Reversed U-curve mapping and ablation of the left pulmonic cusp for treatment of the left ventricular summit arrhythmias

Funding Acknowledgements

Type of funding sources: None.

Introduction

Catheter ablation (CA) of the left ventricular summit (LVS) arrhythmias can be challenging. Close proximity of the left pulmonic cusp (LPC) offers a unique opportunity for targeting the LVS region. Whether LPC can serve as a vantage point for mapping and CA of LVS premature ventricular contractions (PVC) and ventricular tachycardia (VT) has not yet been systematically evaluated.

Methods

This is a retrospective analysis of consecutive patients who underwent CA of LVS PVC/VT and concomitant mapping and/or ablation within the LPC using reversed U-curve technique. PVC/VT activation precocity was determined and CA (unipolar, sequential unipolar and/or bipolar ablation) was performed involving LPC when necessary.

Results

A total number of 18 patients (age 59±15 years, 10 females) were included in this study. LPC mapping using reversed U-curve was successful in 17 (94%) patients. An earliest PVC/VT activation was recorded in LPC in 7 (39%). No early activation in the LPC was found in 5 (28%) patients. Selective LPC ablation (24W, 206s) led to acute suppression with late VT recurrence in one patient, whereas LPC served as an additional ablation target for sequential CA (37±4W, 416±252s) in 11 (61%) patients. 6 (33%) patients required combined sequential unipolar and bipolar CA (37±8W, 690±248s) between LPC and adjacent LVOT and this approach led to PVC/VT elimination in 5 patients. There were no procedure-related complications. During follow up 4 (22%) patients required redo ablation. Ultimately clinical success was achieved in 14 (78%) patients.

Conclusions

LPC mapping of LVS PVC/VT using reversed U-curve is safe and can be helpful for determination of LVS arrhythmia site of origin. While LPC ablation alone is rarely successful in eliminating LVS arrhythmias, it can serve as an anatomical vantage point for additional ablation of LVS PVC/VT as a part of sequential unipolar or bipolar CA.

Right anterior ganglionated plexus ablation for the treatment of vagally-mediated atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein isolation (PVI) is a cornerstone for catheter ablation of atrial fibrillation (AF), however, exact mechanisms of PVI efficacy remain debatable. PVI is an invasive left-atrial procedure which may be associated with complications. It has been postulated that in patients with increased vagal tone AF can be treated by attenuation of parasympathetic drive to the heart using cardioneuroablation (CNA) by means of radiofrequency (RF) ablation of the ganglionated plexi, however, data in literature are lacking.

Objectives

To examine the mid-term efficacy of RF-CNA targeting the right anterior ganglionated plexus (RAGP) in the management of AF using right-atrial (RA) approach only.

Methods

We included consecutive 12 male patients (age 55±11) with vagally-mediated AF (decelaration capacity (DC) >7 ms, mean 11,2±3,7ms) who underwent RF-CNA of RAGP. RAGP was targeted anatomically at the septal area below superior vena cava (SVC) from RA only. The aim was to achieve ≥30% heart rate acceleration (HRA). The follow up consisted of regular visits combined with ECG conducted every 3 months and 24h or 7-day Holter ECG.

Results

The RF time was 126±61 sec, power - 34±7W and procedure time - 44±18 min. The ≥30% HRA was achieved in 7 (58%) patients (pre-RF vs post-RF: 58±7 bpm vs 80±9 bpm, p=0,0000013). There were no complications during procedures. The follow up lasted 11±6 months. All patients reported significant symptom improvement post-CNA. AF-free survival was significantly higher in patients with ≥30% HRA during RF-CNA (≥30% HRA vs <30% HRA, 60% vs 14%, log rank p=0,0203) Conclusions: Right atrial RF-CNA of RAGP can be effective in patients with vagally-mediated AF. Larger prospective studies are needed to confirm these preliminary findings.

