BACKGROUND:Pulmonary vein (PV) isolation is a well-established and effective treatment for paroxysmal atrial fibrillation (AF). However, in some patients, AF recurrence is driven by non-PV triggers. Identifying these triggers is crucial for achieving long-term ablation success, but their localization can be challenging. CASE SUMMARY:This report presents the case of paroxysmal AF in which the combined use of self-reference mapping and atrial pace mapping using Intracardiac Pace Match Scoring (iPASO) enabled successful identification and ablation of multiple non-PV triggers, resulting in a satisfactory outcome. DISCUSSION:To the best of our knowledge, this is the first reported case in which multiple non-PV triggers were successfully eliminated through the combined use of self-reference mapping and iPASO mapping. TAKE-HOME MESSAGE:A multimodal approach, combining self-reference mapping and iPASO mapping, may be a useful strategy for identifying and managing non-PV triggers in clinical practice.

BACKGROUND:Pulsed-field ablation (PFA) has emerged as a novel energy source for pulmonary vein isolation in atrial fibrillation. Although generally safe, rare complications may occur during catheter manipulation in challenging pulmonary veins. CASE SUMMARY:A 71-year-old man underwent PFA with a circular-array catheter for paroxysmal atrial fibrillation. Echocardiography showed preserved left ventricular systolic function and a left atrial diameter of 39 mm. The right inferior pulmonary vein (RIPV) measured 15 mm at the ostium but bifurcated immediately, complicating catheter advancement. During circular-array catheter manipulation in RIPV, oxygen desaturation occurred, requiring endotracheal intubation. Hemoptysis developed, and bronchoscopy revealed bleeding from the right-lower-lobe bronchus, suggesting RIPV perforation. Idarucizumab and protamine were administered, and contrast-enhanced computed tomography confirmed extravasation. Bleeding resolved with supportive care, and the patient was discharged after 13 days. DISCUSSION:This case highlights a rare but serious complication associated with challenging RIPV anatomy during PFA. TAKE-HOME MESSAGE:Careful manipulation of a guidewire and a circular-array catheter is essential in narrow, branching pulmonary vein to prevent vascular injury.

BACKGROUND:Phrenic nerve injury (PNI) remains a clinically relevant complication of atrial fibrillation (AF) ablation, and contemporary device-specific risk and recovery data are limited. OBJECTIVE:We analyzed a large multicenter database to compare PNI incidence across device platforms. METHODS:This prospective observational study consisted of 19,764 consecutive AF ablations at 20 centers between January 2022 and November 2025. PNI was defined as elevation of the right hemidiaphragm on the next-day post-procedural chest X-ray. RESULTS:PNI occurred in 202 patients; 24 were attributed to radiofrequency ablation (RFA) and 178 to non-RFA during right superior or inferior pulmonary vein (RSPV/RIPV) isolation (Arctic Front Advance [AFA] 43, POLARx 62, POLARx FIT 69, laser balloon 1, hot balloon 2, and pulsed field ablation (1). Cryoballoon-related PNI incidence differed by platform (AFA 1.7% vs. POLARx 4.1% versus POLARx FIT 4.2%; overall P<0.001), with Holm-adjusted differences for AFA versus POLARx/POLARx FIT (both P<0.001). In the cryoballoon cohort, younger age (odds ratio [OR] 0.98), female sex (OR 1.94), lower body mass index (BMI) (OR 0.94), deep sedation/general anesthesia (OR 2.0, vs. light sedation), and POLARx/POLARx FIT use (OR 2.43/2.72, vs. AFA) were independently associated with PNI. Overall recovery was observed in 187/202 (92.6%). Recovery curves differed by presumed injury site (p = 0.006), with faster recovery for RSPV- (vs. RIPV-related PNI); RFA-related PNI during superior vena cava/right atrial ablation tended to recover more slowly. CONCLUSION:The cryoballoon platform was associated with PNI risk, while most PNIs recovered; recovery time course varied by presumed injury site and BMI.

