The effects of nitroglycerin, norepinephrine and aminophylline on intrapulmonary arteriovenous anastomoses in healthy humans at rest

Abstract

We have investigated the effects of the intravenous infusion of nitroglycerin (NTG), norepinephrine (NE) and aminophylline (AMP) on the opening and recruitment of intrapulmonary arteriovenous anastomoses (IPAVA) in healthy humans at rest. In ten volunteers saline contrast echocardiography was performed during administration of two doses of the NTG (3μgkg(-1)min(-1) and 6μgkg(-1)min(-1)) and NE (0.1μgkg(-1)min(-1) and 0.25μgkg(-1)min(-1)) as well as 30min following the administration of AMP at rate of 6mgkg(-1). Echocardiography was used to assign bubble scores (0-5) based on the number and spatial distribution of bubbles in the left ventricle. Doppler ultrasound was used to estimate pulmonary artery systolic pressure. Using a Finometer the following hemodynamic parameters were assessed: heart rate, stroke volume, cardiac output, total peripheral resistance as well as systolic, diastolic and mean arterial pressure. The most important finding from the current study was that nitroglycerin, norepinephrine and aminophylline in the applied doses were not found to promote IPAVA opening in healthy humans at rest.

Keywords: Aminophylline; Cardiac output; IPAVA; Nitroglycerin; Norepinephrine; Pulmonary artery pressure.