Catheter ablation of atrial fibrillation without pulmonary vein isolation

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein isolation (PVI) is a cornerstone for catheter ablation (CA) of atrial fibrillation (AF), however, long-term efficacy of PVI is frequently below expectations. PVI is invasive, expensive and may be associated with devastating complications. It has been postulated that vagally-mediated AF can be treated by attenuation of parasympathetic drive to the heart using cardioneuroablation by means of radiofrequency CA (RFCA) of the right anterior ganglionated plexus (RAGP), however, data in literature and guidelines are lacking.

Purpose

To examine the efficacy of RFCA targeting RAGP without PVI in management of vagal AF.

Methods

We included consecutive 9 male patients with vagal AF who underwent RFCA of RAGP without PVI. RAGP was targeted anatomically from the right atrium (RA) at the postero-septal area below superior vena cava (SVC) and from the left atrium (LA) if needed. The aim was to achieve >30% increase in heart rate (HR) . The follow up consisted of regular visits and Holter ECG conducted every 3 months.

Results

A total number of 9 patients (age 52 ± 13) with vagally-mediated AF underwent RFCA of RAGP (mean RAGP RF time 147 ± 85, max power 34 ± 8W). The mean procedure time was 60 ± 29min. HR increase >30% was achieved in 8 (89%) patients (pre-RF vs post-RF: 58 ± 8bpm vs 87 ± 12bpm, p = 0.00002) . Transseptal  to reach RAGP also from the LA was needed in 2 (22%) patients. There were no major complications during the procedures. The follow up lasted 6 ± 2 months. Antiarrhythmic drugs were discontinued in 8 (89%) patients. There was 1 (11%) AF recurrence in the patient in whom targeted HR acceleration during RFCA was not achieved. B-blockers were administered in  6 (67%) patients due to increased HR and such treatment was well tolerated by all.

Conclusions

Catheter ablation of RAGP without performing PVI is feasible and can be effective in majority of patients with vagally-mediated AF. Increased HR after such cardioneuroablation can be well controlled using b-blockers and is usually associated with mild symptoms. The role of cardioneuroablation for treatment of vagally-mediated AF needs to be determined in prospective trials. Abstract Figure. Cardioneuroablation in vagal AF

Anterior position of dispersive patch for esophageal protection during atrial fibrillation ablation. A pilot feasibility study

Funding Acknowledgements

Type of funding sources: None.

Introduction

Ablation for atrial fibrillation (AF) carries a significant risk of esophageal injury. Current methods of esophageal protection are invasive, expensive and their cost-effectiveness can be questioned. Standard placement of dispersive patch (DP) at patient’s back exposes esophagus to radio-frequency (RF) current-mediated thermal injury and such complications as esophageal wall ulceration, peri-esophageal injury or life-threatening atrio-esophageal fistula. Redirecting RF current by DP repositioning to anterior chest can theoretically protect oesophagus from thermal injury, however, such an approach has not yet been investigated.

Aim

To determine feasibility of anterior DP position for treatment of AF using RF catheter ablation (RFCA)-based system.

Methods

We retrospectively analysed consecutive patients undergoing  RFCA-based pulmonary vein isolation (PVI) using multi-electrode PVAC catheter with DP located either in anterior or traditional-posterior position. Two additional patients underwent point-by-point RFCA and mapping of PV ostia with impedance measurements during RFCA performed using anterior and posterior DP positioning.

Results

62 patients (25 females, age 60 ± 12 years) underwent PVI using PVAC: 40 patients in posterior and 22 in anterior DP group. There were no major complications during procedures. There was no significant difference in AF recurrence rate between anterior and posterior DP groups during one-year follow up (log rank p = 0.065). In two additional consecutive patients (1 female, age 74 ± 2 years) undergoing point-by-point RFCA a total number of 30 measurements around PV ostia were performed. There was a significant difference between impedance values in anterior vs posterior DP positions (134 ± 7 Ω vs 122 ± 8 Ω, p = 0.0004).