During circumferential ablation of the right pulmonary veins (PVs), high-power, short-duration (HPSD) ablation at the anterior wall of the right PVs, corresponding to the left atrial septal side, resulted in an abrupt impedance increase from 120 to 180 Ω, occurring 11 s after RF delivery initiation (A). After an abrupt impedance rise, withdrawal of the ablation catheter from the long sheath revealed a circumferential thrombus adhering directly above the irrigation holes at the catheter tip (B). The catheter tip after thrombus removal is shown in (C), and the ring-shaped thrombus that adhered to the catheter tip is displayed in (D).

BACKGROUND:Pulsed-field ablation (PFA) is a novel nonthermal technique that achieves myocardial ablation with high tissue selectivity and fewer complications than conventional thermal methods. Coronary vasospasm has been increasingly reported with the Farawave catheter, but data on the PulseSelect system are limited. CASE SUMMARY:A 67-year-old man with paroxysmal atrial fibrillation and atrial tachycardia (AT) underwent catheter ablation. Pulmonary vein isolation was successfully achieved with the PulseSelect system. Subsequent mapping localized the AT to the lateral tricuspid annulus. Radiofrequency ablation repeatedly terminated the AT but was followed by immediate reinduction, failing to provide durable elimination. PulseSelect PFA was then applied to the same site, resulting in immediate AT termination and complete noninducibility thereafter. However, repeat coronary angiography revealed 75% stenosis in the right coronary artery, consistent with vasospasm, which promptly resolved after intracoronary nitroglycerin administration. DISCUSSION:This case demonstrates that PFA-induced coronary vasospasm can also occur with the PulseSelect system, often without electrocardiographic changes, warranting careful coronary assessment during ablation near atrioventricular annuli. TAKE-HOME MESSAGE:When using the PulseSelect system for ablation of atrioventricular annulus-origin arrhythmias, silent coronary vasospasm can occur regardless of catheter design, necessitating vigilance near the coronary arteries.

Ablation using a cryoballoon can minimize the number of sheaths passing through a permanent inferior vena cava filter (pIVCF). Cryoballoon ablation with only a few sheaths can be safely and efficiently performed via the usual femoral vein approach in patients with atrial fibrillation and pIVCF.

BACKGROUND:Cryoballoon pulmonary vein (PV) isolation (PVI) requires PV occlusion, which can be challenging to the large PV. The non-occlusive separate freezing, which involves freezing the superior and inferior portions of the PV ostium without complete occlusion, is often useful in these situations. This study aimed to evaluate the efficacy and long-term results of the non-occlusive separate freezing technique and compare the treatment details of POLARx and Arctic Front Advance Pro (AFA-Pro). METHODS:Patients who underwent cryoballoon PVI using the non-occlusive separate freezing between September 2019 and April 2023 in our institution were analyzed and followed up for 1 year. Success rates of PVI by non-occlusive separate freezing and treatment outcomes were compared between POLARx and AFA-Pro. The 1-year arrhythmia-free survival was also evaluated. RESULTS:Overall, 135 PVs were analyzed (POLARx, n = 63; and AFA-Pro, n = 72). The success rates of PVI for the POLARx and AFA-Pro were 55/63 (87.3%) and 52/72 (72.2%), p = 0.04. The nadir temperatures for the POLARx and AFA-Pro were -52.2 ± 4.7°C and -42.4 ± 7.4°C, p < 0.001. No phrenic nerve injury occurred in either group, but two cases of gastric hypomotility were observed using POLARx. The 1-year arrhythmia-free survival rates for POLARx and AFA-Pro were 86.4% and 81.2%, p = 0.47. CONCLUSIONS:The success rate of PVI using the non-occlusive separate freezing technique was approximately 80% and was significantly higher with POLARx than with AFA-Pro. The 1-year arrhythmia-free survival rate was not significantly different.

