Catheter Ablation Approach Targeting Epicardial Connections to the Right Pulmonary Vein Antrum Detected before Pulmonary Vein Isolation.

BACKGROUND: Epicardial connections from surrounding structures to the right pulmonary vein (PV) antrum impede PV isolation. OBJECTIVE: This study aimed to evaluate the efficacy of an ablation approach targeting epicardial connections for right PV isolation. METHODS: We prospectively enrolled 124 patients with atrial fibrillation undergoing initial PV isolation. We identified the activation breakthrough into the right PV antrum (BT-RPV) on the activation map created during high right atrial pacing before PV isolation. BT-RPV sites were targeted when right PV isolation was not achieved by wide antral circumferential ablation (WACA). RESULTS: BT-RPV was observed in 83 cases (67%). PV isolation was achieved by WACA in all 41 cases without BT-RPV. Among cases with BT-RPV, PV isolation was achieved by WACA in 48 cases when all BT-RPV sites were covered by the PV isolation line. Conversely, PV isolation was completed by WACA in only 5 out of 35 cases when not all BT-RPV sites were covered. In cases where WACA failed, 35 sites were targeted for BT-RPV ablation. Initial BT-RPV ablation led to PV isolation at 20 sites, while the remaining 15 BT-RPV sites required repeat BT-RPV ablation. The ablated area of successful BT-RPV ablation was 0.9 [0.6-1.2] cm2, corresponding to the area activated within 15 [14-16] ms after BT-RPV emergence. Ablating the area activated within 14 ms after BT-RPV emergence was associated with successful PV isolation (sensitivity 91% and specificity 100%). CONCLUSION: Ablation targeting BT-RPV sites is effective for right PV isolation. Extensive ablation is required to eliminate BT-RPV.

Characteristics of radiofrequency lesions in patients with symptomatic periesophageal vagal nerve injury after pulmonary vein isolation.

Background: Periesophageal vagal nerve injury (PNI) is an unpredictable and serious complication of atrial fibrillation (AF) ablation. We aimed to identify the factors associated with symptomatic PNI. Methods: This study included 1391 patients who underwent ablation index-guided pulmonary vein isolation (PVI) using the CARTO system. The target ablation index was set at 550, except for the left atrial (LA) posterior wall near the esophagus, where radiofrequency (RF) power and duration were limited. Ten patients (0.72%) were diagnosed with symptomatic PNI. We randomly selected 40 patients without PNI (1:4 ratio) matched based on age, sex, body mass index, LA diameter, type of AF, and esophageal location. We measured the shortest distance from the RF lesions to the esophagus (LED) and classified the RF lesions according to the LED into four groups: 0-5, 5-10, 10-15, and 15-20 mm. We conducted a comparative analysis of classified RF lesions between patients with PNI (n = 10) and those without (n = 40). Results: The contact force at LED 0-5 mm was significantly higher in patients with PNI than in those without (14.6 ± 1.7 vs. 12.0 ± 2.9 g; p = .01). Multivariate logistic analysis revealed that the independent factor for PNI was contact force at an LED of 0-5 mm (odds ratio: 1.506; 95% confidence interval: 1.053-2.153; p = .025). Conclusions: The symptomatic PNI was significantly associated with a higher contact force near the esophagus. Strategies for regulating contact force near the esophagus may aid in the prevention of PNI.

Clinical Impact of Preoperative Symptoms of Aortic Stenosis on Prognosis After Transcatheter Aortic Valve Replacement.

Background: The prognostic significance of different presentations of aortic stenosis (AS) remains unclear. Our aim was to analyze outcomes after transcatheter aortic valve replacement (TAVR) according to preoperative AS symptoms. Methods and Results: We retrospectively enrolled 369 consecutive patients (age 84.3±5.0 years, and 64% females) who underwent TAVR from 2014 to 2021. We divided them into 4 groups by the main preoperative symptom: asymptomatic (n=50), chest pain (n=46), heart failure (HF; n=240), and syncope (n=33). Post-TAVR rates of HF readmission, all-cause death and cardiac death were compared among the 4 groups. The 4 groups showed no significant trends in age, sex, stroke volume index, or echocardiography indices of AS severity. During a follow-up, the overall survival rate at 1 and 5 years after TAVR was 97% and 90% in the asymptomatic group, 96% and 69% in the chest pain group, 93% and 69% in the HF group, and 90% and 72% in the syncope group, respectively. HF and syncope symptom had significantly lower HF readmission or cardiac death-free survival at 5 years after TAVR (log-rank test P=0.038). In the Cox hazard multivariate analysis, preoperative syncope was an independent predictor of future HF readmission or cardiac death after TAVR (HR=9.87; 95% CI 1.67-97.2; P=0.035). Conclusions: AS patients with preoperative syncope or HF had worse outcomes after TAVR than those with angina or no symptoms.

