The effects of pressure-induced cardiac hypertrophy on the functional capacity of the coronary circulation.

Pressure-induced cardiac hypertrophy has many effects on the functional capacity of the coronary circulation. Many studies have been performed in both animal and humans and the major findings are as follows: 1. Most types of myocardial hypertrophy are associated with the decrement in coronary vasodilator reserve; 2. The magnitude of the decrement in coronary reserve in myocardial hypertrophy is usually much more prominent in patients with myocardial hypertrophy than in animal models; 3. Left ventricular hypertrophy secondary to systemic hypertension is associated with altered autoregulation of myocardial perfusion; 4. The perfusion abnormalities associated with hypertension and left ventricular hypertrophy are affected by various factors such as age of onset, ventricular involvement, and the stimulus for hypertrophy; 5. Left ventricular hypertrophy secondary to renal hypertension markedly augments the adverse effects of coronary occlusion. In this setting, coronary occlusion is associated with a three-fold increase in the incidence of lethal ventricular arrhythmias and a 35% increase in infarct size. Thus, pressure-induced hypertrophy profoundly alters the coronary circulation.