Long-QT syndrome: to be or not to be iatrogenesis – a case report

Abstract

Long-QT syndrome is a congenital or acquired disorder of the heart’s electrical activity, inducing delayed repolarization that can cause ventricular arrhythmias and sudden cardiac death. Acquired forms can occur as a result of various drugs and given the fact that most patients have multiple comorbidities, the risk of polymedication and iatrogenesis is increasingly high. We present the case of a 60-year-old female admitted to the Cardiology Department for an arrhythmic storm, associating QT interval prolongation. The patient had a known history of atrial fibrillation and was undergoing antiarrhythmic therapy with flecainide. The hypothesis of a drug-induced long-QT syndrome was raised. Multiple ventricular arrhythmias requiring defibrillation occurred and intubation with mechanical ventilation was needed, followed by temporary ventricular pacing. We decided the discontinuation of flecainide therapy but over the next days, the patient presented persistent QT interval prolongation, multiple recurrences of ventricular arrhythmias and recurrent paroxysmal atrial fibrillation. In this context, the initial hypothesis of a flecainide-induced long QT syndrome was invalidated and given the persistent QT interval prolongation (QTc > 480 ms); the hypothesis of a congenital long-QT syndrome was raised. An implantable cardioverter defibrillator implantation was performed. The ECG holter monitoring after implantation showed the disappearance of ventricular arrhythmias, with favorable clinical evolution.