ABSTRACT
The changes of hemodynamics during bathing in patients with heart diseases were studied by invasive methods using a Swan-Ganz catheter and UCG. As a population, we have used 37 peatients with heart disease, ages 20 to 76 (average age 52.9). There were 26 cases of myocardial infarction, 5 cases of valvular disease, 5 cases of cardiomyo pathy, and 1 case of VSD. Bathing was done with tap water in a Hubbard tank, for 10 minutes at 40°C and for 5 minutes at 43°C in a supine position. Arterial pressure, heart rate, pulmonary arterial pressure, pulmonary wedge pressure, right atrial pressure, cardiac output, stroke volume and stroke work index were increased during bathing and decreased after bathing. Systemic vascular resistance and pulmonary arteriolar resistance were decreased during bathing. Their changes were marked with a bath of 40 to 43°C. These findings suggest that preload may be increased during bathing, and preload and afterload reduced after bathing. Hydrostatic pressure, autonomic nervous reflexes or endocrine system were thought of as possible reasons for the increase in pulmonary arterial pressure. Because pulmonary arterial pressure, pulmonary wedge pressure and right atrial pressure increased during bathing even though systemic vascular resistance and pulmonary arteriolar resistance decreased, increase in venous return was thought of as the biggest possibility. And because the patients with low cardiac function could not control the extent of increase in venous return, pulmonary arterial pressure increased markedly in patients with low cardiac function. The patients with myocardial infarction were classifed into a group showing elevation of pulmonary arterial pressure (PAP) and a group showing no elevation of PAP. The group showing elevation of PAP, compared with that without PAP elevation, included many cases of severe myocardial infarction deter-mined by Forrester's classification, Killip's classification and Peel's prognostic index at admission to hospital. Among these patients showing PAP elevation, there were more cases having low physical work capacity and low ejection fraction at discharge from hospital than among the patients without PAP elevation.