The effect of thrombolytic therapy on QT dispersion in acute myocardial infarction and its role in the prediction of reperfusion arrhythmias

Abstract

Purpose: We aimed to determine the effect of intravenous thrombolytic therapy on QT dispersion (QTd) and its role in the prediction of reperfusion arrhythmias.
Materials and Methods: Twenty patients with acute myocardial infarction (MI) were enrolled in the study. Measurements of QTd were carried out  prior to thrombolytic therapy and before discharge. The patients were examined for ventricular arrhythmias with 24‑h Holter electrocardiography monitoring after treatment and the relationship between ventricular arrhythmias and the QTd values in the early phase of MI was investigated.
Results: The values of QTd were significantly higher during the early phase of MI (60 ± 5.32 ms) than those in the late phase (53.35 ± 4.07 ms) (P = 0.032). There was no correlation between isolated, bigeminal, trigeminal and total ventricular premature beats, accelerated idioventricular rhythm (AIVR) with QTd values. However, the patients with sustained ventricular tachycardia (VT), prolonged VT and sustained AIVR had higher corrected QTd (92 ms^1/2, 97.8 ms^1/2, 81.7 ms^1/2, respectively) than the patients without these arrhythmias (74 ms^1/2, 56.3 ms^1/2, 58.28 ms^1/2,  respectively) (P = 0.022, 0.013, 0.018).
Conclusion: The values of QTd may be significantly reduced in the 1^st week of acute MI and measurement of QTd in the early phase of MI may have a correlation with the following reperfusion arrhythmias: Sustained VT, prolonged VT and AIVR.

Key words: Arrhythmia, myocardial infarction, QT dispersion, reperfusion, thrombolytic therapy