Epicardial adipose tissue density predicts the presence of atrial fibrillation and its recurrence after catheter ablation: three-dimensional reconstructed image analysis.

Epicardial adipose tissue (EAT) induces inflammation in the atria and is associated with atrial fibrillation (AF). Several studies have examined the relationship between EAT volume (EAT-V) and density (EAT-D) and the presence of AF after catheter ablation. However, conclusions have been inconsistent. This study included 43 consecutive patients who underwent catheter ablation for AF and 30 control patients. EAT-V and EAT-D around the entire heart, entire atrium, left atrium (LA), and right atrium (RA) were measured in detail using reconstructed three-dimensional (3D) EAT images from dual-source computed tomography (CT). None of the measurements of EAT-V differed significantly between patients with AF and controls or between patients with recurrent AF and those without. On the other hand, all measurements of EAT-D were higher in patients with AF than in controls (entire atrium, p < 0.001; RA, p < 0.001; LA, p = 0.002). All EAT-D measurements were associated with the presence of AF. Among patients with AF who underwent ablation, all EAT-D measurements were higher in patients with recurrent AF than in those without. The difference was significant for EATRA-D (p = 0.032). All atrial EAT-D values predicted recurrent AF (EATRA-D: hazard ratio [HR], 1.208; 95% confidence interval [95% CI], 1.053-1.387; p = 0.007; EATLA-D: HR, 1.108; 95% CI 1.001-1.225; p = 0.047; EATatrial-D: HR, 1.174; 95% CI 1.040-1.325; p = 0.010). The most sensitive cutoffs for predicting recurrent AF were highly accurate for EATRA-D (area under the curve [AUC], 0.76; p < 0.01) and EATatrial-D (AUC = 0.75, p < 0.05), while the cutoff for EATLA-D had low accuracy (AUC, 0.65; p = 0.209). For predicting the presence of AF and recurrent AF after catheter ablation, 3D analysis of atrial EAT-D, rather than EAT-V, is useful.

Treatment with catheter ablation for patients with arrhythmia-induced cardiomyopathy caused by atrial fibrillation promises a good prognosis.

Clinical outcomes after catheter ablation in patients with reduced left ventricular (LV) ejection fraction (EF) and atrial fibrillation (AF) remain unclear. This study aimed to explore the clinical outcomes of patients with arrhythmia-induced cardiomyopathy (AIC) and the influence of pharmacological treatment on clinical outcomes in patients with AIC after the procedure. Ninety-six patients with AF with a reduced LVEF (LVEF < 50%, 66.7 ± 10.9 years; 72 males) underwent AF ablation. AIC was defined as patients whose LVEF recovered ≥ 50% after catheter ablation (n = 67) and patients whose LVEF remained reduced were defined as non-AIC (n = 29). During a median follow-up of 25 (13-40) months, Kaplan-Meier analysis demonstrated that patients with AIC were associated with less frequent cardiovascular death (p = 0.025) and hospitalization for worsening heart failure (p < 0.001) than those without AIC. Freedom from AF recurrence was similar between the two groups (p = 0.47). In multivariate analysis, the LV end-diastolic diameter (p = 0.0002) and the CHA2DS2-VASc scores (p = 0.0062) were independent predictors of AIC. Among the 67 patients with AIC, no significant differences in baseline characteristics, except for LV chamber size and cryoballoon use, were observed between patients with AIC with (n = 31) and without renin-angiotensin system (RAS) inhibitors (n = 36). In the Kaplan-Meier analysis, cardiovascular death, hospitalization for worsening heart failure, and AF recurrence after catheter ablation did not differ between patients treated with and without RAS inhibitors (all p > 0.05). Catheter ablation in patients with AIC due to AF is associated with a good post-procedural prognosis.IRB information The study was approved by the Research Ethics Committee of the University of Fukui (No. 20220151) and clinical trial registration (UMIN000050391).

Peri-procedural anticoagulation in patients with end-stage kidney disease undergoing atrial fibrillation ablation: results from the multicentre end-stage kidney disease-atrial fibrillation ablation registry.

