Catheter Ablation for Paroxysmal Atrial Fibrillation With Sick Sinus Syndrome: Insights From the Kansai Plus Atrial Fibrillation Registry.

BACKGROUND: Coexisting sick sinus syndrome (SSS) is associated with both electrical and structural atrial remodelling in patients with atrial fibrillation (AF). Limited data are available concerning catheter ablation (CA) for AF in this condition. This study investigated the efficacy of CA as a curative therapy for AF and SSS in a large-scale prospective multicentre registry. METHODS: The Kansai Plus Atrial Fibrillation (KPAF) registry enrolled 5,010 consecutive patients who underwent CA for AF; this included 3,133 patients with paroxysmal AF (mean age, 66 years; male, 69.3%; mean CHA2DS2-VASc score, 2.05±1.50; SSS, n=315 [tachy-brady syndrome, n=285]). The endpoints included the recurrence of AF with a blanking period of 90 days after CA, and de novo pacemaker implantation during the follow-up period (median duration, 2.93 years). RESULTS: The AF-free survival did not significantly differ between patients with and those without SSS (n=2,818) after the initial (log-rank p=0.864) and final sessions (log-rank p=0.268). Pacemakers were implanted in 48 patients with SSS, and implantation in this group was significantly associated with AF recurrence, including early recurrence (adjusted odds ratio, 3.57; 95% confidence interval, 1.67-7.64; p=0.002). The remaining 85.3% of patients with SSS did not require pacemaker implantation at 3 years after CA. CONCLUSIONS: Coexisting SSS did not adversely affect recurrence-free survival after CA for paroxysmal AF. Pacemaker implantation was not required in most patients with SSS, with AF recurrence serving as a strong predictor for this.

Dynamic Changes in Electrocardiogram Parameters After Epicardial Substrate Catheter Ablation of Brugada Syndrome.

BACKGROUND: Catheter ablation (CA) is effective for recurrent episodes of ventricular fibrillation (VF) in Brugada syndrome (BrS). VF development in BrS is associated with several electrocardiogram (ECG) abnormalities. This study investigated changes in ECG parameters in high-risk BrS patients who underwent epicardial CA.Methods and Results:In all, 27 BrS patients were implanted with an implantable cardioverter-defibrillator (ICD). Patients were divided into 2 groups: (1) an ablation group (n=11) that underwent epicardial CA because of VF recurrence; and (2) a primary prevention (PP) group (n=16) with ICD implantation only. ECG parameters were evaluated before and 12 months after CA and compared with ECG parameters in the PP group. The T wave peak-to-end interval was significantly longer and the number of abnormal spikes in leads V1-V3 at the second, third, and fourth intercostal spaces was greater in the ablation than PP group. After ablation, ST levels and the sum of abnormal spikes in leads V1-V3 were significantly decreased. The mean (±SD) number of ICD shocks decreased markedly during a mean follow-up period of 42.0 months (from 3.8±3.7 to 0.2±0.4/year). Four patients had an ICD shock following the ablation procedure. Greater reductions in ST-segment elevation and abnormal spikes were observed in the group without than with VF recurrence. CONCLUSIONS: Improvements in surface ECG parameters appear to be associated with successful ablation in high-risk BrS patients.

The mechanism and prognosis of acute and late improvement in mitral regurgitation after cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) improves functional mitral regurgitation (MR); however, the mechanism and differences in acute and late improvement in MR are unclear. We aimed to evaluate the factors associated with the acute and late MR improvements and the prognosis of MR improvement after CRT. This retrospective study included 121 patients who underwent CRT implantation with full echocardiography assessment at baseline, 1 week, and 6 months after implantation. MR severity was classified into five grades (0: none to 4: severe). Two-dimensional speckle-tracking echocardiography with radial strain was used to assess dyssynchrony, and the time difference between the lateral and inferior segments at papillary muscle levels (TDlate-inf) was calculated. The MR improved 1 week and 6 months after CRT in 40 (33%) and 45 (37%) patients, respectively. On multivariate analyses, TDlate-inf (baseline-1 week) and SPWMD were independently associated with acute MR improvement. The %reduction in left ventricular end-systolic volume (LVESV) (baseline-6 months) and TDlate-inf (baseline-1 week) were independently correlated with late MR improvement. The patients with pre-MR grades 2-4 and improved MR after CRT showed significantly better prognosis in heart failure hospitalization. Cutoff values of ≥ 19.5 ms of the reduction of TDlate-inf and ≥ 30.8% of the %reduction of LVESV were significantly associated with the decrease in heart failure hospitalization. The improved interpapillary muscle activation time delay and volume reduction after CRT were associated with acute and late MR improvements. There may be different time course of recovery and distinct causes for late MR improvement.