BACKGROUND:The novel POLARx cryoballoon ablation (CBA) system offers enhanced cooling properties for the treatment of atrial fibrillation (AF); however, these capabilities may damage adjacent tissues. This study aimed to assess the prevalence and predictors of gastric hypomotility (GH) in patients undergoing pulmonary vein isolation (PVI) and left atrial (LA) roofline ablation using the POLARx. METHODS:Patients who underwent CBA for PVI using the POLARx system were included in this study. Additional LA roofline ablation was performed in patients with non-paroxysmal AF and paroxysmal AF with LA enlargement. GH occurrence was assessed postoperatively by esophagogastroscopy, and the distance between the esophagus and surrounding tissues were measured. RESULTS:Among the 61 patients who underwent PVI, 22 underwent additional LA roofline ablation. GH was confirmed in 12 patients (30.8%) who underwent PVI only and 12 patients (54.5%) who underwent additional LA roofline ablation. Symptomatic GH with acute gastric dilation occurred in three patients, all of whom had undergone roofline ablation. Multivariate analysis, a shorter distance between the esophagus and the midpoint of the vertebral body (odds ratio, 0.74; 95% confidence interval, 0.55-0.98; p = 0.04) was identified as the sole predictor of GH, with a cutoff of 20.0 mm (sensitivity, 80.0%; specificity, 81.8%). CONCLUSION:Adding LA roofline ablation to PVI using the POLARx may increase the risk of GH, particularly when the esophagus is in close proximity to the midpoint of the vertebral body.

Background:The efficacy of cryoballoon ablation (CBA) using a 28-mm or 31-mm cryoballoon for isolating the left common pulmonary vein (LCPV) remains poorly established. We aimed to evaluate procedural outcomes and long-term follow-up data of CBA for the LCPV using either POLARx with a fixed 28-mm cryoballoon or POLARx FIT with a size-adjustable 28-mm or 31-mm cryoballoon. Methods:Patients with LCPV who underwent CBA for atrial fibrillation using POLARx or POLARx FIT between January 2022 and April 2024 were retrospectively analyzed. Procedural outcomes and long-term follow-up data were compared between the POLARx and POLARx FIT groups. Results:Fifty-one patients (32 males [62.7%]; mean age, 66 ± 11.6 years) were analyzed. The POLARx group included 23 patients, and the POLARx FIT group included 28 patients. First-freeze pulmonary vein isolation (PVI) success was 1 (4.3%) versus 8 (28.6%) (p = 0.03), and radiofrequency touch-up ablation was required in 2 (8.7%) versus 0 patients (p = 0.2) in the POLARx and POLARx FIT groups, respectively. Nadir temperature was -53.6° ± 4.7°C versus -54.7° ± 5.6°C (p = 0.45); the number of applications was 3.2 ± 1 versus 2.3 ± 0.9 (p < 0.01); and total freezing time was 520.9 ± 164 s versus 377.7 ± 129.9 s (p < 0.01) for the POLARx and POLARx FIT groups, respectively. A single gastric hypomotility case was observed in the POLARx FIT group. The 1-year arrhythmia-free survival rates were 81.8% and 78.7% for the POLARx and POLARx FIT groups, respectively (p = 0.96). Conclusions:POLARx FIT was useful for LCPV isolation, with a higher first-freeze PVI success rate, fewer applications, and shorter total freezing time compared to POLARx.

BACKGROUND:An indicator of successful cryoballoon (CB)-assisted pulmonary vein (PV) isolation is complete PV occlusion. However, CBs may exhibit a weaker freezing effect on the equatorial plane. This study investigates the predictors of failed left superior PV (LSPV) isolation despite complete occlusion with novel CBs. METHODS:This retrospective analysis enrolled 300 consecutive patients who underwent first-time ablation with POLARx or POLARxFIT between November 2021 and October 2023. Of the total, complete occlusion of the LSPV was achieved in 200 patients. Patients in whom LSPV isolation was achieved with additional nonocclusive freezing of the LSPV roof due to nonisolation of LSPV despite complete occlusion (Group A) were compared with those in whom isolation was achieved with complete PV occlusion alone (Group B). RESULTS:Group A had a larger LSPV diameter (21.5 ± 4.6 mm vs. 18.8 ± 3.3 mm, p = 0.052), larger left atrial volume on CT (142.3 ± 47.8 cc vs. 117.8 ± 39.0 cc, p = 0.028), higher nadir temperature (-54.1 ± 5.1°C vs. -60.2 ± 4.4°C, p < 0.001), and smaller northern latitude of the balloon contact site on the LSPV roof side (20.9° ± 3.8° vs. 38.9° ± 6.7°, p < 0.001) compared with Group B. A 27.5° north latitude was observed in most of Group A (sensitivity, 100%; specificity, 96%). CONCLUSIONS:Adequate contact positioning of the northern hemisphere to the LSPV is critical for effective isolation, particularly when isolation is challenging despite complete occlusion. In such cases, nonocclusive cryoablation against the LSPV roof might be effective.