A randomized controlled trial of the size-adjustable cryoballoon vs conventional cryoballoon for paroxysmal atrial fibrillation: The CONTRAST-CRYO II trial rationale and design.

Background: Pulmonary vein isolation (PVI) with cryoballoon technology is a well-established therapy for treatment of atrial fibrillation (AF). Recently, a size-adjustable cryoballoon (POLARxTM FIT) that enables delivery in a standard 28-mm or an expanded 31-mm size was introduced. Objective: The purpose of this study was to perform a randomized clinical trial to evaluate the safety and efficacy of this novel cryoballoon compared to the conventional cryoballoon. Methods: The CONTRAST-CRYO II trial is a multicenter, prospective, open-label, randomized controlled trial in which 214 patients with paroxysmal AF will be randomized 1:1 to cryoballoon ablation with either a conventional cryoballoon (Arctic Front AdvanceTM Pro) or a size-adjustable cryoballoon (POLARx FIT). The study was approved by the Institutional Review Boards at all investigational sites and has been registered in the UMIN Clinical Trials Registry (UMIN000052500). Results: The primary endpoint of this study will be the incidence of phrenic nerve injury. Secondary endpoints include procedural success, chronic success through 12 months, procedure-related adverse events, biophysiological parameters during applications for each pulmonary vein (PV), total procedural and fluoroscopy times, level of PVI and isolation area, and probability of non-PV foci initiating AF. Conclusion: The CONTRAST-CRYO II trial is a multicenter, prospective, randomized controlled trial designed to assess the safety and efficacy of the POLARx FIT vs the Arctic Front Advance Pro. The findings from this trial will provide additional utility data on the efficacy of the size-adjustable cryoballoon for isolating PVs in patients with paroxysmal AF.

[Right Atrial Myxoma After Catheter Ablation:Report of a Case].

An 81-year-old man underwent total arch replacement for thoracic aortic aneurysm 8 years ago and catheter ablation for paroxysmal atrial fibrillation 1 year ago. Transthoracic echocardiography revealed a mass in the right atrium, and the patient was admitted for close examination and treatment. Transesophageal echocardiography revealed a 23×17 mm large well-defined mass above the cavotricuspid isthmus. Two venous drainage cannulas were inserted directly to the superior vena cava and to the inferior vena cava via the right femoral vein, in order to avoid the direct contact with the right atrium prior to institution of cardiopulmonary bypass. The right atrial tumor was found attached to the cavotricuspid isthmus, and was resected together with the right atrial wall. Pathological examination showed myxomatous tissue. Postoperative course was uneventful. He was discharged 23 days after the operation.

Narrow QRS ectopy with concealed connections from a para-Hisian origin to the proximal left fascicles.

INTRODUCTION: Catheter ablation of ectopy originating from the vicinity of the His bundle can be challenging. METHODS AND RESULTS: We report a case of a 33-year-old man with narrow QRS ectopy with preferential conduction from a para-Hisian origin to the proximal left fascicles, which was successfully eliminated by radiofrequency ablation in the right coronary cusp, guided by ultrahigh-resolution mapping of the His bundle, bundle branch, and fascicular electrograms. CONCLUSION: Some narrow QRS ectopy may originate from the vicinity of the conduction system, instead of the "true" conduction system, and have concealed connections from its origin to the conduction system.

The optimal slow pathway ablation site in atrioventricular nodal reentrant tachycardia cases with an inferiorly located His bundle.

INTRODUCTION: The optimal slow pathway (SP) ablation site in cases with an inferiorly located His bundle (HIS) remains unclear. METHODS AND RESULTS: In 45 patients with atrioventricular nodal reentrant tachycardia, the relationship between the HIS location and successful SP ablation site was assessed in electroanatomical maps. We assessed the location of the SP ablation site relative to the bottom of the coronary sinus ostium in the superior-to-inferior (SPSI), anterior-to-posterior (SPAP), and right-to-left (SPRL) directions. The HIS location was assessed in the same manner. The HIS location in the superior-to-inferior direction (HISSI), SPSI, SPAP, and SPRL were 17.7 ± 6.4, 1.7 ± 6.4, 13.6 ± 12.3, and -1.0 ± 13.0 mm, respectively. The HISSI was positively correlated with SPSI (R2 = 0.62; P < .01) and SPAP (R2 = 0.22; P < .01), whereas it was not correlated with SPRL (R2 = 0.01; P = .65). The distance between the HIS and SP ablation site was 17.7 ± 6.4 mm and was not affected by the location of HIS. The ratio of the amplitudes of atrial and ventricular potential recorded at the SP ablation site did not differ between the high HIS group (HISSI ≥ 13 mm) and low HIS group (HISSI < 13 mm) (0.10 ± 0.06 vs. 0.10 ± 0.06; P = .38). CONCLUSION: In cases with an inferiorly located HIS, SP ablation should be performed at a lower and more posterior site than in typical cases.

