Catheter ablation of ventricular arrhythmias originating from the para‐Hisian region with reversed C‐curve technique

The comparison between the novel technique and conventional method in the catheter ablation of premature ventricular contractions originating from the free wall of tricuspid annulus

BACKGROUND

This study aimed to assess the safety and effectiveness of a novel technique for catheter ablation in patients with premature ventricular contraction (PVC) from the free wall of tricuspid annulus (TV).

HYPOTHESIS

We hypothesized that the novel technique is more efficacious than the traditional approach.

METHODS

We retrospectively investigated 59 consecutive patients with PVC originating from the free wall of TV between January 2013 and November 2021. The patients were divided into two groups: the reversed S-curve technique group (RST, n = 26) and the reversed C-curve technique group (RCT, n = 33). The RST under the support of a steerable sheath was used in RST group, while the RCT under the support of a nonsteerable sheath was used in the RCT group. Systematic mapping and radiofrequency ablation were preferentially performed under the valve in all patients.

RESULTS

Compared to the RCT group, total procedural time and fluoroscopic exposure time were significantly shorter in RST group. Two patients experienced cardiac tamponade in the RCT group, while no complications were observed in RST group (p = .498). The success rate was significantly higher in RST group compared to RCT group (81.9% vs. 100%, p = .029). Three patients in RCT group failed to ablate during the operation but were successfully ablated using the novel method. During regular follow-up, no patients in the RST group had a recurrence, while three patients in the RCT group did (p = .274).

CONCLUSIONS

It suggests that the reserved S-curve technique, supported by a steerable sheath, is a feasible and effective method for ablating PVC originating from the free wall of TV.

Catheter ablation of ventricular premature depolarizations originating from mid interventricular septum: Significance of electrocardiographic morphology for predicting origin

BACKGROUND

Ventricular premature depolarizations (VPDs) originating from the mid interventricular septum (IVS) adjacent to the atrioventricular annulus between the His bundle and coronary sinus ostium (mid IVS VPDs) have not been characterized.

OBJECTIVE

The aim of this study was to investigate the electrophysiological characteristics of mid IVS VPDs.

METHODS

Thirty-eight patients with mid IVS VPDs were enrolled. The VPDs were divided into different types according to precordial transition of the electrocardiogram (ECG) and the QRS morphology in lead V1.

RESULTS

4 types of VPDs were divided. The precordial transition zone appeared earlier and earlier from types 1 to 4. The notch in V1 moved gradually backwards, its amplitude gradually became higher, resulting in transition from left to right bundle branch block morphology in V1 from types 1 to 4. Based on activation and pace mapping, ablation response, and the 3830 electrode pacing morphology in the mid IVS, the 4 types of ECG morphology corresponded, respectively, to an origin in the right endocardial side, right/mid intramural region, left intramural region, and left endocardial side of the mid IVS. An intramural origin was identified for 50% of the VPDs. 89% of mid IVS VPDs could be eliminated. Bilateral ablation (waiting for delayed efficacy) or bipolar ablation was sometimes needed for intramural VPDs.

CONCLUSIONS

Mid IVS VPDs were found to have unique electrophysiological characteristics. The ECG characteristics of mid IVS VPDs was important in terms of prediction of its exact origin, the choice of ablation method, and the likelihood of treatment being successful.

Electrocardiographic and electrophysiological characteristics of idiopathic ventricular arrhythmias with acute successful ablation at the left ventricular basal inferoseptum recess near the mitral annulus

PURPOSE

We sought to clarify the electrocardiographic and electrophysiological characteristics of ventricular arrhythmias (VAs), including idiopathic ventricular tachycardia (VT) and premature ventricular contractions (PVCs), with acute successful radiofrequency catheter ablation (RFCA) at the left ventricular basal inferoseptum recess near the mitral annulus (LV-BIS-MA).

METHODS

Twenty-five patients with acute successful RFCA at the LV-BIS-MA were included in this study.

RESULTS

The S-wave amplitudes on lead III during VAs were 1.54 ± 0.38 mV, significantly larger than those on lead II (0.55 ± 0.19 mV) and aVF (1.04 ± 0.31 mV) (P < 0.01). Precordial R/S > 1 transition before lead V₂ and S-waves in lead V₆ was recorded in 100% and 48.0% of patients, respectively. The earliest bipolar activation preceded the QRS onset by 32.3 ± 11.5 ms. Pace mapping demonstrated perfect QRS morphology matching in only 56.0% of patients. The RFCA start-to-effect time was 10.2 ± 5.8 seconds (s) in 21 patients (84.0%). In the remaining 4 patients (16.0%), the mean duration of successful RFCA was not well determined due to the infrequent presence of clinical VAs during ablation. The trans-septal approach was utilized in all 25 cases. Intra-cardiac echocardiography (ICE) showed that the ablation catheter tip was underneath the anterior leaflet of the mitral valve via the reversed C-curve technique. Early (within 3 days) and late (1 year) recurrence rates were 4.0% (one patient) and 12.0% (three patients), respectively. No complications during RFCA or at the 1-year follow-up.

CONCLUSIONS

LV-BIS-MA VAs are a subgroup of idiopathic VAs with distinctive ECG and EP features. RFCA via a trans-septal approach using a reversed C-curve technique is effective for better identification and targeting of the areas of VAs origin, and ICE showed that the ablation catheter tip was underneath the anterior leaflet of the mitral valve.