AIMS: The optimal anticoagulation regimen in patients with end-stage kidney disease (ESKD) undergoing atrial fibrillation (AF) catheter ablation is unknown. We sought to describe the real-world practice of peri-procedural anticoagulation management in patients with ESKD undergoing AF ablation. METHODS AND RESULTS: Patients with ESKD on haemodialysis undergoing catheter ablation for AF in 12 referral centres in Japan were included. The international normalized ratio (INR) before and 1 and 3 months after ablation was collected. Peri-procedural major haemorrhagic events as defined by the International Society on Thrombosis and Haemostasis, as well as thromboembolic events, were adjudicated. A total of 347 procedures in 307 patients (67 ±9 years, 40% female) were included. Overall, INR values were grossly subtherapeutic [1.58 (interquartile range: 1.20-2.00) before ablation, 1.54 (1.22-2.02) at 1 month, and 1.22 (1.01-1.71) at 3 months]. Thirty-five patients (10%) suffered major complications, the majority of which was major bleeding (19 patients; 5.4%), including 11 cardiac tamponade (3.2%). There were two peri-procedural deaths (0.6%), both related to bleeding events. A pre-procedural INR value of 2.0 or higher was the only independent predictor of major bleeding [odds ratio, 3.3 (1.2-8.7), P = 0.018]. No cerebral or systemic thromboembolism occurred. CONCLUSION: Despite most patients with ESKD undergoing AF ablation showing undertreatment with warfarin, major bleeding events are common while thromboembolic events are rare.

Contrast-enhanced computed tomography in the venous rather than the arterial phase is essential for the evaluation of the right phrenic nerve.

BACKGROUND: Preprocedural detection of the running course of the right pericardiophrenic bundles (PBs) is considered to be useful in preventing phrenic nerve (PN) injury during catheter ablation for atrial fibrillation (AF). However, previous studies using the arterial phase of contrast-enhanced computed tomography (CT) reported a relatively low right PBs detection rate. METHODS: This study included 63 patients with AF who underwent catheter ablation and preoperative contrast-enhanced CT imaging of the venous and arterial phases (66.7 ± 10.2 years; 44 male). The venous phase of contrast-enhanced CT significantly improved the detection rate of PBs compared to the arterial phase (96.8% vs. 60.3%, p < .001), and PBs were detected in the venous phase only in 23 (36.7%) patients. No significant differences were observed between the right PBs detection rate using non-contrast CT versus the arterial phase of contrast-enhanced CT (p = .37). Patients without visualization of the right PBs during the arterial phase had a higher frequency of chronic heart failure (p = .0083), lower left ventricular ejection fraction (p = .021), and a higher CHADS2 score (p = .048) than those with visualization. In five patients whose right PBs could only be detected during the venous phase of contrast-enhanced CT, the reconstructed running course of the right PBs corresponded with the PN generated by electrical high-output pacing. CONCLUSION: Contrast-enhanced CT images of the venous phase, rather than the arterial phase, are useful in detecting the right PBs, especially in patients with heart failure or reduced left ventricular ejection fraction.

Low troponin I levels predict the presence of arrhythmia-induced cardiomyopathy in patients with atrial fibrillation and left ventricular systolic dysfunction.

Successful atrial fibrillation (AF) ablation can improve reduced left ventricular ejection fraction (LVEF) with AF, which is defined as arrhythmia-induced cardiomyopathy (AIC). However, it is difficult to pre-procedurally predict the presence of AIC. We aimed to explore the pre-procedural predictors of AIC in patients with AF and reduced LVEF. This study included 60 patients with a reduced LVEF (LVEF < 50%; 69.1 ± 8.8 years; 45 men) who underwent successful AF ablation. Responders were defined as patients whose LVEF post-procedurally improved to the normal range (≥ 50%). Multivariate analysis revealed that the log-transformed pre-procedural troponin I (TnI) levels (odds ratio [OR] = 0.059; 95% confidence interval [CI] = 0.0052-0.42, p = 0.003) and age (OR = 0.91; 95% CI = 0.82-1.00, p = 0.044) were independent predictors of post-procedural LVEF recovery; further, low TnI levels (< 11.1 pg/ml) predicted LVEF recovery (sensitivity, 79.1%; specificity, 76.5%; positive predictive value, 89.5%; and negative predictive value, 59.1%). There were no significant differences in TnI levels between the baseline and 1 month after the procedure. However, four patients with high baseline TnI levels showed a > 50% reduction in the TnI levels post-procedurally, with three of these patients showing LVEF recovery. Low pre-procedural TnI levels can predict LVEF recovery after successful AF ablation in patients with reduced LVEF.

