Context: Cardiovascular morbidity in psychiatric patients is disproportionately high. Arrythmogenic side-effects continue to be a concern for both typical and atypical antipsychotics. Some antipsychotics block cardiac potassium channels leading to QTc prolongation which is associated with arrhythmias, torsades de pointes and sudden cardiac death.

Objective: The aim of this study was to evaluate QTc interval prolongation in patients in a Forensic Rehabilitation Unit in UK and to look for possible correlation with antipsychotic medications. We also strove to check if ECG monitoring is being carried out as per the national guidelines(Maudsley guidelines, UK)

Methodology: The study comprises a cross sectional survey in which retrospective data was collected for 37 inpatients resident at St. Mary’s Hospital, an all-male secure rehabilitation service. The mean age of patients was 32 years.
All ECGs since their admission were examined by two doctors. The data collected includes QTc interval, other ECG changes, regularity of ECG monitoring, premorbid cardiovascular conditions and antipsychotics prescribed. Criteria prescribed by the Committee on Safety of Medicines and Medicines Control Agency (UK) were used.

Results: 93% of patients had QTc interval below 440 msec, 7% of patients had QTc interval between 440 and 500 msec. None of the patients had QTc more than 500 msec. 52% had other ECG abnormalities. 90% of patients were on atypical antipsychotics.
Regular ECG monitoring was being carried out in only 38% of all patients and 60% of patients had previous or current cardiac conditions.

Conclusions: Most of the patients surveyed had QTc intervals < 440msec for which no action was required. This may reflect the fact that most of them were prescribed atypical antipsychotics with minimal cardiotoxicity.
Clearly robust screening and monitoring procedures are required for early identification of cardiac problems in order to minimise risk of adverse cardiac events.