Characteristics of two different cryoballoon systems for treatment of paroxysmal atrial fibrillation: study protocol for a multicenter randomized controlled trial (CONTRAST-CRYO Trial).

BACKGROUND: Single-shot pulmonary vein isolation (PVI) utilizing cryothermal energy is an effective and safe treatment for atrial fibrillation (AF) patients. A novel cryoballoon system, POLARx™, has been recently introduced. The aim of this study was to compare the efficacy, safety, and biophysical parameters of PVI between the novel cryoballoon system, POLARx™, and the standard cryoballoon system, Arctic Front Advance Pro™ (AFA-Pro), in patients with paroxysmal AF. METHODS: The CONTRAST-CRYO trial is a prospective, multicenter, open-label, randomized controlled study performed at seven large cardiac centers. This study was approved by the central ethics committee or the local ethics committee of each participating hospital and has been registered at UMIN Clinical Trials Registry (UMIN000049948). The trial will assign 200 patients with paroxysmal AF undergoing PVI to POLARx™ and AFA-Pro in a 1:1 randomization. The primary endpoint is the one-shot acute success rate of the right inferior pulmonary vein. Second endpoints include freedom from documented atrial fibrillation, atrial flutter, or atrial tachycardia without antiarrhythmic drugs at 12 months after the procedure, freedom from re-do procedures, the incidence of procedure-related adverse events, freezing duration, and the biophysical parameters during applications for each PV, total procedure and fluoroscopy time, and PVI durability during re-do procedures. CONCLUSION: The CONTRAST-CRYO trial is a prospective, multicenter, randomized study designed to elucidate the difference in the efficacy, safety, and biophysical parameters between POLARx™ and AFA-Pro in paroxysmal AF patients undergoing PVI. The findings from this trial may provide a valuable indication for selecting the optimal cryoballoon system. CLINICAL TRIAL REGISTRATION:  UMIN000049948.

A-V-V-A response to single atrial premature depolarization in a narrow QRS tachycardia: What is the mechanism?

We present an atypical response to single atrial premature depolarization (APD) in a long RP' tachycardia. APD advanced the His-bundle potential immediately after it and resulted in a VA block; however, tachycardia persisted and consequently exhibited an A-V-V-A response. We propose the mechanism for an A-V-V-A response to APD in a long RP' tachycardia.

[Surgical Treatment of the Perforation of the Right Ventricle and Diaphragm by a Permanent Pacing Lead:Report of a Case].

An 97-year-old woman was diagnosed with complete atrioventricular block and underwent pacemaker implantation( PMI). Three days after the PMI, computed tomography revealed cardiac perforation and migration of the lead to the abdominal cavity. Surgical procedure through median sternotomy was performed, and the penetrated lead was removed. The holes of the right ventricle and diaphragm were repaired. Abdominal organ was not injured. She was discharged 14 days after the surgical procedure.

Incidence, distribution, and electrogram characteristics of endocardial-epicardial connections identified by ultra-high-resolution mapping during a left atrial posterior wall isolation of atrial fibrillation.

PURPOSE: The left atrial posterior wall (LAPW) can be a target for atrial fibrillation (AF) catheter ablation but is sometimes difficult to completely isolate due to the presence of endocardial-epicardial connections. We aimed to investigate the incidence and distribution of epicardial residual connections (epi-RCs) and the electrogram characteristics at epi-RC sites during an initial LAPW isolation. METHODS: We retrospectively studied 102 AF patients who underwent LAPW mapping before and after a first-pass linear ablation along the superior and inferior LAPW (pre-ablation and post-ablation maps) using an ultra-high-resolution mapping system (Rhythmia, Boston Scientific). RESULTS: Epi-RCs were observed in 41 patients (40.2%) and were widely distributed in the middle LAPW area and surrounding it. The sites with epi-RCs had a higher bipolar voltage amplitude and greater number of fractionated components than those without (median, 1.09 mV vs. 0.83 mV and 3.9 vs. 3.4 on the pre-ablation map and 0.38 mV vs. 0.27 mV and 8.5 vs. 4.2 on the post-ablation map, respectively; P < 0.001). Receiver operating characteristic analyses demonstrated that the number of fractionated components on the post-ablation map had a larger area under the curve of 0.847 than the others, and the sensitivity and specificity for predicting epi-RCs were 95.4% and 62.1%, respectively, at an optimal cutoff of 5.0. CONCLUSIONS: Among the patients with epi-RCs after a first-pass LAPW linear ablation, areas with a greater number of fractionated components (> 5.0 on the post-ablation LAPW map) may have endocardial-epicardial connections and may be potential targets for touch-up ablation to eliminate the epi-RCs.