Subclinical sinus node dysfunction in patients with atrial fibrillation-Insight from ultrahigh-resolution mapping of human sinoatrial exits.

BACKGROUND: Even a short duration of paroxysmal episodes of atrial fibrillation (AF) is associated with sinus node (SN) remodeling and a reduced SN reserve or dysfunction. The number of earliest atrial activation sites (EASs) during sinus rhythm decreases according to the decrease in the SN reserve. OBJECTIVE: We sought to evaluate the EASs during sinus rhythm using an ultrahigh-density mapping system. METHODS: This study included 35 patients (supraventricular tachycardia [SVT]/paroxysmal atrial fibrillation [PAF]/persistent atrial fibrillation [PsAF] = 5/21/9) who underwent ultrahigh-resolution endocardial mapping of the SN area at rest and during ß-stimulation. The number of EASs was determined by the Lumipoint™ algorithm. RESULTS: The number of EASs was greatest in SVT patients both at rest (SVT/PAF/PsAF = 1.4 ± 0.8/1.0 ± 0/1.0 ± 0, p = .04) and during ß-stimulation (SVT/PAF/PsAF = 2.6 ± 1.0/1.3 ± 0.6/1.0 ± 0, p < .01). The number significantly increased with ß-stimulation as compared to baseline in the PAF patients (p = .02), but not in the PsAF patients. The brain natriuretic peptide (BNP) level was significantly higher in AF than SVT patients (SVT/PAF/PsAF = 12.3 [10.1-14.5]/25.7 [14.8-36.0]/73.4 [57.6-140] pg/ml, p < .01). In the PAF patients, the BNP level was significantly higher in those with unicentric EASs than multicentric EASs during ß-stimulation (28.1 [19.1-46.5] vs. 13.1 [9.4-26.9] pg/ml, p = .03), and the optimal cutoff point for the BNP level predicting unicentric EASs was 21.8 pg/ml (sensitivity 82.6%; specificity 85.7%). CONCLUSIONS: AF patients have a smaller number of EASs and poorer response to ß-stimulation than non-AF patients. An elevated BNP level might predict subclinical SN dysfunction in patients with PAF.

Safety and durability of cavo-tricuspid isthmus linear ablation in the current era: Single-center 9-year experience from 1078 procedures.

BACKGROUND: Cavo-tricuspid isthmus (CTI) linear ablation is performed not only for atrial flutter (AFL) but empirically during atrial fibrillation (AF) ablation in real-world practice.  PURPOSE: We sought to evaluate the safety and durability of the CTI ablation.  METHODS: This retrospective study included 1078 consecutive patients who underwent a CTI ablation. AFL was documented before or during the procedure in 249 (23.1%) patients, and an empirical CTI and AF ablation were performed in 829 (76.9%) patients.  RESULTS: CTI block was successfully created in 1051 (97.5%) patients with a 10.3 ± 6.6 min total radiofrequency time. Repeat procedures were performed for recurrent arrhythmias in 187 (17.3%) patients at a median of 11.0 (5.0-30.0) months postprocedure, and conduction resumption was identified in 68/174 (39.1%). Among those undergoing a CTI ablation with an AF ablation, the durability was significantly higher in those with than without documented AFL (78.1% vs. 58.2%, p = .031).  The total radiofrequency time was significantly shorter (9.0 ± 5.3 vs. 10.0 ± 6.4 [mins], p = .024) and durability significantly higher (78.1 vs. 58.7[%], p = .043) in the large-tip than irrigated-tip catheter group. Iatrogenic AFL was observed after the empiric CTI ablation in 11 (1.3%) patients. Procedure-related complications occurred in 15 (1.4%) patients. Eight patients experienced coronary artery spasms, including one with ventricular fibrillation following ST elevation on the ward. The other six patients experienced transient atrioventricular block and one experienced cardiac tamponade requiring drainage.  CONCLUSIONS: Despite a high acute CTI ablation success, the conduction block durability was relatively low after the empiric ablation. An empiric CTI ablation at the time of the AF ablation is not recommended.

