Cardiovascular effects of intracoronary atrial natriuretic peptide administration in man

An intracoronary drug infusion protocol was employed to assess the hemodynamic effects of synthetic atrial natriuretic peptide in normal subjects and to evaluate its actions on epicardial coronary artery dimensions. Increasing concentrations of synthetic atrial natriuretic peptide (1.75 to 84 micrograms/min) were infused at a constant rate directly into the left coronary artery in eight patients with normal left ventricular function and left coronary artery angiograms. Steady-state hemodynamic parameters and high-fidelity left ventricular pressure were recorded at each dose and indexes of left ventricular contractile and diastolic function were calculated. Coronary angiograms obtained at baseline and the highest dose of atrial natriuretic peptide were compared by quantitative image analysis techniques. At the highest dose administered, atrial natriuretic peptide decreased mean pulmonary artery pressure (-36%, p less than 0.01), pulmonary capillary wedge pressure (-80%, p less than 0.01), left ventricular end-diastolic pressure (-58%, p less than 0.01), left ventricular end-systolic pressure (-11%, p less than 0.01), mean arterial pressure (-8%, p less than 0.05), and pulmonary vascular resistance (-18%, p less than 0.05). Cardiac output and systemic vascular resistance were unchanged, and heart rate and peak positive dP/dt increased. Peak negative dP/dt and the time constant of early diastolic relaxation calculated by the logarithmic method both fell at the highest dose of atrial natriuretic peptide, although the time constants calculated by other less load-sensitive methods were unchanged. Doses of intracoronary atrial peptide that did not alter left ventricular load had no effect on indexes of left ventricular systolic or diastolic function despite a presumably high intramyocardial concentration of the agent.(ABSTRACT TRUNCATED AT 250 WORDS)