A COMPARATIVE-STUDY OF THE EFFECT OF CORONARY-ARTERY DISEASE ON ASCENDING AND ABDOMINAL-AORTA DISTENSIBILITY AND PULSE-WAVE VELOCITY

The effect of coronary artery disease on aortic distensibility and pul se wave velocity was studied in 73 male normotensive patients, divided in two groups. Group A (n = 36) consisted of patients with normal cor onaries and one-vessel disease and Group B (n = 37) of patients with t wo- and three-vessel disease. Distensibility (10(-6) . cm2 . dyne-1) w as calculated from the equation: 2 x [(change in aortic diameter from systole to diastole) / (diastolic aortic diameter) x (pulse pressure)] . Aortic diameters were measured with two-dimensional guided M-mode ec hocardiography. For ascending aorta distensibility calculations, pulse pressure (PP) measured at brachial artery with sphygmomanometry (BrPP ) was employed. For abdominal aorta distensibility calculations, BrPP was corrected from the equation: corrected BrPP = 0.642 x BrPP + 42.54 (r = 0.9) obtained by comparing BrPP and abdominal aorta PP measured directly during cardiac catheterization. Results: 1) Ascending and abd ominal aorta distensibility were greater in Group A compared to Group B (2.732+/-0.92 vs 0.688+/-0.57, p<0.0001 and 2.098+/-0.65 vs 0.871+/- 0.64, p<0.0001 respectively). Moreover, ascending was greater than abd ominal aorta distensibility in Group A (p < 0.0001), while no signific ant difference between the two was observed in Group B and 2) Pulse wa ve velocity was inversely related to ascending and abdominal aorta dis tensibility (r = - 0.56 and r = - 0.5 respectively). Thus, high grade coronary atherosclerosis is associated with decreased distensibility a nd loss of elastic inhomogeneity of the aorta resulting in increased p ulse wave velocity.