Early improvement of daily physical activity after catheter ablation for atrial fibrillation in an accelerometer assessment: A prospective pilot study.

BACKGROUND: Catheter ablation improves physical activity in patients with atrial fibrillation (AF). However, continuous daily evaluation and time course of improvement in physical activity after ablation have not been fully assessed. This prospective study was conducted to evaluate the daily physical activities and changes in the physical performance in patients undergoing catheter ablation for AF by continuous monitoring of a portable accelerometer. METHODS: Ten patients scheduled for catheter ablation for AF were fitted with a uniaxial accelerometer prior to and 6 months after the procedure. This study evaluated changes in daily steps, activity intensity, and activity duration. We also evaluated changes in activity intensity using a short version of the International Physical Activity Questionnaire (IPAQ). RESULTS: The maximum daily steps significantly increased from baseline to postablation (baseline, 9,232 [6,716-11,485]; after 1-3 months, 11,605 [8,285-14,802]; and after 4-6 months, 11,412 [8,939-13,808], p = .020). Similarly, Δ maximum-mean daily steps increased significantly (baseline, 2,431 [1,199-6,181]; after 1-3 months, 4,674 [4,164-6,474]; and after 4-6 months, 4,871 [3,657-6,117], p = .014). These improvements were more pronounced in patients with paroxysmal and symptomatic AF. The total IPAQ score significantly improved from baseline to after 6 months ablation (from 1,170 [693-3,930] to 4,312 [1,865-6,569], p = .037). All patients were recurrence-free from AF after ablation. CONCLUSIONS: The physical activity improved significantly even in the early phase following catheter ablation. The effect of suppressing AF on activity levels was apparent soon after the procedure.

Electrocardiogram characteristics of P wave associated with successful pulmonary vein isolation in patients with paroxysmal atrial fibrillation: Significance of changes in P-wave duration and notched P wave.

BACKGROUND: The mechanisms involved in changes in P wave following catheter ablation for atrial fibrillation (AF) are uncertain. This study aimed to assess the relationship between changes in P-wave morphology and pulmonary vein (PV) reconnection following ablation by the assessment of 12-lead surface electrocardiogram and signal-averaged electrocardiogram. METHODS: This retrospective study included 115 consecutive patients with paroxysmal AF that underwent repeat ablation for recurrence following initial ablation. We investigated changes in P-wave morphology between baseline and repeat procedure in patients with and without PV reconnection. The study also included as validation group without recurrence (n = 67) following initial ablation. RESULTS: The maximum P-wave duration (PWD) was significantly decreased from baseline to just after the procedure in all groups. However, for the PV reconnection group (n = 100), the maximum PWD was significantly increased again at the repeat procedure. In contrast, the maximum PWD was significantly reduced between baseline and repeat procedure in the non-PV reconnection group (n = 15). The signal-averaged PWD was significantly decreased from baseline to repeat procedure in the non-PV reconnection group, but, conversely, was increased in the PV reconnection group. In the non-PV reconnection group, the disappearance of notched P wave was detected in 8 of 15 patients (53%), which was significantly higher than in other groups (p = .001). A new or delayed notched P wave was identified in the PV reconnection group only. These results were confirmed in the validation group. CONCLUSIONS: The reverse dynamics of PWD after initial shortening directly following ablation were significantly associated with PV reconnection.

T-wave changes of cardiac memory caused by frequent premature ventricular contractions originating from the right ventricular outflow tract.