Mapping and ablation of left atrial roof-dependent tachycardias using an ultra-high resolution mapping system.

BACKGROUND: Left atrial roof-dependent tachycardias (LARTs) are common macroreentrant atrial tachycardias (ATs). We sought to characterize clinical LARTs using an ultra-high resolution mapping system. METHODS: This study included 22 consecutive LARTs in 21 patients who underwent AT mapping/ablation using Rhythmia systems. RESULTS: Three, 13, 4, and 2 LART patients were cardiac intervention naïve (Group-A), post-roof line ablation (Group-B), post-atrial fibrillation ablation without linear ablation (Group-C), and post-cardiac surgery (Group-D), respectively. The mean AT cycle length was 244 ± 43 ms. Coronary sinus activation was proximal-to-distal or distal-to-proximal in 16 (72.7%) ATs. The activation map revealed 13 (59.1%) clockwise and 9 (40.9%) counter-clockwise LARTs. A 12-lead synchronous isoelectric interval was observed in 10/19 (52.6%) LARTs. The slow conduction area was identified on the LA roof, anterior/septal wall, and posterior wall in 18, 6, and 2 ATs, respectively. Twenty concomitant ATs among 13 procedures were also eliminated, and peri-mitral AT coexisted in 7 of 9 non-group-B patients. In group-B, the conduction gap was predominantly located on the mid-roof. Sustained LARTs were terminated by a single application and linear ablation in 6 (27.3%) and 9 (40.9%), while converting to other ATs in 7 (31.8%) LARTs. Complete linear block was created without any complications in all, however, ablation at the mid-posterior wall was required to achieve block in 4 (18.2%) procedures. During 14.0 (6.5-28.5) months of follow-up, 17 (81.0%) and 19 (90.5%) patients were free from any atrial tachyarrhythmias after single and last procedures. CONCLUSIONS: The LART mechanisms were distinct in individual patients, and elimination of all concomitant ATs was required for the management.

Cryoballoon left atrial roof ablation for persistent atrial fibrillation-Analysis with high-resolution mapping system.

BACKGROUND: Additional benefit of cryoballoon left atrial roof line ablation (CB-RA) beyond cryoballoon pulmonary vein isolation (CB-PVI) is suggested in patients with persistent atrial fibrillation (PsAF). We sought to investigate the feasibility of CB-RA for PsAF and to determine the ablation area. METHODS AND RESULTS: Fifty-three PsAF patients (67[58.5-75.5] years, 36 men, 11 longstanding PsAF) underwent CB-PVI. Subsequently, 44(83.0%) out of 53 patients underwent additional CB-RA. Voltage maps were created in all patients with a high-resolution mapping system. The total number and duration of CB-RAs were 3.9 ± 0.7 and 468 ± 84 s. LA roof areas were complete low voltage areas (LVAs) /scar in 37/44(84.1%) patients ("complete roof modification"). The normal LA posterior wall (LAPW) voltage area was 6.1(4.1-8.4) cm2 , and the %LAPW isolation area was 61.0(47.2-71.7)%. The %LAPW isolation area was significantly greater in CB-RA patients than those without (64.0[54.2-73.2] vs. 45.0[39.5-50.5]%, p = .041) despite significantly larger LAs in the former group. The %LAPW isolation area was significantly greater in patients with transverse LA diameters < 45 mm than those ≥ 45 mm (p < .0001). The single procedure 1-year AF freedom was 87.4% (22.5% on antiarrhythmic drug) and tended to be higher in CB-RA patients than those without. Among the 44 CB-RA patients, it was significantly higher in patients with a complete roof modification than those without (94.4% vs. 75.0%, p = .0049). One CB-RA patient experienced a delayed cardiac tamponade requiring drainage at 4-months post-procedure. CONCLUSIONS: CB-RA significantly expanded the LAPW isolation area, and a complete roof modification resulted in a high arrhythmia freedom in PsAF patients.

