Cardiac Arrest with Clozapine and Olanzapine: Revealing Long QT Syndrome

The authors describe a rare case of "concealed" congenital Long QT Syndrome (LQTS) Type 3 in a patient with treatment resistant schizophrenia and no known personal or family history of cardiac disease. The patient in this Case Report had a hidden genetic condition revealed only following the essential administration of antipsychotics. As a result, this patient experienced an aborted cardiac arrest and a total of five episodes of ventricular tachycardia (VT) requiring cardioversion. Successful control of the VT occurred with an Automatic Internal Defibrillator (AID), judicious use of antipsychotic medications, and anti-arrhythmic medications. Risk factors for this rare anomaly include history of syncopy, unexplained ventricular arrhythmias, history of sudden cardiac death in a young family member, unusual reaction to initial dosages of medication known to prolong QTc which includes antipsychotics (particularly in combination). The work-up for those with risk factors would be a thorough family history of sudden cardiac death, baseline ECG, electrolytes, cardiology and electrophysiological consultation, and when indicated a genetic analysis for the Long QT Syndrome (LQTS). Monitoring includes ongoing patient assessment for symptoms, ECGs and electrolytes when indicated such as when medication and dosages are adjusted, AID interviewing, and cardiac and electrophysiological follow-up.