Qualitative and Quantitative Angiography Before and After Nitroglycerin

Abstract

Nitroglycerin (NTG) is known to lead to a decrease in pre- and afterload. Therefore it can be assumed that NTG might affect regional disorders of contraction of the left ventricle (LV) in patients with coronary heart disease (CHD). Thus, LV angiograms, performed in patients with and without CHD, before and after sublingual administration of 0.8 mg NTG, were analyzed for volumes, ejection fraction (EF), mean V_CF, and regional contraction patterns. Contraction abnormalities were studied with respect to (1) the location of particular myocardial segments relative to the three major coronary arteries, and (2) the severity of wall motion abnormalities; hypokinesia refers to a decrease of regional wall motion, akinesia to a lack of wall movement, and dyskinesia to a paradoxic outward movement during systole. To quantify the severity of regional abnormalities, the left ventricular long axis from the angle formed by the profile of the mitral valve and the posterior sinus of the aortic valve to the apex was divided at 25%, 50%, and 75% of its length by six perpendicular hemi-axes. The shortening of each hemi-axis was measured as percentage change from end-diastolic length.