Concurrent left and right ventricular hypertrophy in dog models of right ventricular overload

In two pressure and volume overload models of canine right ventricular hypertrophy, we have demonstrated significant hypertrophy of both the left and the right ventricles. The extent of hypertrophy was correlated positively to the extent of the increase in plasma epinephrine in both volume and pressure overload models. Attenuation or ablation of plasma epinephrine through the administration of propranolol, a β-adrenergic blocker, or by denervation of the adrenal medulla prevented the hypertrophy process. No hemodynamic parameter was altered consistently in a parallel manner to hypertrophy. This is the first report of concurrent right and left ventricular hypertrophy in response to pressure or volume overload of the right ventricle. These studies further implicate epinephrine as a major trophic hormone of the heart.