Epicardial Ventricular Tachycardia Ablation Guided by a Novel High-Resolution Contact Mapping System: A Multicenter Study

Cardioneuroablation Using Epicardial Pulsed Field Ablation for the Treatment of Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting millions of people worldwide. The cardiac autonomic nervous system (ANS) is widely recognized as playing a key role in both the initiation and propagation of AF. This paper reviews the background and development of a unique cardioneuroablation technique for the modulation of the cardiac ANS as a potential treatment for AF. The treatment uses pulsed electric field energy to selectively electroporate ANS structures on the epicardial surface of the heart. Insights from in vitro studies and electric field models are presented as well as data from both pre-clinical and early clinical studies.

Epicardial mapping and ablation for ventricular arrhythmias in experienced center without onsite cardiac surgery

Objective: Epicardial access is sometimes required to effectively treat ventricular arrhythmias, but it can be associated with increased risk of procedural complications needing surgical intervention. The present study aimed to evaluate the feasibility and safety of epicardial mapping/ablation in experienced center without onsite cardiac surgery.

Methods: Patients who had drug-refractory, recurrent ventricular arrhythmias were scheduled for catheter ablation. All operators (SC, JC, SB, BS) had at least fifty pericardial puncture experiences. Epicardial puncture and perioperative anticoagulation were carried out based on institutional protocol. Phrenic nerve was mapped by 3-D mapping system. Coronary anatomy was delineated by coronary angiography.

Results: A total of 44 patients (63.3 years, male 86.4%) received epicardial access. Of them 7 (15.9%) were scheduled for PVC ablation, 37 (84.1%) for VT ablation (ICM: 25%, NICM: 59.1%). Mean LVEF was 41.3%. Acute ablation success rate was 35 (79.5%). Procedural adverse events included: pericardial effusion occurred in 3 (6.8%) patients who all well treated with pericardial drainage; and pericardial tamponade in 1 (2.3%) patient requiring transfer to surgical intervention. No death, stroke, phrenic nerves palsy, or coronary artery injury were observed. Median hospitalization was 4 (3–6) days. Univariable analysis and ROC curve showed that patients’ age was a significant predictor of epicardial procedural complication (area under curve (AUC): 0.813, P = 0.041).

Conclusions: Guided by a tailored procedural protocol, the majority of the epicardial access related complications can be treated conservatively without needing onsite surgery. Older age is a risk factor associated with epicardial access related complications.

Epicardial Ventricular Tachycardia Ablation Guided by a Novel High-Resolution Contact Mapping System: A Multicenter Study

Background

Mapping using a multipolar catheter with small and closely spaced electrodes has been shown to improve the validity of electrograms to identify endocardial critical sites of reentry isthmus and foci of earliest activation. However, the feasibility, safety, and clinical outcome of using such technology to guide epicardial ventricular tachycardia (VT) ablation has not been reported.

Methods and Results

Thirty‐three consecutive patients from 5 high‐volume centers were studied. These patients had 43 epicardial maps using a novel 64‐pole mini‐basket catheter to guide VT ablation. Activation maps with 17 832 points per map (interquartile range: 7621–32 497 points per map) were acquired in 11 patients with tolerated VT (7 focal, 4 reentry). Substrate maps with 40149 points per map (interquartile range: 20926–49391 points per map) were acquired in 30 patients. Local abnormal ventricular activities were consistently demonstrated at the substrate regions of interest. Epicardial ablation was performed in 31 of 33 patients, with acute VT termination in 10 of 11 patients (91%). Complete elimination of local abnormal ventricular activities was achieved in 25 of 31 patients. At a median follow‐up of 10 months (interquartile range: 4–14 months), 64% (7/11) of patients who had acute termination of VT and 55% (11/20) of those who had substrate modification alone were free of VT. There was no immediate complication following epicardial procedure.

Conclusions

Epicardial VT ablation guided by a mini‐basket catheter is feasible and safe. Complete reentry VT circuits and foci of earliest activation were identified in all inducible stable VT. The longer term clinical outcome of ablation guided by this novel mapping technology utilizing small and closely spaced electrodes will have to be determined with a larger study.

High-resolution/Density Mapping in Patients with Atrial and Ventricular Arrhythmias

High-definition/ultra-high-definition mapping, owing to an impressive increase of the point density of electroanatomic maps, provides improved substrate characterization, better understanding of the arrhythmia mechanism, and a better selection of the ablation target in patients with atrial and ventricular arrhythmias. Despite the scarce comparative data on ablation results versus standard mapping, ultra-high-definition mapping is increasingly used by the electrophysiology community.