BACKGROUND:Evidence regarding the management of left atrial thrombi (LATs) is limited. OBJECTIVES:We aimed to investigate factors associated with subsequent thromboembolism in patients with LATs and explored potential management approaches. METHODS:This multicenter retrospective study consecutively enrolled patients who underwent morphological assessment of LAT using echocardiography. We evaluated associations between clinical and echocardiographic variables and the occurrence of symptomatic thromboembolism. RESULTS:Two hundred six patients from 15 centers were enrolled. During follow-up period after echocardiographic diagnosis (651 days; interquartile range 174-1316 days), 19 patients (9.2%) developed thromboembolism. Cox regression analysis identified 3 independent predictors of thromboembolism: LAT maximum length > 20 mm (hazard ratio [HR] 2.63; 95% confidence interval [CI] 1.03-6.68; P=.043), reduced left ventricular ejection fraction (≤40%) (HR 2.95; 95% CI 1.14-7.63; P=.026), and thrombus mobility (HR 3.40; 95% CI 1.27-9.11; P=.015). Patients with ≥2 of these factors (52 [25.2%]) were categorized as the high-risk group, while those with <2 factors (154 [74.8%]) formed the low-risk group. Patients in the high-risk group had a higher incidence of thromboembolism (12 [23.1%] vs 7 [4.5%]; P<.001), despite a higher proportion undergoing urgent surgical thrombectomy (UST; 9 [17.3%] vs 9 [5.8%]; P=.025) compared with the low-risk group. In high-risk patients, UST was associated with a significantly lower rate of adverse outcomes, including all-cause mortality, heart failure hospitalizations, major bleeding, and thromboembolisms, at 90 days (0% vs 35.6%; log-rank, P=.048). CONCLUSION:In patients with LATs, large thrombus size, reduced left ventricular ejection fraction, and thrombus mobility were associated with subsequent thromboembolism. UST was associated with fewer adverse clinical outcomes in patients with ≥2 risk factors.

BACKGROUND The anatomical approach for the management of para-Hisian ventricular arrhythmias (VAs) with QRS morphological changes after catheter ablation (CA) has not been well investigated. OBJECTIVE We aimed to evaluate the electrocardiographic and electrophysiological findings and ablation outcomes of paraHisian VAs with QRS morphological changes after CA. METHODS Of the 30 patients who underwent CA for para-Hisian VAs at 4 institutions, 10 (33%) had QRS morphological changes after ablation. All 10 patients underwent an anatomical approach, targeting the site anatomically opposite to the site where the QRS morphology had been changed by ablation. We investigated the safety and efficacy of the anatomical approach. RESULTS Of the 10 patients evaluated, the approach was switched from the right ventricular septum to the left ventricular septum/aortic root in 7 (70%) (RL group) whereas 3 (30%) underwent left-to-right switches (LR group). After CA, the precordial transition zone tended to be earlier in the RL group and later in the LR group. In the RL group, successful VA suppression was achieved, despite suboptimal pace map concordance from the left side or a relatively delayed earliest activation time. Of the 10 patients who underwent an anatomical approach, 8 (80%) had procedural success, and ablation was discontinued in 1 (10%) because of the risk of atrioventricular block. CONCLUSION The anatomical approach showed promising results regarding safety and efficacy. Therefore, it should be considered when QRS morphological changes are observed during or after CA of para-Hisian VAs.

