Predictors of Polymorphic Ventricular Tachycardia and Ventricular Fibrillation in Patients With Takotsubo Syndrome

Polymorphic ventricular tachycardia (PVT) and ventricular fibrillation (VF) are life-threatening complications of takotsubo syndrome (TTS). Data regarding risk factors for PVT/VF based on the TTS variant are lacking. This study aimed to identify demographic and clinical factors associated with PVT and VF in patients with TTS. Patients meeting the InterTak criteria for TTS between 2010 and 2022 were retrospectively identified. The occurrence of PVT/VF with each risk factor was analyzed using logistic regression. Sensitivity analysis was performed to assess the interaction between risk factors. PVT/VF occurred in 27 of 296 patients with TTS (9.1%). Patients with PVT/VF were younger (52 vs 62 years, p = 0.019) and more frequently used stimulants in the 4 weeks before admission (22.2% vs 8.2%, odds ratio [OR] 3.20, p = 0.023). All PVT/VF occurred within 24 hours of hospitalization. An initial QTc threshold of 490 ms had the highest sensitivity and specificity for the occurrence of PVT/VF (area under the curve = 0.687). Patients with PVT/VF were more likely to have a QTc >490 ms on admission (55.6% vs 18.7%, OR 5.45, p <0.01), apical variant TTS (78% vs 56%, OR 2.69, p = 0.038), and an admission ejection fraction <30% (63% vs 41.5%, OR 2.39, p = 0.032); each factor was independently associated with PVT/VF irrespective of QTc duration on sensitivity analysis. In conclusion, nearly 1 in 10 patients with TTS had PVT/VF. A QTc >490 ms, recent stimulant use, apical variant TTS, and severe left ventricular systolic dysfunction on admission are associated with higher PVT/VF risk, with the first 24 hours being a high-risk period.