[A case of life-threatening ventricular arrhythmias probably due to psychotropic drugs]

We present a case provoked life-threatening ventricular arrhythmias probably due to psychotropic drugs. The patient was a 55-year-old man who had previously twice operations of aortic valve replacement (AVR). The signs of cardiac failure were recurrently appeared from the end of 1991, and he had received promethazine and sulpiride for his depressive state. From cardiac catheterization, we planned his third AVR. The electrocardiographic (ECG) QTc interval was prolonged to 0.48 seconds on this admission. In March 1992 syncopal attack appeared suddenly, and his monitor ECG revealed frequent polymorphous ventricular tachycardia (VT) and Torsade de Pointes (Tdp). These arrhythmias stopped by emergent cardiac pacing. After discontinuing these psychotropic drugs, no ventricular arrhythmias appeared. Since the patient complained severe insomnia one month before operation, the diminished dose of psychotropic drugs (promethazine and levomepromazine) was readministered. Ten days after the operation, syncopal attack reappeared and his ECG recorded frequent VT and Tdp. During both syncopal attacks his serum potassium and magnesium were within normal limits. Two days later, he died from multi-organ failure. We concluded that life-threatening arrhythmias such as VT and Tdp might develop under the administration of mild psychotropic drugs (promethazine or levomepromazine), therefore, must better take a care of ECG changes in cases of using any psychotropic drugs.