Conduit arterial stiffness is associated with impaired left ventricular subendocardial function

Abstract

Longitudinal function of the left ventricle is governed by the subendocardial myocardial fibres, whereas radial function is due mainly to contraction of circumferential fibres, localised in the subepicardial layer of the myocardium.1 In patients with diabetes or hypertension the subendocardial fibres are more likely to be affected by microvascular ischaemia. This can be caused by structural changes in the coronary vasculature that reduce myocardial perfusion such as arterial wall thickening, decreased capillary density, and periarteriolar fibrosis, and by haemodynamic changes such as increased wall stress, and the microcirculatory effects of endothelial dysfunction.2 Since tissue Doppler echocardiography can now assess longitudinal and radial myocardial velocities separately, we tested the further hypothesis that subendocardial dysfunction is related to conduit arterial stiffness. ### Study group We studied 83 subjects (mean (SD) age 54 (12) years, 59 men), including 27 normal individuals and 56 patients with varying degrees of left ventricular (LV) dysfunction caused by diabetes (35), hypertension (17), and ischaemic dilated cardiomyopathy (4). We excluded patients not in sinus rhythm, or with ventricular aneurysm or severe regional wall motion abnormalities, mitral or aortic stenosis, or more than mild valvar regurgitation. Twenty nine patients were taking an angiotensin converting enzyme (ACE) inhibitor, 23 a diuretic, 8 a β blocker, 27 a statin, and 7 a calcium antagonist. The protocol was approved by the local research ethics committee, and …