Difference in radiofrequency ablation profile between during sinus rhythm and atrial fibrillation: Considerations in this era of high-power short-duration strategy.

Background: The concept of ablation index (AI) was introduced to evaluate radiofrequency (RF) ablation lesions. It is calculated from power, contact force (CF), and RF duration. However, other factors may also affect the quality of ablation lesions. To examine the difference in RF lesions made during sinus rhythm (SR) and atrial fibrillation (AF). Methods: Sixty patients underwent index pulmonary vein isolation during SR (n = 30, SR group) or AF (n = 30, AF group). All ablations were performed with a power of 50 W, a targeted CF of 5-15 g, and AI of 400-450 using Thermocool Smarttouch SF. The CF, AI, RF duration, temperature rise (Δtemp), impedance drop (Δimp), and the CF stability of each ablation point quantified as the standard deviation of the CF (CF-SD) were compared between the two groups. Results: A total of 3579 ablation points were analyzed, which included 1618 and 1961 points in the SR and the AF groups, respectively. Power, average CF, RF duration per point, and the resultant AI (389 ± 59 vs. 388 ± 57) were similar for the two rhythms. However, differences were seen in the CF-SD (3.5 ± 2.2 vs. 3.8 ± 2.1 g, p < .01), Δtemp (3.8 ± 1.3 vs. 4.0 ± 1.3°C, p < .005), and Δimp (10.3 ± 5.8 vs. 9.4 ± 5.4 Ω, p < .005). Conclusions: Despite similar AI, various RF parameters differed according to the underlying atrial rhythm. Ablation delivered during SR demonstrated less CF variability and temperature increase and greater impedance drop than during AF.

Relationship between the atrial-activation pattern around the triangle of Koch and successful ablation sites in slow-fast atrioventricular nodal reentrant tachycardia.

Background: The precise details of atrial activation around the triangle of Koch (ToK) remain unknown. We evaluated the relationship between the atrial-activation pattern around the ToK and success sites for slow-pathway (SP) modification ablation in slow-fast atrioventricular reentrant tachycardia (AVNRT). Methods: Thirty patients with slow-fast AVNRT who underwent successful ablation were enrolled. Atrial activation around the ToK during sinus rhythm was investigated using ultra-high-density mapping pre-ablation. The relationships among features of atrial-activation pattern and success sites were examined. Results: Of 30 patients (22 cryoablation; 8 radiofrequency ablation), 26 patients had a collision site of two wavefronts of delayed atrial activation within ToK, indicating a success site. The activation-search function of Lumipoint software, which highlights only atrial activation with a spatiotemporal consistency, showed non-highlighted area on the tricuspid-annulus side of ToK. In 23 of the patients, a spiky potential was recorded at that collision site outside the Lumipoint-highlighted area. Fifteen cryoablation patients with a success site coincident with a collision site outside the Lumipoint-highlighted area had significantly more frequent disappearances of SP after initial cryoablation (46.7% vs. 0%, p = .029), fewer cryoablations (3.7 ± 1.8 vs. 5.3 ± 1.3, p = .045), and shorter procedure times (170 ± 57 vs. 228 ± 91 min, p = .082) compared to the seven cryoablation patients without such sites. Four patients had transient AV block by ablation inside the Lumipoint-highlighted area with fractionated signals, but no patient developed permanent AV block or recurrence post-procedure (median follow-up: 375 days). Conclusions: SP modification ablation at the collision site of atrial activation of the tricuspid-annulus side along with a spiky potential could provide a better outcome.

Incidence of phrenic nerve injury during pulmonary vein isolation using different cryoballoons: data from a large prospective ablation registry.

