Optimization of superior vena cava isolation with aid of ablation index guidance

Initial experience of transoesophageal echocardiography-guided percutaneous pulsed field ablation of atrial fibrillation

OBJECTIVE

Pulsed-field ablation (PFA) is a new technology of catheter ablation for atrial fibrillation (AF). This research is to investigate the feasibility of a new strategy (transoesophageal echocardiography-guided pulsed field ablation, TEEP) to guide PFA for AF with no contrast and zero fluoroscopy.

METHODS

Patients with AF underwent TEEP under general anaesthesia with the guidance of three-dimensional (3D) transoesophageal echocardiography (TEE) throughout the procedure. After a successful transseptal puncture, the PFA catheter (CardiPulse) was delivered to the different pulmonary veins sequentially for standard PFA, and the pulmonary vein electrical isolation (PVI) was observed in real-time. After the ablation, left atrial bipolar voltage mapping under sinus rhythm was performed to verify the PVI.

RESULTS

10 patients with AF were enrolled, including 6 patients with paroxysmal AF and 4 patients with persistent AF. The mean operative time was 99±14 min, the mean time of the left atrial manoeuvre was 66±23 min, and the mean PFA ablation time was 105±8 s. First-pass PVI of all veins was achieved in all patients, thus no additional PFA applications were needed after the initial set. No contrast was needed and no X-ray was exposed. No complications were observed.

CONCLUSIONS

We report the preliminary application of 3D TEE-guided PFA for AF in the world. Its immediate safety and efficacy are promising. Compared with traditional PFA procedures, TEEP has many advantages, including accuracy of the transeptal puncture, direct visualisation of contact between the catheter and myocardial tissue, no contrast and zero fluoroscopy.

Voltage-Guided and Non-Voltage-Guided Superior Vena Cava Isolation in Patients With Atrial Fibrillation

BACKGROUND

In addition to the pulmonary vein, the superior vena cava (SVC) is an important focus of atrial fibrillation (AF). However, SVC isolation may cause serious complications, and appropriate settings and techniques for SVC isolation are lacking.

METHODS

This study enrolled 86 consecutive patients with AF who underwent SVC isolation. Voltage mapping using a multi-electrode catheter and ablation were performed under the guidance of an electro-anatomical mapping system. The lines encircling the SVC were divided into eight anatomic segments on the SVC geometry, and each segment was subjected to voltage-guided (VG) ablation in decreasing order of voltage (starting from the segment with the highest voltage). Non-VG (NVG) ablation was performed anatomically from the anterior wall toward the septum with one-round cautery.

RESULTS

A total of 86 cases (66 males, mean age 69 [60, 74], mean CHA2DS2 VASc score 2 [1, 3], 58 paroxysmal AF) with AF were included for ablation. Electrical SVC isolation was successfully achieved in all patients. The length of the myocardial sleeves, as measured from the SVC-RA junction to the end of the local signal, was 37 [28, 45] mm. Major axis of the RA-SVC junction was 15 [13, 17] and minor axis of the RA-SVC junction was 11 [9, 13]. The number of ablation points with VG SVC isolation was fewer than that for NVG SVC isolation (8 [5, 11.5] vs. 11.5 [8.8, 13.3]; p = 0.001). The procedure time of VG SVC isolation was greater than that of NVG SVC isolation (259 s [154, 379] vs. 167 s [115, 222]; p = 0.012). There were no significant differences in the complication rates.

CONCLUSIONS

VG SVC isolation reduced the number of ablation points compared with NVG SVC isolation.

Empirical superior vena cava electrical isolation guided by quantitative ablation index improves outcomes of radiofrequency catheter ablation for paroxysmal atrial fibrillation

BACKGROUND

The value of empirical superior vena cava isolation (SVCI) following pulmonary vein isolation (PVI) to improve the efficacy of radiofrequency catheter ablation (RFCA) for paroxysmal atrial fibrillation (PAF) remains controversial.

OBJECTIVE

To evaluate the efficacy and safety of quantitative ablation index (AI)-guided empirical SVCI, in addition to PVI, for patients with PAF.

METHODS

Patients with symptomatic PAF who underwent RFCA between October 2021 and May 2023 were retrospectively analysed. Patients were categorised into PVI-only group and PVI+SVCI group based on the intraoperative ablation strategy. RFCA was guided by quantitative AI in both groups. Regular clinical follow-ups were conducted to detect AF recurrence, defined as any episode of atrial fibrillation, atrial flutter or atrial tachycardia lasting >30 s.

RESULTS

A total of 246 patients were enrolled, with 108 patients in the PVI group and 138 patients in the PVI+SVCI group. Compared with the PVI group, patients in the PVI+SVCI group had a higher prevalence of coronary artery disease (p=0.04), stroke (p=0.02) and a smaller left atrial diameter (p<0.01). After a follow-up period of 16±6 months, the ablation success rate was significantly higher in the SVCI+PVI group compared with the PVI group (91.3% vs 81.5%, p=0.02). Multivariable logistic regression analysis indicated that SVCI was an independent predictor of reduced AF recurrence postablation (Relative Risk [RR] 0.4, 95% CI 0.19 to 0.90, p=0.026). No significant difference in complication rates was observed between the groups.

CONCLUSION

Quantitative AI-guided empirical SVCI, in addition to PVI, improves the success rate of RFCA for PAF without increasing the risk of complications.

Anatomical variation of femoral vessels and ultrasound-guided femoral vein puncture for catheter ablation of arrhythmias

OBJECTIVE

This study aims to investigate the anatomical variations in femoral vasculature and evaluate the clinical value of ultrasound-guided femoral vein puncture in catheter ablation procedures.

METHODS

In this retrospective analysis conducted from January 2023 to March 2023, we examined data from patients who underwent catheter ablation with ultrasound-guided femoral venipuncture. We evaluated the anatomy of the femoral vasculature at both high and low inguinal levels. Based on the relationship between the femoral vein and artery, we classified the anatomy into four types: Type I (vein parallel to artery without overlap), Type II (vein medial to artery with lumen overlap ≤50%), Type III (vein posterior to artery with lumen overlap > 50%), and Type IV (vein lateral to artery). Additionally, we assessed procedure-related vascular complications that required interventions or prolonged hospital stays.

RESULTS

A total of 254 patients were included in this study. At the upper inguinal level, most cases (92.5%) exhibited Type II, followed by Type I (6.5%), while Type III (0.6%) and IV (0.4%) were less common. At the lower inguinal level, Type II accounted for 70.7%, there was a significantly higher proportion of Type III (23.4%) and Type IV (5.9%). The overall complication rate was 0.4%, no pseudoaneurysm or hematoma was observed in our study.

CONCLUSION

Our study revealed significant anatomical variations in the relationship between the femoral vein and femoral artery. Ultrasound-guided femoral venipuncture significantly reduced vascular complication rate, making it a valuable tool for guiding puncture procedures.