Effect of sublingual nitroglycerine on the compliance of large and small arteries

Abstract

Decreased arterial compliance is well recognized indicator of coronary artery disease. Nitroglycerine (NTG) is widely used in the setting of acute coronary syndrome. Although hemodynamic and pharmacological effects of NTG are well established its effect on the arterial compliance is not well studied. The purpose of the study was to examine effects of sublingual NTG on the small and large arterial compliances. The study group consisted of 14 healthy, normotensive individuals (6 females and 8 males). All were non-smokers. Mean age was 27±9 years. SBP, DBP, HR, large artery elasticity index (LAEI), small artery elasticity index (SAEI) and systemic vascular resistance (SVR) were obtained using HDI/Pulse wave CR-2000. The readings were made from the radial artery blood pressure waveform. Each subject rested in a supine position for 10 minutes before the baseline readings were taken. One sublingual NTG tablet (0.4 mg NTG) was administered. Readings were obtained at 1, 3, 5, 7, 10, 15, 20, 25 and 30 minutes after NTG. The results at baseline and postdrug are summarized in following table. Values are (Mean ± SD). *P< 0.05 from baseline. In conclusion, sublingual NTG has significant effects on BP, HR and systemic vascular resistance. These hemodynamic effects appeared a couple of minutes after the administration of NTG and persisted 10 to 30 minutes. Large arterial compliance increased briefly but remained unchanged. NTG markedly increased small arterial compliance and this effect persisted for 15 minutes. Thus, sublingual NTG significantly improves small arterial compliance and this may help coronary circulation in patients with coronary artery disease in addition to improve angina.