RESUMO
Nitrates decrease portal pressure by decreasing portal venous inflow and resistance. We studied over 20 minutes the effect of 10 mg isosorbide dinitrate sublingual on intrasplenic pulp pressure, mean arterial pressure and heart rate, in 13 patients with cirrhotic or non-cirrhotic portal hypertension. The pulp pressure fell progressively over 20 minutes, from mean 43.6 +/- 2.4 (SEM) to 35.6 +/- 1.8 cm H2O (p less than 0.001). This was accompanied initially by a significant fall in mean arterial pressure (85.8 +/- 1.9 to 80.4 +/- 2.7 mmHg at 4 minutes; p less than 0.01) and rise in heart rate (92.5 +/- 5.0 to 102.6 +/- 5.9 per minute at 6 minutes; p less than 0.02), following which these parameters remained stable. One patient developed giddiness due to hypotension at 15 minutes. We conclude that sublingual isosorbide dinitrate decreases pulp pressure in cirrhotic and non-cirrhotic portal hypertensives, but this is initially accompanied by significant hemodynamic changes.