Effect of Oral Propranolol on Prolonged QTc in ECG in Cirrhotic Patients

Abstract

Background: Prolongation of QT interval is one of the most important abnormalities in cardiovascular system of cirrhotic patients. The aim of this survey was determination of propranolol effect on frequency adjusted QT interval (QTc).

Materials and Methods: Thirty six cirrhotic patients (M/F=20/16, mean age:56 ± 3.8 years) and 40 healthy age and sex matched controls (M/F=25/15, mean age: 58 ± 2.4 years) were evaluated for blood pressure, heart rate and QTc before and 90 minutes after receiving 40 mg propranolol, orally.

Results: Prolonged QTc (more than 0.440 s1/2) was seen in 27 cirrhotic patients (75%) in contrast with to 2 (5%) ones in healthy control group (P‹0.001). In cirrhotic group, mean QTc before and after propranolol administration were 0.470 ± 0.024 s1/2 and 0.44 ± 0.008 s1/2, respectively (P‹0.001). In responder patients (those with 25% reduction in basal cardiac rate), mean QTc before and after propranolol administration were 0.482 ± 0.005 s1/2 and 0.430 ± 0.009 s1/2, respectively (P‹0.05). In non-responders, mean QTc before and after propranolol administration were 0.461±0.012 s1/2 and 0.453± 0.011s1/2, respectively (P›0.05).

Conclusion: Non-selective beta blockers (such as propranolol) reduce QTc in cirrhotic patients.The effect of propranolol on QTc was related to 25% decrease in heart rate.