Procedure: Pulmonary vein isolation (PVI) using a pentaspline pulsed field ablation (PFA) catheter (FARAWAVE) was performed according to a published standard protocol using 8 applications per pulmonary vein. After PVI and electrical cardioversion there was repeated reinduction of atrial fibrillation with the earliest activation observed in the right atrium. The FARAWAVE-catheter was then used to further map the trigger of these episodes and the superior vena cava (SVC) was found to be the location of the earliest activation. Using the basket-configuration of the catheter, PFA was performed at the SVC entrance (Figure 1), successfully isolating the SVC, and thus eliminating the trigger with only one application (Figure 2). No phrenic nerve palsy occurred. Immediately after the application, a junctional rhythm (40 bpm) was observed. It lasted for 30 minutes until sinus rhythm (50-60 bpm) reoccurred. The patient was discharged after two days in sinus rhythm without antiarrhythmic drugs.
Follow-up: 3-month follow-up showed no recurrence of atrial tachyarrhythmia without antiarrhythmic drugs. Further follow-up data will be assessed and reported.
Conclusion: The tissue selectivity of PFA allows a safe ablation of myocardium in proximity of susceptible extracardiac structures. We present a case of a successful SVC isolation without damage to the phrenic nerve. However, because of the extent of the lesions, attention must be paid to surrounding myocardial tissue. In our case, the temporary junctional rhythm after energy application could either be explained by potential sinus node damage or a prolonged autonomic response.
Figure 1
Figure 2
https://dgk.org/kongress_programme/ht2023/aV655.html