Epicardial Radiofrequency Catheter Ablation in Patients With Brugada Syndrome

The activation recovery interval, which serves as a surrogate marker for the duration of the action potential, will be measured on both the epicardial and endocardial surfaces of the right ventricular outflow tract. This measurement will be taken from the onset of the minimum of the derivative of ventricular activation (dVdT) to the end of ventricular repolarization, following the classic methodology

Abnormal electrical potentials were defined as low-frequency electrograms (up to 100 Hz) with prolonged duration (>200 ms), fragmented patterns (more than three deflections), and late components extending beyond the QRS complex

Measured by unipolar catheters placed in the epicardial and endocardial ventricular surfaces

Maximum length of ventricular signs on bipolar electrogram

Programmed electrical stimulation will be performed at two locations: the right ventricular apex and the right ventricular outflow tract, unless the patient experiences inducible ventricular tachycardia at the first site. The stimulation will use energy that is twice the diastolic threshold. Two drive cycles will be implemented: S1 at 600 ms and S1 at 430 ms. Up to two additional stimuli (S2 and S3) will be applied, with a minimum coupling time of 200 ms. A positive result from the programmed ventricular stimulation is identified if sustained ventricular fibrillation or polymorphic ventricular tachycardia is induced.

Acute post-procedure complications were monitored over a three-day hospital stay, focusing on major events such as sustained ventricular arrhythmias, cardiac arrest, death, thromboembolic events, subxiphoid puncture accidents (significant bleeding (≥ 500 ml), or pericardial tamponade necessitating surgical intervention), and pericarditis. Diagnosis of pericarditis was based on characteristic pain, pericardial effusion, electrocardiographic findings (PR segment depression and diffuse ST-segment elevation), and elevated serum inflammatory markers.

Upward ST segment elevation ST-segment elevation ≥2 mm followed by a negative T wave (type 1 Brugada electrocardiographic pattern) in one or more right precordial leads V1 and/or V2 positioned in the second, third, or fourth intercostal spaces.

Upward ST segment elevation ST-segment elevation ≥2 mm followed by a negative T wave (type 1 Brugada electrocardiographic pattern) in one or more right precordial leads V1 and/or V2 positioned in the second, third, or fourth intercostal spaces, during treadmill test.

Upward ST segment elevation ST-segment elevation ≥2 mm followed by a negative T wave (type 1 Brugada electrocardiographic pattern) in one or more right precordial leads V1 and/or V2 positioned in the second, third, or fourth intercostal spaces during 12 lead 24h Holter ECG Monitoring

Upward ST-segment elevation ≥2 mm followed by a negative T wave (type 1 Brugada electrocardiographic pattern) in one or more right precordial leads V1 and/or V2 positioned in the second, third, or fourth intercostal spaces after an ajmaline challenge after an ajmaline challenge

Occurrence of at least one of the following: arrhythmic syncope, documented sustained ventricular tachycardia or ventricular fibrillation, sudden cardiac death or appropriate implantable cardiac defibrillator therapy

Induced sustained ventricular arrhythmias during programmed ventricular stimulation one year after the intervention or any life-threatening events (such as arrhythmic syncope, spontaneous sustained ventricular arrhythmias, appropriate ICD therapy, or sudden arrhythmic death) throughout at least 12 months of follow-up.