Human heart weight at high altitude

The weight of the right ventricle, left ventricle, and septum determined in 98 hearts of high altitude (12,300 feet) residents in Peru and in 86 hearts from sea level in the continental United States revealed that right ventricular hypertrophy is no greater at high altitude than at sea level in the stillborn-newborn infant heart. Right ventricular weight relative to total heart weight at high altitude exceeds that at sea level beginning about 30 days after birth and reaches a plateau at 56 days. Thereafter the degree of relative right ventricular hypertrophy changes only slightly through the adult years. No evidence was found of postnatal atrophy of the right ventricle either at sea level or high altitude nor of septal hypertrophy accompanying the right ventricular hypertrophy in high altitude. The degree of right ventricular hypertrophy was moderate and variable, and corresponded to the moderate, variable pulmonary hypertension previously demonstrated in high altitude residents. Since total heart weights are similar at high altitude and sea level and since high altitude subjects have a smaller body size, the heart weight/body weight ratio is probably greater in the high altitude subject.