Non‐invasive measurement of the haemodynamic effects of inhaled salbutamol, intravenous L‐arginine and sublingual nitroglycerin

Abstract

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT• Haemodynamic effects of endothelial stimuli induced by salbutamol and L-arginine in humans have been previously studied predominantly at rest in selected vascular beds.• We studied the effects of salbutamol, L-arginine and nitroglycerin on cardiac and vascular function by continuous recording of pulse wave analysis and impedance cardiography both in the supine position and during passive head-up tilt. WHAT THIS STUDY ADDS• The divergent effects of the research drugs in supine position and during head-up tilt indicate that human haemodynamics should also be studied in the upright position.• Since inhaled salbutamol induced more pronounced changes in haemodynamics, it provides a clinically more applicable tool than infused L-arginine for the assessment of endothelial function in humans. AIMSTo examine the effects of salbutamol and L-arginine, two compounds acting largely on the endothelium, and the endothelium-independent agent nitroglycerin on blood pressure, arterial compliance, cardiac function and vascular resistance. METHODSContinuous radial pulse wave analysis, whole-body impedance cardiography, and plethysmographic blood pressure from fingers in the supine position and during head-up tilt were recorded in nine healthy subjects. Data were captured before and after L-arginine (10 mg mg -1 min -1 ) or saline infusion, salbutamol (400 mg) or placebo inhalation, and sublingual nitroglycerin (0.25 mg) or placebo resoriblet. RESULTSThe results of all measurements were comparable before drug administration. The effects of inhaled salbutamol were apparent in the supine position: systemic vascular resistance (-9.2 Ϯ 2.6%) and augmentation index (-4.0 Ϯ 1.5%) decreased, and heart rate (8.6 Ϯ 2.5%) and cardiac output (8.8 Ϯ 3.1%) increased. L-arginine had no clear effects on supine haemodynamics, but during head-up tilt blood pressure was moderately decreased and reduction in aortic reflection time prevented, indicating improved large arterial compliance. Nitroglycerin reduced supine vascular resistance (-6.7 Ϯ 1.8%) and augmentation index (-7.4 Ϯ 1.6%), and increased cardiac output (+9.2 Ϯ 2.7%). During head-up tilt, nitroglycerin increased cardiac output (+10.6 Ϯ 5.6%) and heart rate (+40 Ϯ 7.5%), decreased vascular resistance (-7.8 Ϯ 5.8%) and augmentation index (-18.7 Ϯ 3.2%), and prevented the decrease in aortic reflection time. CONCLUSIONSInhaled salbutamol predominantly changed supine haemodynamics, whereas the moderate effects of L-arginine were observed during the head-up tilt. In contrast, small doses of nitroglycerin induced major changes in haemodynamics both supine and during the head-up tilt. Altogether, these results emphasize the importance of haemodynamic measurements in both the supine and upright positions.

Cardiac and haemodynamic influence on carotid artery longitudinal wall motion

“…Sublingual NTG administration has also previously been shown to induce reductions in systemic vascular resistance and to increase cardiac output through elevations in heart rate in the supine position (Tahvanainen et al . , ). We observed reductions in end‐systolic, end‐diastolic and stroke volumes, which suggest reduced venous return and therefore reduced LV preload (Mason & Braunwald, ; Masuyama et al .…”

“…In comparison to the sympathetically mediated tests, NTG is a known exogenous donor of nitric oxide and is routinely used to assess endothelium-independent vasodilatory capacity. Sublingual NTG administration has also previously been shown to induce reductions in systemic vascular resistance and to increase cardiac output through elevations in heart rate in the supine position (Tahvanainen et al 2009(Tahvanainen et al , 2012. We observed reductions in end-systolic, end-diastolic and stroke volumes, which suggest reduced venous return and therefore reduced LV preload (Mason & Braunwald, 1965;Masuyama et al 2003;Niki et al 2005).…”

Value of nitroglycerin test in the diagnosis of heart failure in emergency department patients with undifferentiated dyspnea

“…In our study, more than 60% of patients without HF demonstrated a very small change of CO 24 . At higher doses, NTG is associated with dilation effect of the systemic arteries and arterioles, and this effect would increase CO 25 . The status of left ventricular function is another important factor determining the overall hemodynamic response to NTG.…”

Liquorice ingestion attenuates vasodilatation via exogenous nitric oxide donor but not via β2-adrenoceptor stimulation

“…This can probably be explained by the powerful vasodilatory effect of nitroglycerin, as AIx level is significantly influenced by systemic vascular resistance [28]. Corresponding to previous findings, the haemodynamic effects of salbutamol were more evident in the supine position, while those of sublingual nitroglycerin were accentuated in the upright position [22,51].…”