Initiation of atrial fibrillation by ectopic beats originating from the superior vena cava: electrophysiological...

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Anatomy

Background:

• The superior vena cava (SVC) possesses cardiac musculature extending from the right atrium.
• Previous human studies have not detailed ectopic foci initiating paroxysmal atrial fibrillation (PAF) that may originate from the SVC.

Purpose of the Study:

• To investigate the origin of ectopic beats initiating paroxysmal atrial fibrillation (PAF).
• To evaluate the efficacy and safety of radiofrequency ablation for PAF originating from the SVC.

Main Methods:

• Included 130 patients with frequent PAF attacks.
• Utilized multiplane angiographic and intracardiac echocardiographic visualization to confirm SVC ectopic foci.
• Assessed radiofrequency energy applications and patient outcomes during follow-up.

Main Results:

• Eight patients (6%) exhibited PAF initiated by ectopic beats from the SVC.
• SVC ectopy showed a higher incidence of intra-atrial conduction block compared to pulmonary vein ectopy (75% vs. 37%).
• Radiofrequency ablation eliminated AF in all 8 patients, with no recurrence or SVC obstruction symptoms at 9-month follow-up.

Conclusions:

• Ectopic beats initiating PAF can originate from the SVC.
• Radiofrequency ablation is a highly effective and safe method for eliminating SVC-related ectopies and preventing PAF.