Conduction delay across the cavotricuspid isthmus block line caused by the gap near the inferior vena cava: the role of conduction block in the lower lateral right atrium.

The electrophysiological properties of the gap associated with the cavotricuspid isthmus (CTI) block line near the inferior vena cava (IVC) are not fully elucidated. Of 143 patients who underwent CTI block line ablation between September 2020 and April 2021, high-resolution CTI gap mapping was performed for 15 patients. Four patients were identified as having a gap near the IVC (IVC-side gap) despite wide double potentials (DPs) with > 90 ms intervals at the block line. Detailed gap mapping during coronary sinus ostial pacing was performed before and after touch-up ablation. CTI conduction delays caused by an IVC-side gap were classified into 3 patterns: (1) conduction delay at the IVC-side gap without detouring gap conduction, (2) detouring gap conduction due to intrinsic lower lateral right atrium (LLRA)-IVC functional block, and (3) detouring gap conduction due to LLRA-IVC conduction block created by lateral deviation of the CTI ablation line. In Pattern 2, IVC-side gap conduction traveled backward toward the crista terminalis below the LLRA-IVC junction and came back forward again above the border. One patient presented with a head-to-bottom activation pattern of the lateral right atrium (pseudo-CTI block). Pattern 3 was caused by lateral deviation of initial RF deliveries and presented with the same course as intrinsic LLRA-IVC functional block. All patients had wide DP intervals near the tricuspid annulus (mean, 112 ms) and just above the gap site (mean, 109 ms). An IVC-side gap associated with the CTI block line can present with various conduction delay patterns.

Evaluation of interatrial conduction pattern after pulmonary vein isolation using an ultrahigh-resolution electroanatomical mapping system.

Interatrial conduction consists of various muscular bundles, including the Bachmann bundle. In this study, we investigated interatrial activation patterns using ultrahigh-resolution left atrial endocardial mapping. This study investigated 58 patients who underwent catheter ablation of atrial arrhythmia via an ultrahigh-resolution mapping system (Rhythmia) at our hospital from May 2020 to January 2021. Left atrial voltage maps and activation maps were acquired after the ablation procedure during right atrial appendage (RAA) pacing. We defined left atrial breakout sites (LABSs) as centrifugal activation patterns shown by the LUMIPOINT Activation Search Tool. The distance between each LABS in the left atrial anterior wall and the superior border of the interatrial septum (DLABS-IAS) was measured on the shell of the electroanatomical map, and anterior LABSs were divided equally into roof- and septal-side groups. Fifty-three (91%) patients underwent cryoballoon pulmonary vein isolation. Ultrahigh-resolution left atrial mapping was successfully performed in all patients (6831 ± 2158 points). A total of 82 LABSs were identified in left atrial anterior wall; 34 patients had single LABS and 24 patients had dual LABSs. The mean DLABS-IAS was 10.3 ± 9.6 mm. Seven patients also exhibited posterior LABS near the interatrial raphe below the right inferior pulmonary vein. Patients with a single roof-side LABS had significantly shorter left atrial activation times than those with a single septal-side LABS (81.6 ± 13.2 ms vs. 93.5 ± 13.7 ms, p < 0.05). Interatrial conduction patterns during RAA pacing varied between patients and affected the left atrial activation time.

Declines in serum uric acid level after catheter ablation of atrial fibrillation.

BACKGROUND: Few studies have examined whether catheter ablation for AF patients improves biomarkers other than serum levels of brain natriuretic peptide (BNP) and renal function. This study was to explore whether catheter ablation for atrial fibrillation (AF) patients affects uric acid (UA), glucose and lipid metabolism. METHODS AND RESULTS: A total of 206 patients (66.6 ± 10.4 years; 132 men) who underwent initial AF ablation without changes to oral medications were included. Baseline BNP and UA levels significantly decreased at 1 year after ablation (p < 0.05 each). Changes in UA level correlated significantly with pre-procedural UA level (r = 0.57). In multivariable logistic regression modeling, pre-procedural UA level, persistent AF, and hemoglobin A1c (p < 0.05 each) were independent predictors of post-procedural UA level decline. Significant improvements in both persistent and paroxysmal AF patients were identified, and the magnitude of post-procedural serum UA level decline after ablation (ΔUA) was significantly greater in patients with persistent AF (0.8 ± 1.0 mg/dl) than in those with paroxysmal AF (0.2 ± 0.8 mg/dl, p < 0.001). Of the 48 patients with high UA level before procedure, 28 patients showed improvement in UA level to normal range. CONCLUSIONS: Catheter ablation for AF patients significantly improved serum UA levels without obvious influences of heart failure, renal function, or inflammation, suggesting that AF ablation may be effective for AF patients with hyperuricemia. Trial registration The study was approved by the Research Ethics Committee of University of Fukui (no. 20210132) and clinical trial registration (UMIN000044669).

