Right heart pressures in acute myocardial infarction.

Abstract

Serial right heart pressure measurements were made in 27 episodes of acute cardiac infarction. A raised pulmonary arterial systolic pressure was found during the 1st few days in 21 episodes. This pressure returned to normal at the end of a week in all but 3 who remained in chronic left ventricular failure. A parallel rise in right ventricular end-diastolic pressure was noted in most patients, which returned to normal synchronously with the pulmonary arterial systolic pressure. Radiological evidence of pulmonary edema was seen in 9 patients, in all of whom the pulmonary arterial pressure was raised on admission. These patients also had the greatest reduction in PaO2 [arterial O2 pressure]. in the recovery phase, the pulmonary arterial pressure fell to normal, followed by resolution of pulmonary edema, while the PaO2 did not rise to normal levels until several weeks later. The prognosis in patients with an initial rise in pulmonary arterial pressure was worse than in those in whom the pulmonary arterial pressure remained normal throughout the acute illness. Left heart failure occurs more commonly in acute cardiac infarction than might be expected on clinical grounds alone. The importance of meticulous treatment with bed-rest, O2, diuretics, prophylactic antibiotics, and breathing exercises in patients with pulmonary congestion and early pulmonary edema was suggested. The technique of the float right heart catheter facilitates careful monitoring of progress and response to treatment in these acutely ill patients.