Abstract

Background and Introduction:
Torsades de Pointes (TdP) is a potentially fatal polymorphic ventricular tachycardia linked to QTc prolongation. It can arise from electrolyte imbalances, congenital long QT syndrome, or medications like fluoxetine, an SSRI known to inhibit the hERG potassium channel. Although rare, fluoxetine has been associated with TdP, though clear dosage-risk data is lacking. This case highlights fluoxetine as a potential contributor to TdP leading to cardiac arrest in a 35-year-old female who initially presented with nausea and vomiting.

Case Presentation:
A 35-year-old female with depression on daily fluoxetine, a history of binge drinking, and daily marijuana use presented to the ED with nausea and vomiting. Initial ECG revealed a QTc of 535 ms; serum magnesium was 1.4 mg/dL. While under observation, the patient developed TdP, followed by unresponsiveness and monomorphic V-Tach. Synchronized cardioversion (360J), IV magnesium sulfate (4g), and amiodarone (150 mg bolus + drip) were administered. The patient returned to sinus rhythm and remained stable. She was transferred to the ICU and advised to follow up regarding SSRI use and lifestyle changes.

Discussion:
This case is notable as fluoxetine was the only medication involved, and it is rarely implicated in TdP. Female sex and low magnesium were potential contributing factors. The patient's young age and lack of alcohol at the time complicate the usual TdP profile. The absence of typical prodromal symptoms and rapid progression to pulseless monomorphic V-Tach required immediate intervention. Real-time clinician recognition, not EKG notification, prompted timely cardioversion.

Conclusion:
This case emphasizes the need for clinical vigilance for TdP in patients with prolonged QTc, even in the absence of typical symptoms. SSRIs like fluoxetine, though rarely implicated, may contribute to TdP when combined with other risk factors. Prompt recognition and treatment are critical to avoid fatal outcomes.