AIMS: Phrenic nerve injury (PNI) is the most common complication during cryoballoon ablation. Currently, two cryoballoon systems are available, yet the difference is unclear. We sought to compare the acute procedural efficacy and safety of the two cryoballoons. METHODS: This prospective observational study consisted of 2,555 consecutive atrial fibrillation (AF) patients undergoing pulmonary vein isolation (PVI) using either conventional (Arctic Front Advance) (AFA-CB) or novel cryoballoons (POLARx) (POLARx-CB) at 19 centers between January 2022 and October 2023. RESULTS: Among 2,555 patients (68.8 ± 10.9 years, 1,740 men, paroxysmal AF[PAF] 1,670 patients), PVIs were performed by the AFA-CB and POLARx-CB in 1,358 and 1,197 patients, respectively. Touch-up ablation was required in 299(11.7%) patients. The touch-up rate was significantly lower for POLARx-CB than AFA-CB (9.5% vs. 13.6%, p = 0.002), especially for right inferior PVs (RIPVs). The touch-up rate was significantly lower for PAF than non-PAF (8.8% vs. 17.2%, P < 0.001) and was similar between the two cryoballoons in non-PAF patients. Right PNI occurred in 64(2.5%) patients and 22(0.9%) were symptomatic. It occurred during the right superior PV (RSPV) ablation in 39(1.5%) patients. The incidence was significantly higher for POLARx-CB than AFA-CB (3.8% vs. 1.3%, P < 0.001) as was the incidence of symptomatic PNI (1.7% vs. 0.1%, P < 0.001). The difference was significant during RSPV (2.5% vs. 0.7%, P < 0.001) but not RIPV ablation. The PNI recovered more quickly for the AFA-CB than POLARx-CB. CONCLUSIONS: Our study demonstrated a significantly higher incidence of right PNI and lower touch-up rate for the POLARx-CB than AFA-CB in the real-world clinical practice.

Impact of nocturnal blood pressure dipping on recurrence of atrial fibrillation after pulmonary vein isolation.

Lack of the typical nocturnal blood pressure (BP) fall, i.e non-dipper, has been known as a cardiovascular risk. However, the influence of non-dipper on atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) has been unclear. We investigated the clinical impact of non-dipping as evaluated by 24-hour ambulatory BP monitoring on the long-term outcome of AF recurrence post-PVI in 76 AF patients with a history of increased BP. The PVI procedure was successful in all 76 patients (mean age, 66±9years; antihypertensive medication, 89%; non-paroxysmal AF, 24%). Twenty patients had AF recurrence during a median follow-up of 1138 days. There was no difference in BP levels between the AF recurrence and non-recurrence groups (average 24 h systolic BP:126 ± 17 vs.125 ± 14 mmHg; P = 0.84). On the other hand, the patients with non-dipper had a higher AF recurrence than those with dipper (38.9% vs.15.0%; P = 0.018). In Cox hazard analysis adjusted by age, non-paroxysmal AF and average 24-hr systolic BP level, the non-dipper was an independent predictor of AF recurrence (HR 2.78 [95%CI:1.05-7.34], P = 0.039). Non-dipper patients had a larger left atrial (LA) volume index than the dipper patients (45.9 ± 17.3 vs.38.3 ± 10.2 ml/m2, P = 0.037). Among the 58 patients who underwent high-density voltage mapping in LA, 11 patients had a low-voltage area (LVA) defined as an area with a bipolar voltage < 0.5 mV. However, there was no association of LVA with non-dipper or dipper (22.2% vs.16.1%, P = 0.555). Non-dipper is an independent predictor of AF recurrence post-PVI. Management of abnormal diurnal BP variation post-PVI may be important.

Phrenic nerve injury after atrial fibrillation ablation: different recovery courses among cryoballoon, laser balloon, and radiofrequency ablation.

BACKGROUND: 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. METHODS: 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 RESULTS: 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% and 71.5% in the CB group, 15.0% and 22.2% in the LB group, and 23.4% and 41.9% in the RF-SVC group, respectively). Persistent PNI after 12 months was observed in only seven patients in the CB group, one in the LB group, and four in the RF-SVC group, respectively. CONCLUSION: PNI rarely persists over 12 months after AF ablation; however, there is a difference in the timing of its recovery. PNI recovers quicker with cryoballoon ablation than with laser balloon ablation or radiofrequency ablation of the SVC.

Conduction time around the mitral valve annulus has the potential to rule out postablation perimitral atrial tachycardia.