INTRODUCTION: Cardiac memory is recognized as altered T-waves when the sinus rhythm resumes after an abnormal myocardial activation period that recovers slowly over several weeks. The T-wave changes after ablation of frequent premature ventricular contractions (PVCs) as cardiac memory was not known. OBJECTIVE: This study identified whether cardiac memory exists after successful ablation of PVCs from the right ventricular outflow tract (RVOT). METHODS: We investigated 45 patients who underwent successful ablation of PVCs from RVOT and 10 patients who underwent unsuccessful ablation. We analyzed the amplitude of the T-wave, QT intervals, and QRST time-integral values of a 12-lead electrocardiogram before ablation and 1 day, 3 days, and 1 month after ablation. RESULTS: In the successful ablation group, the amplitude of the T-wave and QRST time-integral values of lead II, III, aVR, aVL, and aVF significantly changed after ablation and gradually normalized within 1 month. In addition, if the number of pre-ablation PVCs was small, then the corresponding impact was also small. However, the greater the number of pre-ablation PVCs, the more prominent the changes. Significant changes were not observed in the unsuccessful ablation group. CONCLUSION: When ablation of PVCs from RVOT was successful, primary T-wave changes because of cardiac memory and the gradual normalization of the amplitude of the T-wave were observed. No significant T-wave changes were detected after unsuccessful ablation.

Discontinuous contraction in the left ventricle assessed by 2-D speckle tracking echocardiography benefits from CRT.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves the morbidity and mortality rate in patients with left bundle-branch block (LBBB); however, some LBBB patients are non-responders for CRT. Previous studies have shown that a transmural functional line block alters the left ventricular (LV) activation sequence, and that the presence of a line block is predictive for responders. We investigated whether responders could be predicted in patients with LBBB by 2-dimensional (2-D) speckle tracking strain imaging. METHODS: We enrolled 54 patients with LBBB, who underwent echocardiography before and 6 months after CRT implantation. A responder was defined by a decrease in the LV end-systolic volume >15% at the 6-month follow-up. We calculated a difference in the time from QRS onset to maximum strain between adjacent segments and defined the Tmax-diff as the maximum difference among six intersegments. We compared the Tmax-diff between responders and non-responders. RESULTS: Among 54 patients, 37 patients were identified as responders. The Tmax-diff of the responders was significantly longer than that of the non-responders (309.6 ± 168.6 ms vs 181.5 ± 138.4 ms, P = .009). Furthermore, Tmax-diff ≥ 195 ms was higher in the septal and the anterior area. And patients with a Tmax-diff ≥ 195 ms tended to be responders (P = .02). CONCLUSION: The present study showed that discontinuous contraction of the LV could be detected in CRT responders by 2-D speckle tracking strain imaging, which may be a useful tool to identify the contraction pattern of patients with LBBB and predict CRT responders.

Clinical significance of the timing of early recurrence of atrial arrhythmia after pulmonary vein isolation: a two-institution clinical study.

Early recurrence of atrial arrhythmia (ERAA) after ablation frequently occurs, but there is limited evidence about ERAA-timing. This study aimed to investigate the association between ERAA-timing and late recurrence. We retrospectively investigated 332 patients who underwent PVI for paroxysmal atrial fibrillation at Nagoya University Hospital and Komaki City Hospital. Seventy-six patients (23%) had ERAA. The cutoff value of the first ERAA for late recurrence was set as 3 days, with a specificity of 77% and sensitivity of 43%. On multivariate analysis, first ERAA beyond 3 days (hazard ratio, 2.477; 95% confidence interval, 1.168-5.25; p = 0.018) and large left atrial diameter (LAD) (hazard ratio, 1.101; 95% confidence interval, 1.024-1.184; p = 0.009) were independent predictors for late recurrence. Patients who had first ERAA within 3 days and no ERAA beyond 3 days showed a significantly higher recurrence-free rate than those who had first ERAA beyond 3 days and those who had ERAA both within 3 days and beyond 3 days (89% versus 39%, 44%; p < 0.001). Moreover, the patients with ERAA within 3 days and LAD ≤ 37.7 mm showed a significantly higher recurrence-free rate than those with ERAA beyond 3 days and LAD > 37.7 mm, and as compared with the other patients (100% versus 26% and 60%, respectively; p < 0.001). ERAA beyond 3 days after ablation was a predictor for late recurrence. Among patients with ERAA, those with ERAA within 3 days and smaller LAD showed favorable prognosis after ablation.

Impact of basal inferolateral scar burden determined by automatic analysis of 99mTc-MIBI myocardial perfusion SPECT on the long-term prognosis of cardiac resynchronization therapy.