Ultrahigh resolution electroanatomical mapping of the transverse conduction of the right atrial posterior wall in cases with and without typical atrial flutter.

INTRODUCTION: The right atrial posterior wall (RAPW) is known to form a conduction barrier during typical atrial flutter (AFL). We evaluated the transverse conduction properties of RAPW in patients with and without typical AFL using an ultrahigh resolution electroanatomical mapping system. METHODS AND RESULTS: This study included 41 patients who underwent catheter ablation of AF, typical or atypical AFL, in whom we performed RAPW mapping with an ultrahigh resolution mapping system during typical AFL and coronary sinus ostial pacing with three different pacing cycle lengths (PCLs) (1) PCL1: PCL within 40 ms of the AFL cycle length in patients with typical AFL or 250-300 ms for those without, (2) PCL2: 400 ms, (3) PCL3: PCL just faster than the sinus rate. Local RAPW conduction block was evaluated by propagation mapping and local double potentials separated by an isoelectric line. The functional block was defined as areas blocked during shorter PCLs but conductive during longer PCLs. The degree of blockade was calculated by dividing the blocked length by RAPW length (%blockade). Only two patients demonstrated a fixed complete RAPW block (100%, %blockade). Thirty-one patients demonstrated a partial block of RAPW, and the %blockade during PCL1-3 was 49.4 ± 19.8%, 39.5 ± 19.2%, and 35.0 ± 22.9% in this group, respectively. Functional block areas were frequently observed above the fixed block area adjacent to the RA-inferior vena cava junction. Transverse conduction block was more frequently observed in patients with typical AFL at any longitudinal level of RAPW. CONCLUSION: RAPW transverse conduction block is lower-side dominant and greater in patients with typical AFL than those without.

The mechanisms of left septal and anterior wall reentrant atrial tachycardias analyzed with ultrahigh resolution mapping: The role of functional block in the circuit.

BACKGROUND: Low voltage areas (LVAs) are most commonly observed on the left atrial (LA) septal/anterior wall. OBJECTIVE: We explored the mechanisms of LA septal/anterior wall reentrant tachycardias (LASARTs) using ultrahigh resolution mapping. METHODS: This study included seven consecutive LASARTs in six patients (75 [62.2-82.8] years, 4 women) who underwent atrial tachycardia (AT) mapping and ablation using Rhythmia systems. RESULTS: The AT cycle length was 266 (239-321) ms. During ATs, 11.0 (9.0-12.9) cm2 of LVAs were identified in all, and 0.8 (0.7-1.7) cm2 of dense scar was identified in four patients. Five ATs rotated around dense scar, while two rotated around functional linear block, which was confirmed during atrial pacing after AT termination. The AT circuit length was 8.7 ± 2.1 cm with a conduction velocity of 30.4 ± 3.7 cm/s. A median of 3.0 (2.0-4.0) slow conduction areas per circuit were identified, and 17/23 (73.9%) areas were present in LVAs, while they were at the border of the LVA and normal voltage areas in the remaining 6/23 (26.1%). Global activation histograms facilitated the identification of the critical isthmus in all. Tailor-made ablation at critical isthmuses successfully eliminated all ATs. However, one patient with AT related to functional linear block experienced recurrent AT related to dense scar, which progressed after the procedure. During a mean 14 ± 13 month follow-up after the last procedure, no patients experienced recurrent ATs without any complications. CONCLUSION: LASARTs consist of not only fixed conduction blocks but also functional conduction blocks. Ultrahigh resolution mapping is highly useful to decide the optimal tailor-made ablation strategy based on the mechanisms.