INTRODUCTION: It would be helpful in determining ablation strategy if the occurrence of perimitral atrial tachycardia (PMAT) could be predicted in advance. We investigated whether estimated perimitral conduction time (E-PMCT), namely, twice the time between coronary sinus (CS) pacing and the ensuing wave-front collision at the opposite side of the mitral annulus, correlated with the cycle length of PMAT and could predict future PMAT. METHODS AND RESULTS: We retrospectively (retrospective cohort) and prospectively (validation cohort) investigated atrial fibrillation patients who had received pulmonary vein isolation (PVI) and in whom left atrial maps had been created during CS pacing. We calculated their E-PMCT. PMAT was observed either by provocation or during follow-up in 25, AT other than PMAT was observed in 24 (non-PMAT AT group), and 53 patients never displayed any AT (no-AT group) in the retrospective cohort. In the PMAT group of the retrospective cohort, a strong positive correlation was observed between the PMAT CL and E-PMCT (r = .85, p < 0.001). PMAT was never induced nor observed in patients with E-PMCT less than 176 ms, and the best cut-off value for PMAT was 180 ms by receiver-operating characteristic curve analysis. In the validation cohort of 76 patients, the cut-off value of the E-PMAT less than 180 ms predicted noninducibility of PMAT, with a sensitivity of 78.6%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 25.0%. CONCLUSION: Short E-PMCT may predict noninducibility of PMAT and guide a less invasive ablation strategy.

Adjunctive posterior wall isolation for the treatment of persistent and longstanding persistent atrial fibrillation (CORNERSTONE AF) trial: Design and rationale.

BACKGROUND: A left atrial posterior wall isolation (LAPWI) is one of the atrial fibrillation (AF) ablation strategies. HYPOTHESIS: We hypothesized that an additional empirical LAPWI would increase the freedom from recurrent atrial arrhythmias as compared to standard AF ablation in persistent AF patients. METHODS: The CORNERSTONE AF study is a prospective, randomized, multicenter study investigating patients with AF persisting for >7 days and <3 years undergoing first-time AF ablation. They will be randomized to pulmonary vein isolation (PVI) or PVI + LAPWI in a 1:1 manner. Although PVI can be performed with either radiofrequency catheters or cryoballoons, only radiofrequency catheters will be permitted to achieve LAPWIs. Additional focal ablation targeting non-pulmonary vein triggers will be allowed. A total of 516 patients will be enrolled in 17 centers between August 2022 and February 2024 based on the calculation with 80% power, considering the assumption that 65% and 75% of the PVI and PVI + LAPWI group patients will be free from atrial arrhythmia recurrence 18-months postprocedure (10% of dropout). The primary endpoint is freedom from documented atrial arrhythmias 18 months postsingle procedures. Clinical follow-up will include 7-day ambulatory electrocardiograms and routine outpatient consultations by electrophysiologists at 1, 3, 6, 9, 12, and 18 months postprocedure. RESULTS: As of August 2023, a total of 331 patients (68 ± 9 years, 270 men, 43 longstanding persistent AF) have been enrolled. CONCLUSIONS: The CORNERSTONE AF study is a prospective, randomized, multicenter trial designed to evaluate the efficacy and safety of an adjunctive empirical LAPWI following standard AF ablation in persistent AF patients.

Symptomatic periesophageal vagal nerve injury by different energy sources during atrial fibrillation ablation.

Background: Symptomatic gastric hypomotility (SGH) is a rare but major complication of atrial fibrillation (AF) ablation, but data on this are scarce. Objective: We compared the clinical course of SGH occurring with different energy sources. Methods: This multicenter study retrospectively collected the characteristics and clinical outcomes of patients with SGH after AF ablation. Results: The data of 93 patients (67.0 ± 11.2 years, 68 men, 52 paroxysmal AF) with SGH after AF ablation were collected from 23 cardiovascular centers. Left atrial (LA) ablation sets included pulmonary vein isolation (PVI) alone, a PVI plus a roof-line, and an LA posterior wall isolation in 42 (45.2%), 11 (11.8%), and 40 (43.0%) patients, respectively. LA ablation was performed by radiofrequency ablation, cryoballoon ablation, or both in 38 (40.8%), 38 (40.8%), and 17 (18.3%) patients, respectively. SGH diagnoses were confirmed at 2 (1-4) days post-procedure, and 28 (30.1%) patients required re-hospitalizations. Fasting was required in 81 (92.0%) patients for 4 (2.5-5) days; the total hospitalization duration was 11 [7-19.8] days. After conservative treatment, symptoms disappeared in 22.3% of patients at 1 month, 48.9% at 2 months, 57.6% at 3 months, 84.6% at 6 months, and 89.7% at 12 months, however, one patient required surgery after radiofrequency ablation. Symptoms persisted for >1-year post-procedure in 7 patients. The outcomes were similar regardless of the energy source and LA lesion set. Conclusions: The clinical course of SGH was similar regardless of the energy source. The diagnosis was often delayed, and most recovered within 6 months, yet could persist for over 1 year in 10%.

