Fellow Physician Allegheny General Hospital Mechanicsburg, Pennsylvania, United States
Background: Levetiracetam has been shown to potentiate QT prolongation in individuals with long QT syndrome. These commonly use anti-epileptic agent should be used with caution alongside other QT-prolonging agents, such as class III anti-arrhythmics, due to the elevated risk of long-short sequence-induced polymorphic ventricular tachycardia.
Methods: A 61-year-old male with a history of cocaine and alcohol use disorder, unmanaged seizure disorder, heart failure with reduced ejection fraction (HFrEF), prolonged QT syndrome status post secondary prevention ICD who was initially admitted to the hospital with nonspecific abdominal pain. He was initially treated for colitis, but he showed minimal improvement and had progressively worsening abdominal pain associated with tachycardia and shortness of breath. Brief antiarrhythmic therapy was initiated on telemetry floors, which was also ineffective for persistent tachycardia. The cardiology team was consulted for tachycardia, who determined his symptoms were likely due to heart failure-related shock rather than gastrointestinal disease. He was transferred to the cardiac ICU, where anti-arrhythmic therapy was discontinued, diuresis was initiated, and QTc intervals were closely monitored. Neurology was consulted to manage his seizures, underscoring the need for coordinated care in complex cases.
Outcome: The patient initially showed hemodynamic improvement following diuresis however, he soon developed increasing lethargy. Due to concerns for ongoing seizures, the patient received a bolus of levetiracetam followed by maintenance dosing. Shortly thereafter, he developed a surge long-short sequences despite stable electrolytes and previously normal QTc. With concerns for imminent Torsade's de Pointes (TdP), lidocaine was initiated however prior to medication administration, his ICD delivered three consecutive shocks for TdP associated with hypotension, though the patient maintained pulses. Emergency interventions included magnesium administration, ICD deactivation with an external magnet for patient comfort, and external cardioversion. He was subsequently intubated for airway protection and ongoing VT stabilization, highlighting the delicate balance required in managing neurological and cardiac complications in complex cases.
Conclusion: Concurrent use of anti-epileptics and anti-arrhythmics heightens the risk of torsades de pointes and long-short sequences. Vigilant monitoring is critical to prevent life-threatening arrhythmias, especially in high-risk patients in the cardiac intensive care unit.
