Steerable Delivery Sheath for Left Atrial Appendage Closure in Patients With Severely Enlarged Left Atria.

Background: Enlarged left atrium (LA) is frequently identified in patients who undergo left atrial appendage closure (LAAC) and negatively affects the device's final position and intervention results. Steerable delivery sheath (SDS) could represent an option to overcome these difficulties. We aimed to assess the feasibility of SDS-assisted procedures and compare their efficacy to the standard sheath strategy. Methods: This study analyzed patients from our institution's LAAC registry who had severe LA enlargement on CT scan (index LA volume >90 mL/m2) and underwent AMULET device implantation between January 2019 and March 2023. The patients underwent postprocedural CT scan to assess the device's position, residual LAA filling, and peridevice leaks. Results: A total of 195 consecutive patients were screened and 47 (24%) met the inclusion criteria (n = 22 SDS group; n = 25 standard group). There was no difference in baseline clinical, anatomical, or procedural characteristics. The procedural technical success (96%) and complication rates (9% vs 4%; P = .59) were comparable in both groups. Post-LAAC CT scans were obtained in 19 SDS group and 22 standard group patients. We observed significantly lower incidences of residual patent LAA (26% vs 72%; P = .005), peridevice leaks (16% vs 64%; P = .004), and off-axis device position (0% vs 27%; P = .02) in SDS compared to the standard group, suggesting a better LAA sealing. Conclusions: Severe LA enlargement was frequent among LAAC candidates. In this situation, the use of SDS appears feasible and safe, leading to more efficient closures on follow-up imaging without a higher risk of periprocedural complications.

Single-catheter simplified stepwise approach to persistent atrial fibrillation ablation: A feasibility study.

BACKGROUND: The strategy for atrial fibrillation ablation in persistent atrial fibrillation remains controversial. A single-catheter approach was recently validated for pulmonary vein isolation. AIM: To evaluate the feasibility of this approach to performing persistent atrial fibrillation ablation, including pulmonary vein isolation and atrial lines, if needed. METHODS: We prospectively included 159 consecutive patients referred to our centre for a first persistent atrial fibrillation ablation between January 2018 and December 2018. All patients underwent pulmonary vein isolation. If the patient was still in atrial fibrillation (spontaneously or inducible), we subsequently performed a stepwise approach, including roof line, anterior mitral line, posterior box lesion and cavotricuspid isthmus line. Finally, if patient remained in atrial fibrillation at the end of the procedure, a synchronized direct-current cardioversion was applied to restore sinus rhythm. RESULTS: At baseline, 54 patients were in sinus rhythm and underwent pulmonary vein isolation. For patients in atrial fibrillation, after pulmonary vein isolation and ablation of additional lines, if needed, 18 patients were converted to atrial tachycardia and one directly to sinus rhythm; 96 were still in atrial fibrillation and underwent direct-current cardioversion. After a mean follow-up of 17±6 months, 57 patients (36%) experienced atrial arrhythmia recurrence. No deaths, tamponades or phrenic nerve injuries were observed following the procedure. The main mode of arrhythmia recurrence was atrial fibrillation in 75% of cases and atrial tachycardia in 25% of cases. CONCLUSION: A single-catheter approach, including pulmonary vein isolation and atrial lines, is feasible and safe in patients undergoing persistent atrial fibrillation ablation, with an acceptable success rate of 64% at mid-term follow-up.

Definition of success criteria for ablation of typical right atrial flutter with a single-catheter approach: A pilot study.

BACKGROUND: The success rate of cavotricuspid isthmus ablation to treat right common flutter is high (up to 95%), but needs bidirectional block confirmation, requiring two or three catheters. AIM: To describe a new pacing technique using a single catheter to ablate and confirm cavotricuspid isthmus block with differential PR interval measurements. METHODS: We included 61 patients from five centres, who were referred for cavotricuspid isthmus ablation. All patients had cavotricuspid isthmus ablation, and the cavotricuspid isthmus block was confirmed by differential pacing using two or three catheters. The new method consisted of measuring the PR interval on the surface electrocardiogram using pacing from the tip of the ablation catheter on the lateral side (lateral delay) and the septal side (coronary sinus ostium) of the cavotricuspid isthmus line (difference=delta PR interval), before and after cavotricuspid isthmus ablation. We analysed the value of the delta PR interval in predicting bidirectional cavotricuspid isthmus block as confirmed by standard methods. RESULTS: Among our patient population (mean age 63±12 years), 39 patients were ablated during sinus rhythm, and 22 during common flutter. Cavotricuspid isthmus block was achieved in all patients but one. Lateral delay and delta PR interval increased significantly after validation of cavotricuspid isthmus block (257±42 vs. 318±50ms and 32±23 vs. 96±22ms, respectively; P<0.0001). A delta PR interval cut-off of ≥70ms had 100% sensitivity and specificity to predict bidirectional cavotricuspid isthmus block. CONCLUSIONS: A single-catheter ablation approach to performing cavotricuspid isthmus line based on surface electrocardiogram PR interval measurement is feasible. After ablation, cavotricuspid isthmus block was systematically obtained when the delta PR interval was>70ms.