Surgical Excision of a Left Atrial Mobile Stalked Calcification Arising After Multiple Radiofrequency Ablations.

We report a rare case of a mobile ectopic calcification in the left atrium requiring surgical excision 9 years after multiple atrial fibrillation ablations. (Level of Difficulty: Intermediate.).

Differences between typical and reverse typical atrial flutter identified by ultrahigh resolution mapping.

BACKGROUND: Although atrial flutter (AFL) is a common arrhythmia that is based on a macro-reentrant tachycardia around the tricuspid annulus, the factors giving rise to typical AFL (t-AFL) versus reverse typical AFL (rt-AFL) are unknown. To investigate the difference between t-AFL and rt-AFL circuits using ultrahigh resolution mapping of the right atrium. METHODS: We investigated 30 isthmus-dependent AFL patients (mean age 71, 28 male) who underwent first-time cavo-tricuspid isthmus (CTI) ablation guided by Boston Scientific's Rhythmia mapping system and divided them into two groups: t-AFL (22 patients) and rt-AFL (8 patients). We compared the anatomy and electrophysiology of their reentrant circuits. RESULTS: Baseline patient characteristics, use of antiarrhythmic drugs, prevalence of atrial fibrillation, AFL cycle length (227.1 ± 21.4 vs. 245.5 ± 36.0 ms, p = .10), and CTI length (31.9 ± 8.3 vs. 31.1 ± 5.2 mm, p = .80) did not differ between the two groups. Functional block was observed at the crista terminalis in 16 patients and at the sinus venosus in 11. No functional block was observed in three patients, all of whom belonged to the rt-AFL group. That is, functional block was observed in 100% of the t-AFL group as opposed to 5/8 (62.5%) of the rt-AFL (p < .05). Slow conduction zones were frequently observed at the intra-atrial septum in the t-AFL group and at the CTI in the rt-AFL group. CONCLUSION: Mapping with ultrahigh-resolution mapping showed differences between t-AFL and rt-AFL in conduction properties in the right atrium and around the tricuspid valve, which suggested directional mechanisms.

Inflammatory process of the COVID-19 fulminant myocarditis in the multimodality imaging: a case report.

Background: Cardiac manifest of COVID-19 infection was widely reported. The pathophysiology is thought the combination of direct damage caused by viruses and myocardial inflammation caused by immune responses. We tracked the inflammatory process of fulminant myocarditis associated with COVID-19 infection using multi-modality imaging. Case Summary: A 49-year-old male with COVID-19 went into cardiac arrest from severe left ventricular dysfunction and cardiac tamponade. He was treated with steroids, remdesivir, and tocilizumab but failed to maintain circulation. He recovered with pericardiocentesis and veno-arterial extracorporeal membrane oxygenation in addition to the immune suppression treatment. In this case, a series of chest computed tomography (CT) was performed on Days 4, 7, and 18 and cardiac magnetic resonance (MR) on Days 21, 53, and 145. Discussion: Analysis of the inflammatory findings on CT in this case showed that intense inflammation around the pericardial space was observed at an early stage of the disease. Although inflammatory findings in the pericardial space and chemical markers had improved according to non-magnetic resonance imaging (MRI) tests, the MRI revealed a notable long inflammatory period more than 50 days.

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.

Impact of unipolar voltage criteria for left atrial posterior wall on atrial fibrillation recurrence after pulmonary vein isolation.

