Effects of propranolol and nitrates on exercise capacity, respiratory minute volume and capillary oxygen saturation during exercise in cirrhotic patients with portal hypertension

A cross over study was performed in 16 cirrhotic patients with portal hypertension and oesophageal varices to assess the effects of propranolol and nitrates on the exercise capacity, respiratory minute volume and capillary oxygen saturation during exercise. All had normal peak expiratory flow rates, spirometry, chest X-ray, electrocardiography, ECHO cardiography, cardiac ejection fraction>55%, absent intra-pulmonary arterio-venous shunts (IPAVS) on contrast enhanced ECHO, and a haemoglobin>11 g/dl. Minute volume, capillary O 2 saturation and pulse rate, were measured during progressive exercise testing up to maximum exercise capacity. Testing was done on inclusion, after 1 month of treatment with propranolol (dose adequate for 25% reduction in resting pulse rate) and after another month of treatment with propranolol plus isosorbide dinitrate (ISDN). An age matched group of cirrhotics ( n=9) (with no evidence of portal hypertension and had normal cardio respiratory functions as defined above) acted as controls. We observed a significant reduction in the minute volume at maximum exercise after both modes of treatment when compared to the pre-treatment values and the values of controls. There was a non-significant increase in capillary oxygen saturation. None of them had a reduction in exercise capacity after treatment. In conclusion, treatment with propranolol or a combination of propranolol and a nitrate dose not seem to impair exercise performance in patients who have hepatic cirrhosis with portal hypertension.