A Study on QT Dispersion before and after Thrombolysis in Acute Myocardial Infarction and its Prognostic Implications: A before and after Comparison Study

Abstract

Introduction: Acute myocardial infarction (AMI) stands as one of the most catastrophic occurrences in the progression of coronary artery disease. Measuring QT dispersion (QTd) is a fairly straightforward and noninvasive technique for predicting mortality in patients at high risk following a myocardial infarction (MI). Objective: To measure the QT, corrected QT interval (QTc), QTd, and corrected QT dispersion (QTcd) intervals before and after thrombolysis in patients with AMI and to determine prognostic implications of QTd in AMI. Materials and methods: This was a before and after comparison study conducted in the intensive care unit (ICU) of a tertiary care center in Central India. It was carried out in patients with AMI [ST-elevation myocardial infarction (STEMI)] who underwent thrombolysis in ICU. A total of 160 participants were enrolled over the time period of 24 months using the convenience sampling technique. Results: The most prevalent (68 patients) risk factor among MI patients was hypertension (HTN). QT parameters such as QT, QTd, and QTcd showed significant statistical variation of p-value < 0.0001 when compared at admission and after thrombolysis. No significant difference (p > 0.05) in QT parameters at admission (QTd, QTc, and QTcd) between anterior and inferior wall MI, except for QT interval (p = 0.0010). Among the 33 patients who experienced arrhythmia, ventricular tachycardia was the most prevalent arrhythmia in 22 patients (13.75%). There was a significant statistical correlation between the arrhythmic event and the outcome of the patient (p < 0.0001). Patients who died had higher QT parameter values at admission, and these remained on the higher side even after thrombolysis, whereas those who got discharged had lower QT parameter values at admission, and their values decreased after thrombolysis. Conclusion: Successful thrombolysis significantly decreases the QTd and thereby the arrhythmogenic potential, and thus can also be used as a reliable predictor of arrhythmia in patients of MI. How to cite this article: M A, Khandait H, Guralwar C, et al. A Study on QT Dispersion before and after Thrombolysis in Acute Myocardial Infarction and its Prognostic Implications: A before and after Comparison Study. J Assoc Physicians India 2023;71(10):14-18.