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ObjectivesOur objective in this study was to evaluate Tpeak-Tend interval (Tp-e) and other electrocardiographic parameters as risk factors for recurrence of life-threatening cardiac events in patients with the Brugada syndrome (BS).BackgroundThe Tp-e interval in the electrocardiogram (ECG) has been reported to predict life-threatening arrhythmias in the long QT syndrome.MethodsTwenty-nine patients with the ECG pattern of BS and 29 healthy age- and gender-matched controls were studied. The follow-up period was 42.65 ± 24.42 months (range 11 to 108 months).ResultsUpon presentation, five patients had suffered aborted sudden death, five syncope, and two presyncope. Eleven patients with the ECG pattern of BS had a prolonged (>460 ms) QTc in V2but usually not in inferior or left leads. No patient had abnormally prolonged QT dispersion. Programmed electrical stimulation induced ventricular tachycardia/fibrillation in 5 out of 26 patients. Inducibility did not predict recurrence of events. Cardioverter-defibrillators were implanted in 14 patients (all symptomatic and two asymptomatic). During follow-up, nine symptomatic patients experienced recurrences. Previous cardiac events and a QTc >460 ms in V2were significant risk factors (p = 0.00002 and p = 0.03, respectively). Tp-e and Tp-e dispersion were significantly prolonged in patients with recurrences versus patients without events (104.4 and 35.6 ms vs. 87.4 and 23.2 ms; p = 0.006 and p = 0.03, respectively) or controls (90.7 and 17.9 ms; p = 0.02 and p = 0.001, respectively).ConclusionsOur study demonstrates significant correlation between previous events, QTc >460 ms in V2, Tp-e, and Tp-e dispersion and occurrence of life-threatening arrhythmic events, suggesting that these parameters may be useful in risk stratification of patients with the Brugada syndrome.

In patients (Pts) with right ventricular dysplasia (RVD), radiofrequency catheter ablation (RFCA) has been reported to have low success rates and a high incidence of recurrences. Our study includes 11 (6 M/5 F, 42 ± 15 years) consecutive Pts with RVD and syncopal VT referred for evaluation. At the electrophysiologic study (EPS) VT was induced in every case, being syncopal in 1 Pt, nonsustained in 3, and sustained and well tolerated in 7. One of these 7 Pts had 9 different VT, only 3 of them mappable. Thus, only 6/11 Pts (55%) were eligible for RFCA. RF application was based on the identification of a fast bipolar deflection preceding the VT QRS and the confirmation in unipolar recordings that such a potential originated in the distal electrode. In 4/6 Pts (66%) we did ablate 7 distinct VT successfully (success is noninducibility of VT by programmed stimulation using up to 4 extrastimuli and 2–4 cycles lengths, at 1–2 RV sites). This potential, identified in all 7 VT induced in the 4 Pts with a successful outcome, preceded the VT GRS by 112 ± 74 ms (range 36–260). In 1/4Pts a nonsustained morphologically similar and faster VT was induced after interrupting the slower sustained VT with the first RF application. Under the guidance of pace-mapping this nonsustained VT was ablated and no longer inducible, but a defibrillator was implanted because of induction of short runs of very fast VT and a history of syncope on amiodarone. In the remaining 3Pts we did not induce any form of VT after RFCA. One Pt had an early recurrence and was successfully ablated at a second session. After 22 ± 6 months of follow-up the 4 Pts with successful RFCA continue asymptomatic and a repeat EPS performed in 3 Pts g 6 months after RFCA has been negative in all. Two of these 4 Pts are on 450 mg/day of propafenone (previously uneffective on higher doses) because of a family history of RVD and sudden death. Another Pt whose VT was ablated in the parahisian area developed A-V block and received a pacemaker. In conclusion RFCA can be attempted in 55% of Pts with RVD despite a previous history of syncopal VT with a success rate of 66%. RFCA can abolish distinct VT originating at different RV sites. The origin of VT in some Pts with RVD may be close to the His bundle and RF application result in AV block. In those Pts that really become noninducible after RFCA the recurrence rate is low. There are not mid-term recurrences.