Understanding the scope of intracardiac echocardiography in catheter ablation of ventricular arrhythmia

Over the last few decades, catheter ablation has emerged as the first-line treatment for ventricular arrhythmias. However, detailed knowledge of cardiac anatomy during the surgery remains the prerequisite for successful ablation. Intracardiac echocardiography (ICE) is a unique imaging technique, which provides real-time visualization of cardiac structures, and is superior to other imaging modalities in terms of precise display of cardiac tissue characteristics as well as the orientation of anatomical landmarks. This article aimed to introduce the various advantages and limitations of ICE in the ablation of ventricular arrhythmias.

Premature ventricular contractions with acute successful radiofrequency catheter ablation near the atrioventricular node using reversed C curve technique

Background

We sought to clarify the electrophysiological (EP) characteristics of premature ventricular contractions (PVCs) with acute successful radiofrequency catheter ablation (RFCA) near the atrioventricular node (AVN).

Methods and results

Eighteen patients with acute successful RFCA near the AVN were included in this study. Systematic mapping was performed with two mapping methods: antegrade mapping technique (group A) and reversed C curve mapping technique (group R). RFCA was preferentially performed underneath the tricuspid valve (TV) with reversed C curve technique in all patients. The a amplitude/v amplitude ratio during sinus rhythm in group A was significantly larger than in group B (0.19 ± 0.10 vs 0.06 ± 0.02, p < 0.01). The earliest bipolar activation preceded the QRS onset in group A was significantly smaller than in group R (19.6 ± 4.9 vs 24.4 ± 6.6 ms (ms), p < 0.01). Pace mapping in group A and group R demonstrated perfect QRS morphology (12/12) match only in 5.6% (one patient) and 16.7% (3 patients) of patients, respectively. The mean duration of successful RFCA was 8.2 ± 2.4 s in 13 patients (72.2%). Early (within 3 days) and late (one-year) recurrence rates were 5.6% (one patient) and 16.7% (3 patients), respectively. No atrioventricular block occurred during RFCA or the one-year follow up.

Conclusions

PVCs near the AVN are a subgroup of idiopathic PVCs with distinctive EP features. RFCA using reversed C curve technique is effective and safe for the acute elimination of these challenging AVN-PVCs.

A Systemic Mapping Approach for Right and Left Parahisian Ventricular Arrhythmias Ablation

Background

Catheter ablation for parahisian ventricular arrhythmias (PHVA) is technically challenging and associated with increased risks of atrioventricular block (AVB). We developed a systemic mapping approach to improve the efficacy and safety of PHVA ablation.

Methods

Forty-three patients (29 males; average age 65.8 ± 10.5 years) with PHVAs were enrolled. A systemic mapping approach comprising differential electrocardiogram, sequential mapping, and ablation beneath/above the septal leaflet of the tricuspid valve (SLTV) and at the neighboring/contralateral regions (the aortic root and sub-aortic valve region) was applied for PHVA. The effectiveness and safety of this approach was evaluated at 1 year's follow-up.

Results

Sequential ablation beneath the SLTV (B-SLTV) succeeded in 24 (66.7 %) of 36 with right PHVA and ablation above the SLTV succeeded in 6 of the remaining 12 with failed B-SLTV ablation. Target-His bundle (HB) distance &gt; 4.5 mm significantly predicted successful right PHVA ablation (OR 1.703; 95% CI 1.084–2.676, P = 0.02). “Seeming” right PHVA by electrocardiogram in 4 and apparent left PHVA in 3 was successfully ablated at the sub-aortic parahisian region. At 1 year's follow-up, 27 (75%) of 36 patients with right PHVA and 6 (85.7%) of 7 patients with left PHVA were free of PHVA recurrence off anti-arrhythmic drugs. The total success rate was 76.7% by using the systemic mapping approach for PHVA. One patient with A-SLTV ablation underwent pacemaker implantation due to complete AVB.

Conclusions

The systemic mapping approach was effective and safe for treating PHVA. The target-HB distance was a significant predictor for right PHVA ablation.

R/S Ratio in Lead III Predicts Successful Ablation of Ventricular Arrhythmias Originating in Para-Hisian Region

OBJECTIVES

The aim of this study was to investigate the electrocardiographic characteristics of ventricular arrhythmias (VAs) originating near the His bundle (HB) and use the R/S ratio in lead III (R_III/S_III ratio) to predict successful ablation of para-Hisian VAs.

BACKGROUND

Catheter ablation for idiopathic VAs near the HB is often challenging, and data are limited.

METHODS

The present study included 134 consecutive patients undergoing catheter ablation of para-Hisian VAs. The electrocardiographic characteristics in these patients were retrospectively evaluated with successful ablation and failed ablation.

RESULTS

Successful ablation was achieved in 115 (85.8%) of the 134 patients. There was no significant difference in QRS duration between the successful and the failed ablation groups. The ablation success rate was significantly lower for para-Hisian VAs with a predominantly positive R wave in lead III than those with a predominantly negative S wave in lead III. The significant factor associated with successful ablation was the R_III/S_III ratio. The R_III/S_III ratio ≤1.1 predicted the successful ablation of para-Hisian VAs with high sensitivity (80.9%) and specificity (94.7%). The R_III/S_III ratio of >1.2 had high sensitivity (100.0%) and specificity (82.8%) to predict the distance <5 mm from the site of origin of para-Hisian VAs to the site recording the largest HB potential.

CONCLUSIONS

The R_III/S_III ratio was a helpful predictor of the successful ablation of VAs originating in the vicinity of the HB. This may be useful for planning ablation of para-Hisian VAs and minimizing the risk of inadvertent atrioventricular block.