Work

Increased size of myocardial infarction in dogs with chronic hypertension and left ventricular hypertrophy.

Year: 1982

Type: article

Abstract: Impaired coronary reserve in animals and patients with left ventricular hypertrophy (LVH) might be expected to augment infarct size following coronary occlusion (CO).To test this hypothesis, the circumflex coronary artery was acutely occluded in 30 control dogs and in 28 renal hypertensive (HT)-LVH dogs during the conscious state.Hemodynamics and regional myocardial flow (microspheres) were measured.After 48 hours of CO, we assessed infarct size pathologically and area at risk by postmortem coronary angiography.Mean arterial pressure (130 ± 5 mm Hg) and LV:body weight ratio (6.1 ± 0.1 g/kg) in HT-LVH dogs were about 35% greater than in control dogs (P < 0.05).During the 48 hours following CO, mortality rate was markedly increased in HT-LVH (54%) compared to control (17%) (P< 0.01).We performed a linear regression analysis of the relationship between area at risk (AR; % of LV mass) and infarct size (IS; % of LV mass); control, IS = 1.20AR -25.6 (r = 0.96); HT-LVH, IS = 1.19AR -16.3* (r = 0.95) (*P< 0.05 vs. control).Although the slopes of these relationships were similar, the intercepts were different.Consequently, the minimal AR associated with infarction was 35% smaller in HT-LVH (15 ± 2% of LV mass) than in control (22 ± 1%), and over the entire range of AR, the IS was increased in HT-LVH.The distance between the lateral extent of infarct size and area at risk in different layers of LV was measured.The increase in infarct size in the HT-LVH group reflected primarily an increase in midwall layer infarction.Increase in collateral flow to the risk area was attenuated in HT-LVH.In conclusion, infarct size relative to the area at risk is increased significantly in HT-LVH.This interaction between LVH and myocardial ischemia may significantly influence the outcome of myocardial infarction in patients with hypertension and LVH.Circ Res 50: [55][56][57][58][59][60][61][62] 1982

Source: Circulation Research

DOI: 10.1161/01.res.50.1.55

Authors: S Koyanagi, C L Eastham, D G Harrison, M L Marcus

Language: English

Topic: Cardiac Ischemia and Reperfusion

Subfield: Pathology and Forensic Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: bronze

Funders: National Institutes of Health, National Heart, Lung, and Blood Institute

Awards: G1042820522, G320453980, G8145076150