Table 9.
Clinical variables associated with an increased risk of major arrhythmic events in Brugada syndrome.⁎
| Variable | No. patients | Prevention | Study endpoint | Multivariable analysis [hazard ratio (95% confidence interval), P value] | Reference |
|---|---|---|---|---|---|
| History | |||||
| Previous VF | 93 | P/S | SD, cardiac arrest, or sustained VT/VF (N = 25) | N/A (N/A),.005 | Makimoto [292] |
| Cardiac arrest | 1029 | P/S | SD (N = 7), appropriate ICD | 11 (4.8–24.3),.001 | Probst [359] |
| shocks (N = 44), or sustained VT/VF (N = 0) | |||||
| Syncope or cardiac arrest | 460 | P/S | VF or SD (N = 38) | 12.7 (4.5–53.4), o.0001 | Takagi [360] |
| Syncope of unknown origin | 547 | P | SD (N = 16), VF (N = 29) | 2.5 (1.2–5.3),.017 | Brugada [361] |
| Syncope | 44 | P/S | SCD (N = 5), polymorphic VT or VF (recorded by ECG, Holter, or ICD) (N = 7), or syncope of unknown etiology (11) | 3.6 (1.09–11.7),.035 | Huang [362] |
| Syncope þ spontaneous type 1 ECG | 200 | P/S | VF or SD from birth (N = 22) | 6.4 (1.9–21), o.002 | Priori [363] |
| Syncope of probable arrhythmic origin | 1029 | P/S | SD (N = 7), appropriate ICD | 3.4 (1.6–7.4),.002 | Kamakura [364] |
| shocks (N = 44), or sustained VT/VF (N = 0) | |||||
| Syncope | 320 | P | SD (N = 3), appropriate ICD shocks (N = 14), or sustained VT/VF (N = 0) | 2.8 (1.1–8.1),.03 | Delise [262] |
| Syncope þ spontaneous type 1 ECG | 308 | P | VF (N = 1) or appropriate ICD intervention (N = 13) | 4.2 (1.4–12.8),.012 | Priori [49] |
| Ventricular refractoriness | |||||
| Ventricular refractory period o200 ms | 308 | P | VF (N = 1) or appropriate ICD intervention (N = 13) | 3.9 (1.03–12.8),.045 | Priori [49] |
| ECG characteristics | |||||
| Spontaneous type 1 ECG | 1029 | P/S | SD (N = 7), appropriate ICD | 1.8 (1.03–3.3),.04 | Probst [247] |
| shocks (N = 44), or sustained VT/VF (N = 0) | |||||
| Spontaneous type 1 ECG | 320 | P | SD (N = 3), appropriate ICD shocks (N = 14) or sustained VT/VF (N = 0) | 6.2 (1.8–40),.002 | Delise [262] |
| QRS fragmentation (≥2 spikes within the QRS complex in leads V1–V3) | 308 | P | VF (N = 1) or appropriate ICD intervention (N = 13) | 4.9 (1.5–1.8),.007 | Priori [49] |
| Family history of sudden cardiac death at age 45 years | 330 | P | VF (N = 56), syncope (N = 67), or asymptomatic (N = 207) | 3.28 (1.4–7.6),.005 | Kamakura [364] |
| J wave in inferior and lateral leads | 330 | P | VF (N = 56), syncope (N = 67), or asymptomatic (N = 207) | 2.66 (1.1–6.7),.005 | Kamakura [364] |
| QRS duration 490 ms in lead V2 | 460 | P/S | VF or SD (N = 38) | 3.6 (1.4–12.2),.007 | Takagi [360] |
| Horizontal ST segment after J wave (ST-segment elevation ≤0.1 mV within 100 ms after J point and continued as a flat ST segment until onset of T wave in ≥1 lead with J wave) | 460 | P/S | VF or SD (N = 38) | 410 (1.9–20.2),.02 | Takagi [360] |
| Late potentials (root mean square voltage of terminal 40 ms of filtered QRS complex o20 μV þ duration of low-amplitude signals o40 μV of QRS in terminal filtered QRS complex 438 ms) | 44 | P/S | SCD (N = 5), polymorphic VT or VF (recorded by ECG, Holter, or ICD) (N = 7), or syncope of unknown etiology (11) | 10.9 (1.1–104),.038 | Huang [362] |
| ST-segment augmentation at early recovery of exercise test (ST-segment amplitude increase ≥0.05 mV in at least 1 of V1–V3leads at 1–4 minutes of recovery compared with ST-segment amplitude at pre-exercise) | 93 | P/S | SD, cardiac arrest, or sustained VT/VF (N = 25). | N/A (N/A),.007 | Makimoto [292] |
ICD = implantable cardioverter-defibrillator; N/A = not available; P = primary prevention patients only; P/S = primary and secondary prevention patients; SD = sudden death, VF = ventricular fibrillation, VT = ventricular tachycardia
⁎
The list includes predictor variables that have been associated with an increased risk of major arrhythmic events (i.e., SCD, appropriate ICD interventions, or ICD therapy on fast VT/VF) in at least 1 published multivariable analysis in prospective studies.