 12 lead ECG, m-mode and 2-D echocardiography, all pts underwent diagnostic CA and were subjected to transoesophageal echocardiography [TEE] using phased array multiplane 32 elements transducer [5MHz] mounted on the tip of 100cm gastroscope with Acuson Sequoia C256 system. Transoesophageal [TEE] was done while the pts in the left lateral position. The studies were recorded on videotapes for off-lines analysis. Images of the aortic root were obtained in an angle of about 120 degrees. Aortic root was measured in systole [maximal diameter] and diastole [electrocardiographic Q-wave] 3cm from cusps insertion using the trailing edge-to-leading edge method. Measurements were taken in 3 cycles and the mean value was taken, with the difference in diameter delta d as a measurement of aortic root excursion, delta p as the pulse pressure, and d=diastolic aortic root diameter. AD was expressed as =2xdelta d / delta pxd. According to CA, pts were divided into those with diseased coronary arteries 74.4% and those with a normal CA 25.6%. Compared to the normal CA group, AD was insignificantly different from that into pts with diseased CA 23.9 vs 21.4, p value = 0.573. Patients were then stratified into two groups with an age of 50yrs, SBP of 130mmHg, DBF of 80mmHg, serum cholesterol >200 and /or LDL >/= 130mg/dl and presence of DM serving as arbitrary dividing limits