AIMS: Left-ventricular (LV) scarring may be associated with a poor response to cardiac resynchronization therapy (CRT). The automatic analysis of myocardial perfusion single-photon emission computed tomography (MP-SPECT) may provide objective quantification of LV scarring. We investigated the impact of LV scarring determined by an automatic analysis of MP-SPECT on short-term LV volume response as well as long-term outcome. METHODS AND RESULTS: We studied consecutive 51 patients who were eligible to undergo 99mTc-MIBI MP-SPECT both at baseline and 6 months after CRT (ischaemic cardiomyopathies 31%). Quantitative perfusion SPECT was used to evaluate the defect extent (an index of global scarring) and the LV 17-segment regional uptake ratio (an inverse index of regional scar burden). The primary outcome was the composite of overall mortality or first hospitalization for worsening heart failure. A high global scar burden and a low mid/basal inferolateral regional uptake ratio were associated with volume non-responders to CRT at 6 months. The basal inferolateral regional uptake ratio remained as a predictor of volume non-response after adjusting for the type of cardiomyopathy. During a median follow-up of 36.1 months, the outcome occurred in 28 patients. The patients with a low basal inferolateral regional uptake ratio with a cutoff value of 57% showed poor prognosis (log-rank P= 0.006). CONCLUSION: The scarring determined by automatic analysis of MP-SPECT images may predict a poor response to CRT regardless of the pathogenesis of cardiomyopathy. The basal inferolateral scar burden in particular may have an adverse impact on long-term prognosis.

Distributions and number of drivers on real-time phase mapping associated with successful atrial fibrillation termination during catheter ablation for non-paroxysmal atrial fibrillation.

BACKGROUND: Real-time phase mapping (ExTRa™) is useful in determining the strategy of catheter ablation for non-paroxysmal atrial fibrillation (AF). This study aimed to investigate the features of drivers of AF associated with its termination during ablation. METHODS: Thirty-six patients who underwent catheter ablation for non-paroxysmal AF using online real-time phase mapping (ExTRa™) were enrolled. A significant AF driver was defined as an area with a non-passively activated ratio of ≥ 50% on mapping analysis in the left atrium (LA). All drivers were simultaneously evaluated using a low-voltage area, complex fractionated atrial electrogram (CFAE), and rotational activity by unipolar electrogram analysis. The electrical characteristics of drivers were compared between patients with and without AF termination during the procedure. RESULTS: Twelve patients achieved AF termination during the procedure. The total number of drivers detected on the mapping was significantly lower (4.4 ± 1.6 vs. 7.4 ± 3.8, p = 0.007), and the drivers were more concentrated in limited LA regions (2.8 ± 0.9 vs. 3.9 ± 1.4, p = 0.009) in the termination group than in the non-termination group. The presence of drivers 2-6 with limited (≤ 3) LA regions showed a tenfold increase in the likelihood of AF termination, with 83% specificity and 67% sensitivity. Among 231 AF drivers, the drivers related to termination exhibited a greater overlap of CFAE (56.8 ± 34.1% vs. 39.5 ± 30.4%, p = 0.004) than the non-related drivers. The termination group showed a trend toward a lower recurrence rate after ablation (p = 0.163). CONCLUSIONS: Rotors responsible for AF maintenance may be characterized in cases with concentrated regions and fewer drivers on mapping.

Periprocedural Management of Cardiac Tamponade During Catheter Ablation for AF Under Uninterrupted DOAC and Warfarin.

OBJECTIVES: This was a retrospective analysis of a registry of patients who underwent catheter ablation for atrial fibrillation (AF) under uninterrupted direct oral anticoagulant (DOAC) and warfarin administration. BACKGROUND: Uninterrupted DOAC used during catheter ablation for AF causes a life-threatening bleeding risk of cardiac tamponade. METHODS: Of 3,149 catheter ablation procedures for AF with uninterrupted oral anticoagulants used in 2,406 patients in 3 institutions, DOAC and warfarin were administered in 1,896 and 1,253 procedures, respectively. Among them, cardiac tamponade requiring pericardiocentesis and surgical intervention occurred in 13 (0.7%) and 11 (0.9%) procedures in the DOAC and warfarin groups, respectively. In this study, the outcomes between these 2 groups were compared. RESULTS: The total blood volumes drained after pericardiocentesis was 300 (190 to 715) ml and 300 (200 to 380) ml in the DOAC and warfarin groups, respectively (p = 0.697). Approximately two-thirds of patients (9 in the DOAC group and 7 in the warfarin group) recovered with only pericardiocentesis and protamine infusion (including vitamin K in the warfarin group) in both groups. Two patients in the DOAC group underwent surgical intervention but recovered uneventfully, whereas none of the patients taking warfarin required surgical intervention. DOAC and warfarin were successfully resumed 2.0 (2.0 to 5.0) days and 4.0 (2.0 to 5.5) days after tamponade in all patients without an increase in effusion (p = 0.102). CONCLUSIONS: Managing cardiac tamponade under uninterrupted DOAC administration was feasible. Early intensive treatment resulted in hemostasis in most patients. However, surgical intervention was required in some cases refractory to the initial treatment.