Cardiac rehabilitation after catheter ablation of atrial fibrillation in patients with left ventricular dysfunction.

Few studies have examined the efficacy and safety of cardiac rehabilitation in patients with atrial fibrillation (AF) who underwent AF ablation. We explored the feasibility of additional cardiac rehabilitation after AF ablation in patients with a reduced left ventricular ejection fraction (LVEF). Fifty-four patients with heart failure (HF) and a reduced LVEF (HFrEF) (LVEF < 50%; 67.1 ± 11.6 years; 43 men) who underwent initial AF ablation procedures were included. Fourteen (25.9%) patients underwent cardiac rehabilitation (rehabilitation-group) and the remaining 40 (74.1%) did not (non-rehabilitation-group) after the procedure. The rehabilitation-group patients were relatively older, more likely female (p = 0.024), and had more likely a history of an HF hospitalization (p < 0.01) and cardiac device implantation (p = 0.041). The baseline LVEF was significantly lower (p = 0.043) and brain natriuretic peptide (BNP) (p < 0.01) and C-reactive protein (CRP) (p < 0.01) values were significantly higher in the rehabilitation-group. The 6-min walk distance significantly improved after 21.4 ± 11.5 days of cardiac rehabilitation during hospitalization (226.1 ± 155.9 vs. 398.1 ± 77.5 m, p = 0.016) without any adverse events. During an 18.9 ± 6.3 month follow-up period, the freedom from AF recurrence (p = 0.52) and re-hospitalizations due to HF (p = 0.63) were similar between the 2 groups. No death or strokes were observed. During the follow-up period, the LVEF significantly improved similarly in both groups, and the change in the BNP and CRP values significantly decreased in the rehabilitation-group. Despite the rehabilitation-group patients having a more severe HF status, the clinical outcomes and AF freedom were similar between the 2 groups, suggesting the favorable impact of cardiac rehabilitation after AF ablation in HFrEF patients.

Discrepancy between CARTO and Rhythmia maps for defining the left atrial low-voltage areas in atrial fibrillation ablation.

Reported mapping procedures of left atrial (LA) low-voltage areas (LVAs) vary widely. This study aimed to compare the PentaRay®/CARTO®3 (PentaRay map) and Orion™/Rhythmia™ (Orion map) systems for LA voltage mapping. This study included 15 patients who underwent successful pulmonary vein isolation (PVI) for atrial fibrillation. After PVI, PentaRay and Orion maps created for all patients were compared. LVAs were defined as sites with ≥ 3 adjacent low-voltage points < 0.5 mV. LVAs were indicated in 8 (53%) among 15 patients, and the average values of the measured LVAs was comparable between the systems (PentaRay map = 5.4 ± 8.7 cm2; Orion map = 4.3 ± 6.4 cm2, p = 0.69). However, in 2 of 8 patients with LVAs, the Orion map indicated LVAs at the septum and posterolateral sites of the LA, respectively, whereas the PentaRay map indicated no LVAs. In those patients, sharp electrograms of > 0.5 mV were properly recorded at the septum and posterolateral sites during appropriate beats in the PentaRay map. The PentaRay map had a shorter procedure time than the Orion map (12 ± 3 min vs. 23 ± 8 min, respectively; p < 0.01). Our study results showed a discrepancy in the LVA evaluation between the PentaRay and Orion maps. In 2 of 15 patients, the Orion map indicated LVAs at the sites where > 0.5-mV electrograms were properly recorded in the PentaRay map.

Premature ventricular contraction originating from the distal left anterior fascicle: The usefulness of a multipolar catheter with small electrodes in mapping presystolic Purkinje potential and pace mapping.

Mapping and localizing presystolic Purkinje potentials are crucial for determining the optimal ablation site for fascicular premature ventricular contractions (PVCs). Here we present a case of PVCs originating from the distal left anterior fascicle (LAF). Activation mapping using a multipolar catheter with small electrodes demonstrated early presystolic Purkinje potentials during the PVCs. A moderately good pace-map match was also obtained near the successful ablation site. This case demonstrates the activation pattern of PVCs originating from the distal LAF and the usefulness of multipolar catheters with small electrodes for the mapping of fascicular PVCs.

