Q-T interval prolongation in cirrhosis: Relationship and severity.

Background: Cirrhosis as the final stage of progressive fibrosis of liver can affect other organs such as lungs, kidneys and heart. "Cirrhotic cardiomyopathy" involves the electrophysiological abnormalities such as QT interval prolongation. We assessed correlation between corrected QT interval prolongation and severity of cirrhosis based on Child Classification in each ECG lead.

Methods: In this case-control study, the patients attending the outpatient clinic and inpatient department of internal medicine of Velayat Hospital in Qazvin were enrolled from September 2014 to July 2015. Total samples were 74 patients, half of which were used as controls. Cirrhosis severity was determined as per Child Classification. Both groups had Ca2+ , Mg2+ , K+ tested and 12- lead ECG was obtained. The QT interval was corrected by two different formulas: (1) QTc=QT/√RR (QTc1 ); (2) QTc=QT+1.75 (heart rate-60) (QTc2 ). To analyze the data, the software SPSS Version 16 and Mann-Whitney, Pearson's chisquare test-Kruskal-Wallis, and t-tests were used.

Results: The mean of QTc1 and QTc2 was longer in cirrhotics than the control group. There was a significant correlation between Child score and length of QTc1 in leads: III (p=0.032), AVL (p=0.041), V2 (p=0.049), V6 (p=0.015). There were significant differences in length of QTc1 in leads: V3 (p=0.031) and V6 (p=0.021); and QTc2 in lead V3 (p=0.039) between Child Classification.

Conclusions: Cirrhosis can induce QTc interval prolongation. Lead V3 has statistically significant correlation with the severity of cirrhosis based on child classification. We propose that QT interval prolongation be added as a criterion for prioritizing liver transplantation.