Treatment of Ventricular Tachycardia Storm with Transvenous Overdrive Pacing in a Patient with a Normal QT Interval

Background: Ventricular tachycardia (VT) storm is usually treated with anti-arrhythmics; however, it is unclear how to treat refractory cases. Case Summary: A 65-year-old man with CAD s/p CABG and ICM presented after multiple VF shocks from a wearable cardiac defibrillator, 3 weeks post-NSTEMI that was non-revascularizable. He received a subcutaneous implantable cardioverter defibrillator (S-ICD). Subsequently, he went into medication-refractory polymorphic VT storm. Given the appearance of R-on-T phenomenon during episodes of sinus bradycardia despite a normal QTc interval, a TVP was emergently placed, and the VT was eliminated with overdrive pacing. Reduction of the backup pacing rate reinitiated VT. The S-ICD was exchanged for a transvenous ICD, with no further VT or ICD shocks. Conclusion: This case highlights the diagnostic and therapeutic value of overdrive pacing in medication‑refractory VT storm, even without QT prolongation, by demonstrating how pacing can suppress PVC‑triggered arrhythmias by modifying myocardial excitability. Overdrive pacing should be considered early in refractory VT storm—particularly when PVC‑triggered arrhythmias occur in the setting of bradycardia.