Pulmonary hypertension associated with congestive heart failure carries a risk of right ventricular failure after cardiac transplantation. Few data, however, are available on the hemodynamic behavior of the pulmonary circulation in these patients. We therefore studied mean pulmonary artery pressure minus left atrial pressure (estimated by pulmonary artery occluded pressure) versus cardiac output relationships in 20 patients with congestive heart failure evaluated for orthotopic cardiac transplantation, and we repeated this study either within the first 3 days postoperatively (n = 10) or 1 month postoperatively (n = 11). Cardiac output was increased by physical exercise or (in the early postoperative period) by an infusion of dobutamine. Reversibility of pulmonary hypertension was tested by an infusion of prostaglandin E1. At preoperative evaluation, the extrapolated pressure intercept of pulmonary vascular pressure:flow plots was negative in 10 of the patients, suggesting active exercise-induced pulmonary vasoconstriction. In the other 10 patients, the extrapolated pressure intercept was positive, suggesting that an increased closing pressure contributed to pulmonary hypertension. However, transplantation was constantly associated with proportional decreases of pulmonary artery pressure and left atrial pressure. On the other hand, pulmonary vascular pressure:flow plots were displaced to equal or lower pressures and to higher flows by prostaglandin E1 before as well as after transplantation. We conclude that in patients with congestive heart failure evaluated for cardiac transplantation, an increased pulmonary venous pressure more than a reversible increase in closing pressure determines the severity of pulmonary hypertension.
Occupational and leisure time physical activity and conventional risk factors were determined in the Belgian Physical Fitness Study, a prospective study of 2,363 healthy male factory workers who were aged 40-55 years at entry in 1976-1978 and who were followed for five years. Physical fitness, defined as the interpolated physical working capacity at heart rate 150 beats per minute, was measured in 2,109 subjects. In this subgroup, there were 31 myocardial infarctions and sudden deaths. Smoking, physical fitness, and high density lipoprotein cholesterol (HDL cholesterol) were independent risk indicators for subsequent ischemic heart disease, while both physical activity scores were not. It is concluded that in this healthy, predominantly sedentary population, the fitness level, but not the physical activity pattern, is an independent protective factor against ischemic heart disease.
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