Protective effect of left ventricular hypertrophy in right coronary artery occlusions.

Abstract

To test the hypothesis that left ventricular hypertrophy (LVH) reduces the electrocardiographic and functional effects of right coronary artery occlusion. We analysed 215 patients (166 males and 49 women, age of 58.9 +/- 10.6 years), with occlusion of the right coronary artery without other associated lesions. There was no significant difference (p > 0.05) in age and gender distribution between the 78 patients with LVH (left ventricular mass > 100 g/m2) (Group A) when compared with the 137 patients without LVH (left ventricular mass < 100 g/m2) (Group B). The electrocardiographic finding of transmural necrosis was more often found in group B patients than in group A patients (56.9% and 30.8%, respectively; p < 0.05). The left ventricular function parameters of group A were better than those of group B: the ratio end-diastolic pressure/systolic pressure (EDP/SP) (A: 0.108 +/- 0.036; B: 0.121 +/- 0.050; p < 0.05); the end-diastolic volume index (A: 75.9 +/- 31.3 ml/m2; B: 88.0 +/- 31.0 ml/m2; p < 0.01); the end-systolic volume index (A: 16.0 +/- 10.0 ml/m2; B: 27.0 +/- 20.0 ml/m2; p < 0.001); the ejection fraction (A 78.6 +/- 10.8%; B 67.7 +/- 17.9%; p < 0.001); the anteroinferior shortening (A: 43.9 +/- 10.3%; B: 35.1 +/- 12.8%; p < 0.001). A higher degree of coronary tortuosity was observed in group A than in group B (78.2% and 24.1%; p < 0.001) and also a more frequent absent or minimal diaphragmatic hypokinetic area (A: 80.8%; B: 54.0%; p < 0.05). LVH reduces the effects of myocardial sequela and protects LV function when right coronary occlusion develops.