A single extrastimulus from the right atrial appendage and superior vena cava prolonged conduction time via the venoatrial junction by 81 ± 49.7 ms and 61 ± 58.7 ms, respectively.
Observational (n=25)
What are the electrophysiological properties of the superior vena cava and venoatrial junction in patients with atrial fibrillation?
Pacing maneuvers demonstrate intracaval conduction delay and decremental conduction via the venoatrial junction, which can facilitate mapping of optimal ablation sites for superior vena cava isolation.
BACKGROUND: Although the superior vena cava (SVC) has been well known to be one of the important foci triggering atrial fibrillation (AF), its electrophysiological characteristics have received little research attention. The aim of this study was to investigate the electrophysiological properties of the SVC and venoatrial junction (VAJ). METHODS: Twenty-five consecutive AF patients without structural heart disease undergoing electrical SVC isolation were included in this study. After pulmonary vein isolation, a circular decapolar catheter and 2 multipolar catheters were emplaced in the VAJ, right atrial appendage (RAA), and SVC, respectively. Burst pacing and single extrastimulus were applied from the RAA and SVC. The atrial and caval potentials on the circular catheter in the VAJ were investigated. RESULTS: Intracaval conduction delay and various degrees of conduction block over the VAJ were observed with burst pacing from both the RAA and SVC. A single extrastimulus from the RAA and SVC with a basic cycle length of 600 milliseconds prolonged the conduction time via the VAJ by 81 ± 49.7 milliseconds and 61 ± 58.7 milliseconds, respectively. The atrial and caval electrograms at the VAJ, which were separated from each other by pacing applications, facilitated mapping of the earliest activation site at the VAJ. CONCLUSIONS: Intracaval conduction delay and decremental conduction property via the VAJ were demonstrated using pacing maneuvers. Pacing applications from the RAA or SVC can help distinguish the atrial and caval potentials and can facilitate mapping of the optimal ablation sites to isolate the SVC.
Fukumoto et al. (Mon,) conducted a observational in Atrial Fibrillation (n=25). Burst pacing and single extrastimulus from the right atrial appendage and superior vena cava was evaluated on Prolongation of conduction time via the venoatrial junction. A single extrastimulus from the right atrial appendage and superior vena cava prolonged conduction time via the venoatrial junction by 81 ± 49.7 ms and 61 ± 58.7 ms, respectively.