IntroductionDual atrioventricular nodal non-reentrant tachycardia (DAVNNT) is a rare and challenging-to-diagnose arrhythmia, without previous reports associating it with a leftward inferior extension (LIE).MethodsDiagnosis was made using adenosine triphosphate (ATP) injection during atrial pacing in a suspected DAVNNT patient.ResultsAblation of the rightward inferior extension was unsuccessful in eliminating DAVNNT; however, subsequent ablation of the LIE successfully eradicated the arrhythmia.ConclusionThis unique case, marked by the first instance of DAVNNT caused by LIE, diagnosed through ATP injection, underscores the utility of this diagnostic approach and broadens the spectrum of our understanding and management of this condition.

BACKGROUND:The effectiveness of cryoballoon ablation (CBA) of the left atrial (LA) roof in addition to pulmonary vein isolation (PVI) using a novel cryoballoon catheter, POLARx, remains unclear. METHODS:This study compared the efficacy of LA roof line ablation and PVI using POLARx (Boston Scientific) or AFA-Pro (Medtronic) in 100 patients with persistent atrial fibrillation. The right superior pulmonary vein (PV) anchoring and raise-up techniques were consistently used for LA roof line ablation, and rapid right ventricular pacing was applied if the cryoballoon temperature did not reach -40°C. RESULTS:Complete conduction block at the LA roof could be obtained in all patients with POLARx and in 98.0% of patients with AFA-Pro. Rapid right ventricular pacing was needed in 64.0% of patients with AFA-Pro and in no patients with POLARx. During LA roof line ablation, the nadir cryoballoon temperature was significantly lower with POLARx than with AFA-Pro (right: -54.2°C ± 4.4°C vs. -46.0°C ± 5.4°C; central: -56.8°C ± 4.4°C vs. -45.7°C ± 4.8°C; left: -56.1°C ± 4.3°C vs. -46.1°C ± 5.7°C), and the cryoballoon temperature reached -40°C earlier with POLARx than with AFA-Pro (right: 30.8 ± 7.4 s vs. 74.1 ± 37.7 s; central: 28.2 ± 5.2 s vs. 62.9 ± 30.9 s; left: 29.8 ± 5.8 s vs. 69.6 ± 40.7 s). CONCLUSION:The nadir cryoballoon temperature with POLARx was approximately 10°C lower than with AFA-Pro, consistently dropping below -40°C during LA roof line CBA. Thus, a complete conduction block of the LA roof line can be easily accomplished using right superior PV anchoring and the raise-up techniques without the need for rapid right ventricular pacing with POLARx.

BACKGROUND:Safety data of the latest radiofrequency (RF) technologies during atrial fibrillation (AF) ablation in real-world clinical practice are limited. OBJECTIVES:We sought to evaluate the acute procedural safety of the four latest ablation catheters commonly used for AF ablation. METHODS:A total of 3957 AF ablation procedures performed between January 2022 and December 2023 at 20 centers with either the THERMOCOOL SMARTTOUCH SF (STSF), TactiCath (TC), QDOT Micro (QDM), or TactiFlex (TF) were retrospectively analyzed. RESULTS:In total, QDM, STSF, TF, and TC were used in 343 (8.7%), 1793 (45.3%), 1121 (28.4%), and 700(17.7%) procedures. Among 2406 index procedures, electrical pulmonary vein isolations were successfully achieved in 99.5%. Despite similar total procedure times in the four groups, the total fluoroscopic time was significantly shorter for QDM/STSF with CARTO than TF/TC with EnSite (18.7 ± 14 vs. 27.6 ± 20.6 min, p < .001) and longest in the TF group. The incidence of cardiac tamponade was 0.7% (0.5% and 0.9% during index and redo procedures, 0.8% and 0.3% for paroxysmal and non-paroxysmal AF) and was significantly lower for QDM/STSF than TF/TC (0.2% vs. 1.1%, p = .008) and highest in the TF group. The incidence of cardiac tamponade was higher for TF than TC and STSF than QDM. In the multivariate analysis, TF/TC with EnSite was a significant independent predictor of cardiac tamponade during both the index (odds ratio [OR] = 4.8, 95% confidence interval [CI] = 1.3-17.5, p = .02) and all procedures (OR = 3.0, 95% CI = 1.3-7.2, p = .01). CONCLUSIONS:The incidence of cardiac tamponade and the fluoroscopic time during AF ablation significantly differed among the latest RF catheters and mapping systems in real-world clinical practice.

