The effect of coronary artery disease on aortic distensibility and pulse wave velocity was studied in 73 male normotensive patients, divided in two groups. Group A (n = 36) consisted of patients with normal coronaries and one-vessel disease and Group B (n = 37) of patients with two- and three-vessel disease. Distensibility (10(-6).cm2.dyne-1) was 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 echocardiography. 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 abdominal 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 abdominal aorta distensibility in Group A (p < 0.0001), while no significant difference between the two was observed in Group B and 2) Pulse wave velocity was inversely related to ascending and abdominal aorta distensibility (r = -0.56 and r = -0.5 respectively). Thus, high grade coronary atherosclerosis is associated with decreased distensibility and loss of elastic inhomogeneity of the aorta resulting in increased pulse wave velocity.