Tpeak-Tend and Tpeak-Tend Dispersion as Risk Factors for Ventricular Tachycardia/ Ventricular Fibrillation in Patients With the Brugada Syndrome

OBJECTIVES Our 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). BACKGROUND The Tp-e interval in the electrocardiogram (ECG) has been reported to predict life-threatening arrhythmias in the long QT syndrome. METHODS: Twenty-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). RESULTS Upon 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 V2 but 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 V2 were 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).CONCLUSIONS Our 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(AU)

OBJETIVOS Nuestro objetivo en este estudio fue evaluar Tpeak-Tienden intervalo (Tp-e) y otros parámetros electrocardiográficos como factores de riesgo para la recurrencia en peligro la vida de eventos cardíacos en pacientes con el síndrome de Brugada (BS). ANTECEDENTES El Tp-e intervalo en el electrocardiograma (ECG) se ha informado a predecir las arritmias que amenazan la vida en el síndrome del QT largo. MÉTODOS: Veintinueve pacientes con el patrón de ECG de BS y 29 sanos de edad y el sexo-los controles se estudiaron. El período de seguimiento fue de 42,65 ± 24,42 meses (rango 11 a 108 meses). RESULTADOS: Tras la presentación, cinco pacientes habían sufrido una muerte súbita abortada, cinco síncope, y dos presincope. Once pacientes con el patrón de ECG BS había un prolongado (> 460 ms) QTc en V2 pero generalmente no en la izquierda inferior o conduce. Ningún paciente había anormalmente dispersión QT prolongado. Inducida por la estimulación eléctrica programada taquicardia ventricular / fibrilación en 5 de 26 pacientes. Inducibility no predecir la recurrencia de eventos. Cardioverter-desfibriladores se implantaron en 14 pacientes (todos los sintomáticos y dos asintomáticos). Durante el seguimiento, nueve pacientes presentaron recidivas sintomáticas. Anteriores eventos cardíacos y un QTc> 460 ms en V2 fueron importantes factores de riesgo (p = 0,00002 yp = 0,03, respectivamente). Tp y Tp-e-e dispersión se prolongó significativamente en los pacientes con recidivas frente a los pacientes sin eventos (104,4 y 35,6 ms frente a 87,4 y el 23,2 ms, p = 0,006 y p = 0,03, respectivamente) o los controles (90,7 y 17,9 m, p = 0,02 yp = 0,001, respectivamente)..........

Unusual response to the ajmaline test in a patient with Brugada syndrome.

We present a Brugada syndrome patient who suffered an aborted sudden death. The ajmaline test (1 mg/kg body weight) induced accentuated alternans ST-segment elevation in V1-V2 without ventricular arrhythmias. It could represent silent ischaemia not detected before, failure of myocardial regions to repolarize in alternate beats due to transmural dispersion of conduction and refractoriness in the right ventricular outflow tract or a rate dependent sodium channel block by ajmaline. We need more studies to know whether this electrocardiographic sign is a risk factor for life-threatening ventricular arrhythmias in Brugada syndrome patients.