Beta-agonist treatment during pregnancy may unmask the diagnosis of long QT syndrome. The QT prolongation can result in functional AV block. A history of seizure and/or sudden death in a family member should raise suspicion of ventricular tachycardia. More than one mutation may coexist. Refusal of beta-blocker therapy complicates risk stratification.
Keywords: Genetic; implantable cardioverter–defibrillator; long QT syndrome, pregnancy; premature ventricular complex; risk stratification; sudden cardiac death.