Table 1.
Definition, Incidence and Prognostic Implications of Electrical Storm
| Author | ES Definition | ES Incidence (patients) | ES Prognosis | Remarks |
|---|---|---|---|---|
| Kowey 10 | ≥2 hemo‐dynamically relevant VT in 24 hour | (All patients) | ↓ (Mortality 13.6% in 48 hour) | AAD study with ES as inclusion criterion |
| Villacastin 5 | ≥2 shocks for one VT episode | 16/80 (20%) | ↓ | DFT? |
| Fries 9 | ≥2 VT separated by ≤ 1 hour SR | 34/57 (60%) | ↓ | Post implant VT included |
| Credner 18 | ≥3 VT in 24 hour | 14/136 (10%) | Ø | Only treated VT |
| Nademanee 17 | ≥20 VT in 24 hour or ≥4 VT in 1 hour | (All patients) | ↓ (1‐year mortality 95% on AAD and 33% on β blocker) | Study on AAD versus β blocker in ES |
| Exner 12 | ≥3 VT in 24 hour | 90/457 (20%) | ↓ (RR 2.4) | Only treated VT |
| Greene 19 | ≥3 VT in 24 hour | 40/227 (18%) | Ø | Only treated VT |
| Bänsch 15 | ≥3 VT in 24 hour | 30/106 (28%) | ↓ | Only DCM |
| Verma 23 | ≥2 VT requiring shock in 24 hour | 208/2028 (10%) | ↓ | |
| Wood 7 | ≥3 VT in 24 hour | 50/521 (9.5%) | (Not analyzed) | |
| Stuber 16 | ≥3 VT in 2 weeks | 51/214 (24%) | ↓: 5 year mortality 33 versus 13% | Only treated VT |
| Hohnloser 20 | ≥3 separate VT in 24 hour | 148/633 (23%) | Ø | Treatment with azimilide; all patients had had VT before |
| Arya 38 | ≥3 VT in 24 hour | 22/162 (14%) | NA | |
| Brigadeau 39 | ≥2 separate VT in 24 hour | 123/307 (40%) | Ø | |
| Gatzoulis 40 | ≥3 VT in 24 hour | 32/169 (19%) | ↓: Mortality 53 versus 14% during 33 ± 26 months |
The studies by Kowey et al. 10 and Nademanee et al. 17 included patients without an ICD. AAD = antiarrhythmic drugs, DCM = dilative cardiomyopathy; DFT = defibrillation threshold; ES = electrical storm; RR = relative risk; SR = sinus rhythm; vs = versus; VT = ventricular tachyarrhythmia; Ø= no influence on prognosis; ↓= reduced prognosis.