Ethanol infusion therapy for peri-mitral atrial tachycardia through the Marshall bundle with electrical irrelevance of left atrial appendage and mitral isthmus.

A 62-year-old man with a history of catheter ablation for atrial fibrillation and atrial tachycardia (AT) received a line of block of the mitral isthmus (MI) and electrical isolation of the left atrial appendage (LAA). Upon entrainment pacing, AT recurred and was diagnosed as peri-mitral AT (PMAT) with electrical irrelevance of MI, LAA, and left pulmonary vein, having a critical isthmus identified as Marshall bundle (MB). MB was then infused with ethanol, leading to the successful treatment of the PMAT.

Noncontact Charge Density Mapping-Guided Ablation of Persistent Atrial Fibrillation With a Multiple Trigger-Based Mechanism.

We present a case of radiofrequency catheter ablation of persistent atrial fibrillation (AF) with a trigger-based mechanism, guided by novel noncontact charge density mapping, which resulted in the simultaneous achievement of the termination of AF and complete elimination of multiple triggers that induced repeated recurrences of AF immediately after cardioversion. (Level of Difficulty: Advanced.).

Intra-septal radiofrequency ablation within the transseptal puncture hole targeting an interatrial connection during a bi-atrial tachycardia.

A 74-year-old man after multiple mitral valve surgeries underwent catheter ablation of a bi-atrial tachycardia (BiAT). Ultra-high resolution activation mapping exhibited a reentrant circuit propagating around the inferior to anterior mitral annulus and right atrial (RA) septum with two interatrial connections. At the transeptal puncture site, continuous fractionated electrograms were recorded during the BiAT, and entrainment pacing revealed a post-pacing interval similar to the tachycardia cycle length, which suggested that the interatrial conduction from the RA to the left atrium (LA) was located just at the transseptal puncture site. A radiofrequency application inside the transseptal puncture hole could successfully eliminate the BiAT. The ablation target for BiATs propagating around the mitral annulus and RA septum is generally the anatomical mitral isthmus (MI). Since the present case had multiple incisions on both the RA and LA septum due to mitral valve surgeries, there was the possibility of the occurrence of a BiAT including the RA and LA septum after performing an MI linear ablation. Therefore, the preferable ablation target for the BiAT in the present case appeared to be the interatrial connection. Ultra-high resolution detailed mapping not only on the atrial endocardium but also in the transseptal puncture hole may be useful for identifying a critical interatrial connection of BiAT circuits.

Catheter ablation of the left-sided variant of right top pulmonary vein in a case with persistent left superior vena cava.

A 50-year-old woman underwent catheter ablation for atrial fibrillation. Preoperative computed tomography revealed a left-sided variant of the right top pulmonary vein (PV) and a persistent left superior vena cava. The right top PV was successfully isolated through a wide antral circumferential ablation line simultaneously with the right PVs.

Unusual QRS complexes associated with the simultaneous presence of a right-sided accessory pathway, fasciculoventricular pathway, and incomplete right bundle branch block.

A 52-year-old man presented with delta waves on a body surface electrocardiogram, which suggested the presence of a right-sided accessory pathway (AP). Patients with right-sided APs generally have an rS pattern in leads V1-2, while he had an rS in lead V1 but an Rs in lead V2, which could not rule out the possibility of the presence of a septal AP or fasciculoventricular pathway (FVP). On the other hand, patients with septal APs or FVPs generally have a QS pattern in lead V1 instead of an rS pattern. An electrophysiological study demonstrated that the simultaneous presence of a right-sided posterolateral AP and FVP with incomplete right bundle branch block (ICRBBB) generated those unusual QRS complexes. The FVP arose distal to the site with ICRBBB, and the ICRBBB delayed the initiation of the FVP conduction. The delayed QS and Rs waves in leads V1-2 generated by the FVP conduction with ICRBBB appeared to produce rS and Rs patterns in leads V1-2, respectively. A radiofrequency application along the posterolateral tricuspid annulus eliminated the right-sided AP conduction. If the localization of APs based on the QRS morphology is difficult, multiple APs or an FVP with a conduction system disturbance should be noted. Learning objective: Patients with right-sided posterolateral accessory pathways (APs) generally have an rS pattern in lead V2, while patients with fasciculoventricular pathways (FVPs) generally have a QS pattern in lead V1. The present case with a suspected right-sided posterolateral AP had unusual QRS complexes, an rS in lead V1, Rs in lead V2, and monophasic R in leads V3-6, which were associated with the simultaneous presence of a right-sided posterolateral AP, FVP, and incomplete right bundle branch block.