Electrical storm (ES) is a devastating and life-threatening event in clinical practice, but its real weight as a risk factor and its clinical predictors remain unclear. Our objective was to evaluate ES as a mortality and morbidity risk factor and to define the clinical variables associated with ES. The meta-analysis was performed according to the PRISMA guidelines. At the end of the selection process, 13 studies were collected and included in the quantitative analysis. Mortality and morbidity due to ES were assessed. The most acknowledged ES predictors were taken into account in separate sub-analyses. The whole cohort included 5912 patients (857 with ES). Risk of death was increased in the ES group [risk ratio (RR) 3.15; 95% confidence interval (CI) 2.22–4.48]. Electrical storm was also associated with increased composite risk of all-cause death, cardiac transplantation, and hospitalization for acute heart failure (RR 3.39; 95% CI 2.31–4.97). These results were confirmed by comparing the ES group with patients with or without previous unclustered episodes of ventricular arrhythmias. Moreover, implantable cardioverter-defibrillator (ICD) for secondary prevention, lower ejection fraction, monomorphic ventricular tachycardia as triggering arrhythmia, and class I anti-arrhythmic drugs therapy were all associated with ES. Electrical storm is a strong mortality risk factor and it is associated with an increased combined risk of death, heart transplantation, and hospitalization for heart failure. Implantable cardioverter-defibrillator for secondary prevention, monomorphic ventricular tachycardia as triggering arrhythmia, lower ejection fraction, and class I anti-arrhythmic drugs therapy are all associated with ES and could be used to define specific populations with higher risk to develop ES.

Background: Current literature only reports variable information from single‐center studies on the recurrence rate, the complications, and the outcome of patients with Takotsubo syndrome ( TTS) experiencing recurrent TTS . Therefore, a detailed description of clinical characteristics, predictors, and the prognostic impact of patients with TTS and recurrences in a multicenter registry is needed. Methods and Results: We analyzed 749 patients with TTS from 9 European centers being part of the international, multicenter GEIST (German Italian Stress Cardiomyopathy) Registry. Patients were divided into the recurrence group and the nonrecurrence group. The recurrence rate at a median follow‐up of 830 days (interquartile range, 118–1701 days) was 4%. Most recurrences were documented in the first 5 years after the index TTS episode. Up to 2 TTS recurrences were documented in 2 of 30 patients (6%). A variable ballooning pattern (n=6, 0.8%) with, in particular, involvement of the right ventricular occurred in 3 cases (0.4%) at the recurrence event. Except for the higher presence of arterial hypertension (86.7% versus 68.3%; P =0.03) in the recurrence group, no other baseline characteristics were different between groups. Observation of TTS complications during follow‐up, including stroke, thromboembolic events, in‐hospital death, and cardiogenic shock, revealed no significant differences between groups ( P >0.05), except the higher presence of pulmonary edema in the recurrence group versus the nonrecurrence group (13.3% versus 4.9%; P =0.04). Conclusions: The incidence of TTS recurrence is estimated to be 4% in this multicenter TTS registry. A variable TTS pattern at recurrence is common in up to 20% of recurrence cases.

Takotsubo syndrome (TTS) is an acute heart failure syndrome featured by transient and reversible left ventricular (LV) dysfunction.¹ The mechanism leading to the transient LV systolic dysfunction characteristic of TTS is still unclear; however, increased serum levels of catecholamines may be one of the main causes.²