The mechanisms of recurrent atrial arrhythmias after second-generation cryoballoon ablation.

BACKGROUND: In patients with paroxysmal atrial fibrillation (PAF), 10%-15% of patients require repeat procedures after second-generation cryoballoon pulmonary vein isolation (CB-PVI). We sought to explore the mechanisms of recurrences after cryoballoon ablation. METHODS: The data of 122 PAF patients who underwent second procedures for recurrent arrhythmias 7.0 (4.0-12.0) months after the CB-PVI were analyzed. During second procedures, non-PV AF foci were explored with isoproterenol, adenosine, and repetitive cardioversions. RESULTS: In total, 378/487 (77.6%) PVs remained isolated, and reconnections were not observed in any PVs in 59 (48.4%) patients. PV reconnections were associated with recurrences in 38 (31.1%) patients, of whom 33 (86.8%) had reconnections of at least 1 upper PV. In 6 (4.9%) patients, non-PV AF foci were identified in the upper PV antra where cryoballoons cannot isolate but within the circumferential radiofrequency PVI line. Non-PV AF foci were identified in the superior vena cava, right atrial body, left atrial body, and atrial septum in 28 (23.0%), 18 (14.7%), 4 (3.3%), and 5 (4.1%) patients, respectively. Twelve (9.8%) patients had multiple non-PV AF foci. Four (3.3%), 3 (2.4%), and 8 (6.5%) patients underwent second procedures for atrioventricular nodal reentrant tachycardia, atrial flutter, and atrial tachycardias. During 16.0 (8.0-24.0) months of follow-up, freedom from any atrial arrhythmia at 1 year and 2 years after the second procedure was 79.2% and 60.6%. Nineteen (15.5%) patients had antiarrhythmic drug therapy at the last follow-up. CONCLUSIONS: Our study suggested that improvement in the upper PV PVI durability, eliminating arrhythmogenic superior vena cavae and coexisting atrial arrhythmias, and bonus cryoballoon applications at PV antra might improve the single procedure outcome in cryoballoon ablation.

Phrenic nerve stimulation during right ventricular outflow tract pacing: A rare but possible complication.

Phrenic nerve stimulation (PNS) caused by a right ventricular (RV) lead is an uncommon complication of pacemaker implantations. We demonstrated a case of left PNS caused by an RV lead placed in the RV outflow tract (RVOT). The PNS was dependent on ventricular capture. This case highlighted a risk of PNS even during RVOT pacing.

Idiopathic right ventricular arrhythmias requiring additional ablation from the left-sided outflow tract: ECG characteristics and efficacy of an anatomical approach.

INTRODUCTION: Despite the characteristic electrocardiogram (ECG) findings of early activation during ventricular tachyarrhythmias (VAs) and/or excellent pacemapping in the right ventricular outflow tract (RVOT), some VAs may require additional, left-sided ablation for a cure. METHODS AND RESULTS: This study included five patients with idiopathic VAs whose QRS morphologies were highly suggestive of an RVOT origin. The ECG characteristics and intracardiac electrocardiograms during catheter ablation were assessed. In all patients, the clinical VAs had an LBBB QRS morphology and inferior axis with a precordial R/S transition through leads V3-V5, and negative components in lead I. The earliest activation during the VAs (local electrogram-QRS interval = -34 ± 6.8 ms) and excellent pacemapping were obtained at the posterior portion of the RVOT just beneath the pulmonary valve. However, ablation at those sites failed, and the QRS morphology of the VAs changed. During left-sided OT mapping, the earliest activation was found at sites just contralateral to the initially ablated sites of the RVOT (junction of the left and right coronary cusps = 2, left coronary cusp = 3). In spite of the late activation time and poor pacemapping scores, catheter ablation at those sites cured the VAs. Those successful sites were also near the transitional zone from the great cardiac vein to the anterior interventricular vein (GCV-AIV). CONCLUSIONS: Some VAs, highly suggestive of having RVOT origins, require catheter ablation in the left-sided OT near the initially ablated RVOT site. Those VAs have the same ECG characteristics and might have intramural origins in the superobasal LV surrounded by the RVOT, LVOT, and GCV-AIV.