Brugada-type ECG (brugada-type + ecg)

Distribution by Scientific Domains

Selected Abstracts

The Full Stomach Test as a Novel Diagnostic Technique for Identifying Patients at Risk of Brugada Syndrome

Introduction: Autonomic modulation, particularly high vagal tone, plays an important role in the occurrence of ventricular tachyarrhythmias in the Brugada syndrome. Food intake modulates vagal activity. We assessed the usefulness of a novel diagnostic technique, the "full stomach test," for identifying a high-risk group in patients with a Brugada-type electrocardiogram (ECG). Methods and Results: In 35 patients with a Brugada-type ECG, we assessed 12-lead ECGs before and after a large meal, a pilsicainide pharmacological test, spontaneous ST-segment change, late potentials by signal-averaged ECG, microvolt T-wave alternans, and four other ECG parameters. These patients were divided into two groups (i.e., high-risk group [n = 17] and indeterminate risk group [n = 18]). The full stomach test was defined as positive when augmentation of characteristic ECG abnormalities was observed after meals. Thirteen patients had a prior history of life-threatening events such as aborted sudden death and syncope, with a total of 30 episodes. These episodes had a circadian pattern, at night and after meals. The full stomach test was positive in 17 of the study patients (49%). A positive test outcome was characterized by a higher incidence of a history of life-threatening events than a negative test outcome (P = 0.015, odds ratio = 7.1). In comparison between the two groups, the incidence (82%) of positive outcomes in the high-risk group was significantly higher than that (17%) in the indeterminate risk group (P = 0.0002). Conclusions: Characteristic ECG changes diagnostic of Brugada syndrome are augmented by a large meal. These data are associated with a history of life-threatening events in Brugada syndrome. [source]

Site-Specific Arrhythmogenesis in Patients with Brugada Syndrome

Introduction: It has been believed that electrophysiologic abnormality of the epicardial region of the right ventricular free wall may play an important role in arrhythmogenesis of phase 2 reentry in Brugada syndrome, but clinical evidence of the occurrence of ventricular arrhythmias at the right ventricular free wall has not been evaluated. In this study, we evaluated the site-specific inducibility of ventricular fibrillation (VF) and the origin of spontaneous premature ventricular contractions (PVCs) in patients with Brugada syndrome. Methods and Results. Forty-five patients with Brugada-type ECG were enrolled in this study. Spontaneous PVCs were recorded in 9 patients. Programmed electrical stimulation (PES) was performed at the right ventricular apex (RVA), the free wall and septal region of the right ventricular outflow tract (RVOT), and the left ventricle (LV). The inducibility of PVT/VF was evaluated at each ventricular site, and the origin of PVC was determined by pace mapping. Sustained VF was induced in 17 patients. VF was induced in all 17 patients by PES at RVOT. Although PES at the septal region of the RVOT induced VF in only 5 patients (29%), PES at the free-wall region of the RVOT induced PVT/VF in 13 patients (76%). PES at RVA induced VF in only 2 patients (12%), and PES at LV failed to induce any arrhythmic events. Ventricular pace mapping showed that 64% of PVCs occurred at the free-wall region of the RVOT, 18% at the septal region of the RVOT, 9% at RVA, and 9% at LV. Conclusion: VF in patients with Brugada syndrome frequently is induced at the free-wall region of the RVOT area. The origin of PVC appears to be related to the site of PVT/VF induction by PES.(J Cardiovasc Electrophysiol, Vol. 14, pp. 373-379, April 2003) [source]

Relatively Benign Clinical Course in Asymptomatic Patients with Brugada-Type Electrocardiogram Without Family History of Sudden Death