INTRODUCTION: Beyond pulmonary vein isolation (PVI), additional therapeutic strategies for atrial fibrillation (AF) have not been established. Remodeling of the left atrium (LA) could impact AF recurrence post-PVI. We investigated the impact of unipolar voltage (UV) criteria for the LA posterior wall (LA-PW) on AF recurrence post-PVI. METHODS: We reviewed the cases of 106 AF patients (mean age 63.8 years, nonparoxysmal AF: 59%) who underwent extensive encircling PVI by radiofrequency ablation guided by a 3-dimension mapping system, investigating the impact on AF recurrence of the UV criteria of the LA. RESULTS: Out of all patients, 26 patients had AF recurrence during post-PVI follow-up [median 603 days]. They showed a higher percentage of nonparoxysmal AF (80.8 vs. 52.5%, p = .011), longer AF duration (2.9 ± 2.7 vs. 1.0 ± 1.7 years, p = .002), and larger area size of UV < 2.0 mV in LA-PW (2.8 ± 1.8 vs. 1.0 ± 1.5 cm2 , p < .001) than those without recurrence. Cox Hazard analysis for AF recurrence adjusted by age, gender, AF duration, body mass index and left atrial volume index revealed that an area size over 2.0 cm2 of UV < 2.0 mV in LA-PW (HR 6.9 [95% CI:1.3-35.5], p = .021) posed independent risks for AF recurrence post-PVI. The atrial arrhythmia-free survival rate was higher in those with no area of UV < 3.0 mV in LA-PW compared to those with a sizable area (>2.0 cm2 ) of UV < 3.0 mV and <2.0 mV (95.0% vs. 74.2% vs. 57.1%, Log-Rank: p < .001). In the AF etiology of patients with AF recurrence, 9 of 14 patients who underwent the 2nd procedure had no PV reconnection, and 8 patients required the LA-PW isolation for their non-PV AF. CONCLUSION: UV criteria of LA-PW is a useful parameter for AF-recurrence post-PVI. Lower UV in LA-PW as an indication of electrical remodeling could indicate a higher risk of AF recurrence and the need for further therapeutic strategies.

Electrogram characteristics at successful cryoablation sites in slow-fast atrioventricular nodal reentrant tachycardia.

PURPOSE: Cryoablation is a safe alternative to radiofrequency (RF) ablation for slow-fast atrioventricular reentrant tachycardia (AVNRT); however, optimal electrogram parameters for site selection remain unknown. We retrospectively investigated local electrograms for slow pathway (SP) modification in cryoablation. METHODS: Forty-five consecutive patients with slow-fast AVNRT who underwent cryoablation using a 6-mm-tip catheter were enrolled. Electrogram parameters for sites of successful SP modification (success-sites) were investigated; these included the interval between atrial activation at His and the last deflection of SP potential, defined as the His(A)-SPP interval. In 8 patients, 3-dimensional mapping by multi-electrode catheter was performed pre-ablation for more detailed SP assessment. RESULTS: Twenty-seven of 45 patients had successful SP modification by 1 cycle of freeze-thaw-freeze cryoablation at a single site with a low amplitude and fragmented SP potential. Among a total of 76 cryoablation sites in all patients, the His(A)-SPP interval at success-sites (45 sites) was significantly longer than that at unsuccess-sites (31 sites) (86 ± 9 vs.78 ± 10 msec, p < 0.0001). The AV amplitude ratio was not significantly different between success-and unsuccess-sites (0.21 ± 0.22 vs.0.25 ± 0.23, p = 0.429). The cutoff value of the His(A)-SPP interval for successful cryoablation was 82 msec with a sensitivity of 0.67 and specificity of 0.71 (AUC: 0.739; 95%CI: 0.626-0.852; p < 0.0001). Three-dimensional mapping in all 8 patients showed that sites with the most delayed atrial activation and the last deflection of the fragmented SP potential within the Koch's triangle coincided with success-sites. CONCLUSION: A longer His(A)-SPP interval and fractionated SP potential were characteristics of successful cryoablation for SP modification in slow-fast AVNRT.

Treatment of atrial tachycardia arising after superior transseptal approach mitral valve surgery: Insights from ultra-high-density mapping to prevent atrioventricular block.

INTRODUCTION: Mitral valve surgery employing a superior transseptal approach (STA) is associated with arrhythmogenicity and intra-atrial conduction delay, despite being optimal for visualization of the surgical field. It is sometimes difficult to treat atrial tachycardias (AT) that arise after STA. To investigate AT circuits that arise after STA in detail in order to identify the optimal ablation line, using ultra-high-resolution mapping (UHRM). METHODS: We retrospectively analyzed 12 AT from 10 patients (median age 70 years, nine males) who had undergone STA surgery. The tachycardias were mapped using the Rhythmia mapping system (Boston Scientific, Natick, Massachusetts). RESULTS: The 12 STA-related AT (STA-AT) circuits were classifiable as follows according to location of the optimal ablation line: (1) peri-septal incision STA-AT (n = 3), (2) cavotricuspid isthmus (CTI) dependent STA-AT (n = 7), and (3) biatrial tachycardia (n = 2). Radiofrequency (RF) application terminated 11 of the 12 STA-AT. We found that difference in STA-AT circuit type was due to characteristics of the septal incision line made for STA. UHRM was important in identifying optimal ablation sites that did not create additional conduction disturbances in the right atrium (RA). CONCLUSIONS: ATs after STA involve complex arrhythmia circuits due to multiple and long incision lines in the RA. Accurate understanding of the arrhythmia circuit and sinus conduction in the RA after STA is recommended for treating post-surgical tachycardia in a minimally invasive manner.

