Early Hemodynamic Responses to Single Dose Intravenous Nitroglycerin: Time Course Relationships

Abstract

Balloon flotation catheters and thermodilution cardiac output measurements provide important information about the relationship of cardiac output to left ventricular filling pressure (pulmonary wedge pressure) in acutely ill cardiac patients. Mehta and Mehta [2] have reported the effect of intravenous nitroglycerin on this relationship in heart failure patients admitted to a cardiac care unit. In their studies, a continuous infusion of variable dose nitroglycerin was used (20–70 μg/min, mean 55 ± 7 μg/min). Cardiac output was measured by the thermodilution technique at control and after 15 min of drug infusion. Under these conditions, left ventricular filling pressure consistently fell in all patients, cardiac output was not significantly altered, heart rate increased and mean arterial pressure declined slightly. The sequence of events, in response to nitroglycerin, was not reported.