Abstract

A PROSPECTIVE OBSERVATIONAL STUDY TO ASSESS QT INTERVAL PROLONGATION AND ASSOCIATED RISK FACTORS IN HOSPITALIZED PATIENTS ON CARDIOLOGY WARDS OF TERTIARY CARE HOSPITAL

Jashlyn Lijo J.*, Ajeena Anto, Poulston Femin, Mohanraj K. P., Selvabalambigai, Bivin Wilson

Abstract

Objective: Medical inpatients are at increased risk of QT interval prolongation due to multiple risk factors and QT prolonging drugs which lead to lethal form of arrhythmia, Torsades de pointes. This study aimed to identify the prevalence of risk factors of QT prolongation; QT prolonging medications; associated drug-drug interactions (QT-DDIs); their predictors. Methods: A prospective observational study including 190 patients was carried out in cardiology wards of tertiary hospital Coimbatore, Tamilnadu, India to identify the risk factors of QT interval prolongation, commonly used drug that causes QT interval prolongation, Drug-drug interaction that causes QT interval. QTc interval was calculated by Bazetts formula. QT-DDIs is identified using Lexicomp. Risk score interval was calculated by the score interval developed by James E Tisdale. Comparative analysis was performed with respect to various clinical characteristic by applying Chi-square test. Logistic regression analysis was performed to identify the predictors of QT interval prolongation. Results: Total 190 patients were included in the study, in which 35.26% were found to be normal, 13.15% were border line, 18.42% were prolonged and 33.15% were found to be highly abnormal. Significant difference was observed between the groups (normal Vs prolonged) with respect to age, all prescribed medication, QT drugs, number of risk factors, gender, QT-DDIs. Logistic regression analysis showed significant results of predictors, diuretics (p < 0.0001) and amiodarone (p <0.0001). Conclusion: A substantial number of patients in cardiology ward with QT prolongation. Proper monitoring are to be needed to minimize the associated risk in patients.

Keywords: QT prolongation -QT prolonging drugs-Risk score interval-QT prolonging-drug drug interaction.