Conclusions

Anterior position of dispersive electrode for PV isolation using RFCA-based systems is safe, feasible, atraumatic and is not associated with any additional cost. Apart from redirecting RF current away from the esophagus, anterior dispersive patch placement is associated with higher impedance values which can act as an additional protection. Possible prevention of esophageal complications using anterior dispersive patch positioning needs to be determined in prospective studies. Abstract Figure. AF-free survival and impedance

P1127Occurrence, management and outcomes of iatrogenic aortic dissections as a complication of catheter ablation. A multicenter study

Background

Data on occurrence, management and outcomes of iatrogenic aortic dissections (IAD) as a complication of catheter ablation (CA) do not exist.

Purpose

To evaluate multicenter data on occurrence, management and outcomes of IAD as a complication of CA.

Methods

Data on occurrence, management and outcomes of documented vascular dissections from 10 centers were evaluated.

Results

IADs occurred in 7 patients (2 females, age 63 ± 8 years). Indications for CA were frequent premature ventricular complexes (PVC)/ventricular tachycardia (VT) in 6 patients (86%) and left-sided accessory pathway in the remaining one (14%). Hypertension was most frequent comorbidity (4 pts, 57%).  All IADs occurred during retrograde advancement of ablation catheter. In the vast majority of patients creation of IAD during catheter advancement was not associated with any symptoms (6 pts, 86%). IAD was initially detected using trans-luminal angiogram in 5 (71%) and further confirmed using computed tomography (CT) (5 pts, 71%), conventional angiography (2 pts, 28%) and ultrasound (2 pts, 28%). One IAD was detected during CT scan performed for other indication after CA. There was one IAD-related death and IAD was evaluated post-mortem. Follow-up lasted 10 ± 19 months. Four patients were treated conservatively, one patient underwent descending aorta stenting and one femoral artery stenting.

Conclusions

IAD during CA is a rare but can be devastating. Early recognition can be difficult. Conservative management of IAD is an option of treatment.

133Bipolar ablation of refractory ventricular arrhythmias originating from the close proximity of His bundle

Introduction

Biophysics of bipolar radiofrequency catheter ablation (Bi-RFCA) suggest more condensed and selective lesion formation when compared to conventional-unipolar approach. Whether more selective Bi-RFCA can result in safe and effective ablation of arrhythmic substrates in close proximity of His bundle has not been investigated so far.

Purpose

To determine feasibility and effectiveness of Bi-RFCA in His bundle area.

Methods

Consecutive patients after failed unipolar ablation for symptomatic premature ventricular complexes (PVC) or ventricular tachycardia (VT) originating from the vincity of His bundle underwent Bi-RFCA.

Results

We ultimately enrolled 8 patients (2 females, age 60 ± 15 years) to undergo Bi-RFCA of PVC/VT. Previous pharmacological treatment consisting of at least one antiarrhythmic drug and conventional catheter ablation failed in all. Bi-RFCA using open-irrigated and non-irrigated ablation catheters (AC) was delivered from two earliest PVC/VT activation sites located in the vincity of His bundle (Figure, panels A-B). A total number of 93 bipolar applications were delivered (mean bipolar RF time 508 ± 565s, mean power 35 ± 13W, mean impedance 163 ± 18Ω). Transient conduction disturbances occurred in 2 patients and were associated with mechanical compression of conduction system. No persistent conduction disturbances occurred. Bipolar RFCA led to acute elimination of PVC/VT in 6 (75%) patients. Follow up lasted 11 ± 5 months: two patients underwent repeat procedure using dual-irrigated Bi-RFCA, there was no VT recurrence and 72% PVC burden reduction was achieved (16200 ± 11600 pre-ablation vs 4500 ± 6200 post-ablation PVC/day, p = 0,035) (Figure, panel C).

Conclusion

Bi-RFCA performed in proximity of His bundle can be safe and effective in majority of patients.

Abstract Figure. Bipolar ablation of parahisian PVC/VT