Perimitral atrial tachycardias dependent on residual nonligament of Marshall conduction.

INTRODUCTION: Catheter ablation for perimitral atrial tachycardia (PMAT) that persists despite lateral mitral isthmus (LMI) ablation is challenging. The aim of this study was to identify the role of the ligament of Marshall (LOM) in PMATs that persist after LMI conduction block has been created, and evaluate the validity of ethanol infusion into the vein of Marshall (VOM) as treatment. METHODS AND RESULTS: Sixteen consecutive PMATs in 13 patients that persisted despite apparent LMI conduction block, which was confirmed by ultrahigh-resolution mapping and entrainment pacing along the mitral annulus, were analyzed. PMATs were classified into two types based on the location of the endocardial breakthrough site: those utilizing the LOM (n = 13), which had a breakthrough site along with the LOM, and those not utilizing the LOM (n = 3), which had a breakthrough site at an anterior or posterior side of the LOM. Of the 16 PMATs, 5 PMATs (31%) were not suitable for ethanol infusion into the VOM because the LOM was not involved in the tachycardia circuit or because of the anatomy of the VOM. Fourteen PMATs (88%) were successfully terminated solely by breakthrough site ablation. At a mean follow-up period of 12 ± 9 months, 10 (77%) patients have remained free from atrial tachyarrhythmias. CONCLUSION: In cases of PMAT following LMI ablation, epicardial conduction over the LMI can occur independently of the LOM. Ethanol infusion into the VOM in such cases would not abolish residual epicardial conduction. The anatomy of the VOM can also preclude the use of this method.

Association between pericoronary adipose tissue attenuation and outcome after second-generation cryoballoon ablation for atrial fibrillation.

OBJECTIVES: Previous studies reported the association between inflammation and atrial fibrillation (AF). Pericoronary adipose tissue (PCAT) attenuation, PCATA, on cardiac CT angiography (CTA) reflects pericoronary inflammation. We hypothesized that the PCATA predicts AF recurrence after cryoballoon ablation (CBA) for paroxysmal and persistent AF. METHODS: We studied 364 patients (median age, 65 years) with persistent (n = 41) and paroxysmal (n = 323) AF undergoing successful first-session second-generation CBA with pre-ablation cardiac CTA. Three-vessel (3V)-PCATA was defined as the mean CT attenuation value of PCAT of all three major coronary arteries. Predictors of AF recurrence during follow-up were evaluated. RESULTS: AF recurrence after the 3-month blanking period was detected in 90 patients (24.7%) during the median follow-up of 26 (interquartile range, 19-42) months. AF recurrence was associated with prior stroke and statin use, NT-proBNP and high-sensitivity cardiac troponin-I levels, left ventricular dimension, left atrial volume index (LAVI), 3V-PCATA, and early AF recurrence during the blanking period. On multivariable Cox proportional hazard analysis, prior stroke (hazard ratio [HR], 2.208, 95% confidence interval [CI], 1.166-4.180, p = 0.015), LAVI (HR, 1.030, 95% CI, 1.010-1.051, p = 0.003), 3V-PCATA (HR, 1.034, 95% CI, 1.001-1.069, p = 0.046), and early AF recurrence (HR, 2.858, 95% CI, 1.855-4.405, p < 0.001) remained statistically significant. CONCLUSION: Pre-ablation CTA-derived 3V-PCATA, representing pericoronary inflammation, was an independent predictor of recurrence after first-session AF ablation using a second-generation cryoballoon. ADVANCES IN KNOWLEDGE: Assessment of 3V-PCATA may identify patients at high risk of AF recurrence after CBA for AF.