Phrenic nerve injury (PNI) is one of the common complications in atrial fibrillation (AF) ablation, which often recovers spontaneously. However, the course of its recovery has not been examined fully, especially in regard to the different ablation methods. We sought to compare the recovery course of PNI in cryoballoon, laser balloon, and radiofrequency ablation. This multicenter retrospective study analyzed 355 patients who suffered from PNI during AF ablation. PNI occurred during cryoballoon ablation (CB group) and laser balloon ablation (LB group) for a pulmonary vein isolation in 288 and 20 patients, and radiofrequency ablation for a superior vena cava (SVC) isolation (RF-SVC group) in 47 patients, respectively There was a significant difference in the estimated probability of PNI recovery after the procedure between the methods (p = 0.01). PNI recovered significantly earlier in the CB group, especially within 24 h and 3 months post-procedure (the percentage of the recovery within 24 h and 3 months: 49.7

Abstract Funding Acknowledgements Type of funding sources: None. Background In patients who are refractory to box isolation (BoxI) and have atrial fibrillation (AF) substrate in left atrial inferior wall (LAIW), LAIW isolation is effective, but the procedure is highly difficult because the connection between LAIW and coronary sinus (CS) is dense. In this study, we report four cases of persistent AF in which simultaneous isolation of LAIW and CS was so effective. Methods and Results Case 1 is a 76-year-old female with persistent AF who had undergone BoxI and failed mitral isthmus block (MIB) creation. However, AF and atrial tachycardia (AT) persisted. In the 4th session, chemical ablation of Marshall vein was performed, and AF/AT was terminated, and MIB was created. Thereafter, multiple ATs were still inducible by rapid atrial pacing. Because AT substrate seemed to be confined to LAIW, we attempted to isolate LAIW by performing linear ablation between the right inferior pulmonary vein (RIPV) and posteroseptal mitral annulus (MA) near CS ostium, and linear ablation parallel to CS along posterior MA. However, LAIW isolation could not be achieved. Finally, CS ostial ablation from right atrium (RA) succeeded in simultaneous isolation of LAIW and CS. CS burst pacing could induce AT confined to LAIW and CS although RA maintained sinus rhythm (SR). Rapid RA pacing could not induce AT/AF. Case 2 is a 78-year-old female with persistent AF who completed BoxI and MIB creation. Raid RA pacing induced AF. Because cycle length of LAIW was apparently shorter than RA, we attempted to isolate LAIW. Firstly, we performed linear ablation from RIPV ostium to posterior MA. During linear ablation, AF converted to AT, and finally RA returned to SR while AT was still sustained within LAIW and CS. This tachycardia was a reentrant tachycardia circling LAIW and CS. After this AT returned to SR by linear ablation within LAIW, LAIW and CS were not isolated during SR. CS ostial ablation from RA succeeded in simultaneous LAIW and CS isolation. Case 3 is a 74-year-old female with persistent AF refractory to BoxI. Although non-pulmonary vein (non-PV) trigger was documented in LAIW, the precise origin of non-PV trigger could not be identified due to infrequency. Case 4 is a 64-year-old male with persistent AF refractory to BoxI. He had undergone catheter ablation three times. Fractionation map showed that AF substrate was likely located in LAIW. Therefore, we attempted to isolate LAIW in Case 3 and 4. We performed MI ablation, linear ablation between RIPV ostium and posteroseptal MA, and CS ostial ablation from RA, which succeeded in simultaneous isolation of LAIW and CS in both cases. AF has never recurred in Case 1 and 2. SR could be maintained with antiarrhythmics in Case 3 and 4. Conclusions In patients with persistent AF refractory to BoxI, if LAIW has AF/AT substrate or non-PV triggers, simultaneous isolation of LAIW and CS may be a new therapeutic strategy. Simultaneous isolation of LAIW and CS requires ablation at CSos from RA.