Qtc Prolongation as Prognostic Marker in Organophosphate Poisoning

Abstract

Background

The long QT syndrome (LQTS) is a disorder of myocardial repolarization characterized by a prolonged QT interval on the electrocardiogram (ECG). This syndrome is associated with an increased risk of polymorphic ventricular tachycardia, a characteristic life-threatening cardiac arrhythmia also known as torsades de pointes. A rate related corrected QT interval (QTc) can be calculated as QT/√RR and normally is ≤0.44s. Some references given QTc upper normal limits as 0.43s in men and 0.45s in female. OP compound supposed to block K+ channel and Na+/Ca++ channel and hence causing prolongation of QT interval. As we know that prolongation of QT interval may precipitate polymorphic ventricular tachycardia and sudden cardiac death, so it become important in case of OP poisoning and related mortality. In this study, I calculated corrected QT interval in diagnosed cases of OP poisoning admitted at Bir Hospital and compared QTc among those with complications and without complication. I also tried to evaluate QTc as a predictor for duration of hospital stays, ICU admission, vasopressor and mechanical ventilation requirement, higher POP score and low GCS.