Asymptomatic Brugada-Type ECG.Introduction: The incidence of sudden death or ventricular fibrillation (VF) in asymptomatic Brugada syndrome patients with a family history of sudden death is reported to be very high. However, there are few reports on the prognosis of asymptomatic Brugada syndrome patients without a family history of sudden death. Methods and Results: Eleven patients (all male; mean age 40.5 9.6 years, range 26 to 56) with asymptomatic Brugada-type ECG who had no family history of sudden death were evaluated. The degrees of ST segment elevation and conduction delay on signal-averaged ECG (SAECG) before and after pilsicainide were evaluated in all 11 patients. VF inducibility by ventricular electrical stimulation also was evaluated in 8 of 11 patients. Patients were followed for a period of 9 to 84 months (mean 42.5 21.6). The J point level was increased (V1 :0.19 0.09 mV to 0.36 0.23 mV; V2: 0.31 0.12 mV to 0.67 0.35 mV) by pilsicainide. Conduction delay was increased (total QRS: 112.2 6.3 msec to 131 7 6.3 msec; under 40 , V: 42.0 8.5 msec to 52.7 12.7 msec; last 40 msec: 17.4 5.9 , V to 10.4 6.1 , V) on SAECG by pilsicainide. VF was induced in only 1 of 8 patients. None of the patients had syncope or sudden death during a mean follow-up of 42.5 21.6 months. Conclusion: This study suggests that asymptomatic patients with Brugada-type ECG who have no family history of sudden death have a relatively benign clinical course. [source]

Intravenous Administration of Class I Antiarrhythmic Drug Induced T Wave Alternans in an Asymptomatic Brugada Syndrome Patient

A 53-year-old man with an abnormal ECG was referred to the Nihon University School of Medicine. The 12-lead ECG showed right bundle branch block and saddleback-type ST elevation in leads V1,V3 (Brugada-type ECG). Signal-averaged ECG showed positive late potentials. Double ventricular extrastimuli (S1: 500 ms, S2: 250 ms, S3: 210 ms) induced VF. Amiodarone (200 mg/day) was administered for 6 months and programmed ventricular stimulation was repeated. VF was induced again by double ventricular stimuli (S1: 600 ms, S2: 240 ms, S3: 170 ms). Intravenous administration of class Ic antiarrhythmic drug, pilsicainide (1 mg/kg), augmented ST-T elevation in leads V1,V3, and visible ST-T alternans that was enhanced by atrial pacing was observed in leads V2 and V3. Visible ST-T wave alternans disappeared in 15 minutes. However, microvolt T wave alternans was present during atrial pacing at a rate of 70/min without visible ST-T alternans. (PACE 2003; 26:1900,1903) [source]

Assessment of Markers for Identifying Patients at Risk for Life-Threatening Arrhythmic Events in Brugada Syndrome

Introduction: Risk stratification for life-threatening arrhythmic events in Brugada syndrome is not yet established. The aim of the present study was to examine the usefulness of various markers in predicting life-threatening arrhythmic events in the Brugada syndrome. Methods and Results: Forty-six patients with Brugada-type ECGs were categorized into the symptomatic (n = 28) and asymptomatic (n = 18) groups. Statistical analyses were performed with respect to the usefulness of the following markers: SCN5A mutation, pharmacologic challenge, ventricular fibrillation (VF) inducibility by programmed electrical stimulation, and late potential (LP) by signal-averaged ECG (SAECG). Comparison between the two groups revealed a significant difference only in LP positivity (92.6% vs 47.1%, P = 0.0004). The symptomatic group had significantly lower RMS40, longer LAS40, and longer fQRSd compared with the asymptomatic group. A significant difference was noted, especially RMS40. The positive predictive value, negative predictive value, and predictive accuracy when setting a cutoff value of 15 ,V were 92.0%, 78.9%, and 86.4%, respectively. Furthermore, patients with an RMS40 value <15 ,V (n = 25) showed significantly higher rates of VF recurrence compared with patients with an RMS40 value , 15 ,V (n = 19, P = 0.047). Conclusion: Regarding risk stratification for identifying high-risk patients in Brugada syndrome, only LP by SAECG was shown to be useful, suggesting the importance of RMS40 in predicting the history of life-threatening arrhythmic events and the recurrence of VF. [source]