14. Ventricular Fibrillation & Out-of-Hospital Cardiac Arrest: 14.7 Monitoring of QT Interval Prolongation in Patients Treated with Psychotropic Drugs

Psychopharmacs have the potential for QT interval prolongation but the frequency is not known

In patients hospitalised in the psychotic wards at the Department of Psychiatry and treated with antipsychotics and antidepressants with known or unexplored proarrhyhtmic potential 12-lead ECG were recorded (50 mm/s, 20 mm/mV), the QT interval was measured manually. QTc (Bazett correction) values of >0.44 sec in males and >0.46 sec in females were considered pathologic.

In 398 patients (134 females, 264 males, age 19-81 years) the total number of 457 ECGs was obtained. In 11 patients (2,8 %) QTc prolongation was observed. They were treated with 9 different drugs in monotherapy or combination. In none of the individuals the QTc value exceeded 0,48 sec.

The occurrence of abnormal QTc was significantly lower than in available literature. This could be related to the change of spectrum of antipsychotics used, the general trend to use lower doses of antipsychotics and increasing awareness about the drug-induced long QT syndrome.

The research is supported by grants IGA MH NA 7424-3 and NR/8063-3.