Global and regional left ventricular contractility and coronary collaterals in stable ischemic heart disease

Global and regional left ventricular contractility were determined in 43 patients with stable ischemic heart disease utilizing echocardiography. Indices of contractility from multiple left ventricular segments were related to both the coronary obstructions and the presence of collateral supply. The impact of past myocardial infarction was taken into account. Global left ventricular contractility decreased with increasing degree of coronary obstructions (r = 0.69; p<0.001). In patients with collateral supply global contractility decreased with increasing degree of collateral supply (r = 0.59; p<0.001). Analysis of myocardial regions corresponding to the three major coronary arteries disclosed that past myocardial infarction resulted in decreased contraction indices (p<0.01‐0.001). This effect was related neither to the degree of obstruction once it exceeded 50% nor to the presence of collateral supply. A comparison of patients with single‐vessel disease, no prior infarction, and similar coronary obstructions revealed no differences in regional contractility whether collaterals were present or not. Regional contractility decreased in linear fashion in relation to increasing coronary obstructions (p<0.001). Collaterals became angiographically visible when the obstructions exceeded 75% but their appearance did not prevent the deterioration of contractility. It is concluded that collaterals are visualized by angiography when the coronary artery obstructions exceed 75%. Their presence does not, however, affect the global or regional decline in contractility associated with increasing severity of coronary artery obstructions. Moreover, they do not attenuate the decline in regional contractility associated with prior myocardial infarctions.