REBEL Core Cast 145.0: Understanding QTc Prolongation: Causes, Risks, and Management

The QT interval represents the duration of ventricular depolarization and repolarization, with prolongation significantly increasing the risk of Torsades de Pointes, a potentially fatal polymorphic ventricular tachycardia. While computer-generated QTc readings are standard in high-volume emergency departments, manual calculation remains necessary for high-risk patients presenting with syncope or complex medication profiles. Common triggers include electrolyte disturbances like hypokalemia and hypomagnesemia, alongside medications such as ondansetron, antipsychotics, and fluoroquinolones. Management of Torsades de Pointes requires immediate defibrillation for non-perfusing rhythms, followed by magnesium administration. For asymptomatic patients with prolonged QTc, clinical focus shifts to identifying underlying causes, correcting electrolyte abnormalities, and performing thorough medication reconciliation. Cardiology consultation is recommended for patients exceeding a 600-millisecond threshold to ensure appropriate follow-up and risk mitigation.