ECG monitoring should be considered in all patients prescribed antipsychotics before and after starting treatment to avert the risk of sudden cardiac death and ventricular arrhythmias, say Australian doctors.

The advice follows new findings by Taiwanese researchers that about one in eight adults taking quetiapine or haloperidol will develop severe QT prolongation (SQTP).

While the link between arrhythmias and antipsychotic use is known, the authors say their study is the first to identify the incidence, risk factors and outcomes for patients who develop SQTP.

“Clinicians should be vigilant for ventricular arrhythmias in quetiapine users who have risk factors for SQTP,” they wrote in Heart Rhythm.