Prothrombotic Responses After Catheter Ablation for Atrial Fibrillation During Uninterrupted Oral Anticoagulant Agent Administration.

OBJECTIVES: The aim of this study was to evaluate the extent of changes in prothrombotic responses after catheter ablation for atrial fibrillation (AF) under uninterrupted oral anticoagulant agent (OAC) administration. BACKGROUND: Catheter ablation for AF has a potential risk for prothrombotic activation and silent thromboembolic events. METHODS: A total of 814 patients (n = 172 [warfarin], n = 153 [dabigatran], n = 134 [rivaroxaban], and n = 301 [apixaban] patients undergoing AF ablation and a control group of 54 patients undergoing non-AF ablation) were included. Uninterrupted OACs were administered during the procedure in patients with AF. Blood samples were collected the day before and 3 days after the procedure. RESULTS: At baseline, D-dimer levels were within normal limits (≤1.0 µg/ml) in more than 90% of the patients in all groups. However, after 3 days, this proportion decreased to 67%, 73%, 59%, 68%, and 65% in the warfarin, dabigatran, rivaroxaban, apixaban, and control groups, respectively (p = 0.180). Changes in prothrombin fragment 1+2 levels differed (p < 0.001), whereas fibrin monomer complex levels 3 days after ablation at a trough were equivalent within normal ranges among the groups (p = 0.146). Multivariate analysis revealed that age, CHA2DS2-VASc score, first session, and radiofrequency ablation were independent predictors of increased D-dimer levels after the procedure. Various changes in prothrombotic markers were observed between the warfarin and direct OAC groups after propensity score matching analyses. CONCLUSIONS: The coagulation cascade was activated after catheter ablation for AF under uninterrupted OAC administration. The changes in various prothrombotic markers differed among the OAC groups.

Non-vitamin K antagonist oral anticoagulants versus warfarin for cardioversion of atrial fibrillation in clinical practice: A single-center experience.

BACKGROUND: Anticoagulation therapy with the vitamin K antagonist (VKA) warfarin has been demonstrated to reduce thromboembolic risk after electrical cardioversion (ECV). However, data concerning ECV with non-VKA oral anticoagulants (NOACs) is limited. The objective of this study was to determine the efficacy and safety of NOACs in patients undergoing ECV in a real-world clinical practice at a single center in Japan. METHODS: We retrospectively analyzed the data of 406 consecutive patients who underwent ECV for atrial fibrillation (AF) or flutter under anticoagulation with one of the three NOACs (n=149) or with a VKA (n=257). RESULTS: The CHADS2 and HAS-BLED scores were significantly higher in the VKA group, whereas the NOACs group had a tendency toward greater spontaneous echo contrast grades. After ECV, ischemic stroke occurred in three patients of the VKA group and one patient in the NOAC group, all of whom had persistent AF, indicating no significant difference in the thromboembolic event rate within 30 days following ECV. No other thromboembolic events, major bleeding, or death occurred in either group. Among the NOAC and VKA patients in whom we newly introduced an oral anticoagulant to perform ECV, the number of days leading to ECV was significantly lesser for the NOAC patients. CONCLUSION: NOACs may be used as an alternative to VKAs for ECV and may allow prompt ECV in clinical practices.

Comparison of Frequency and Characteristics of Patients With Atrial Fibrillation Having Ablation With Versus Without Coronary Narrowing (≥50%) by Angiography.

Atrial fibrillation (AF) shares background comorbidities with coronary artery disease (CAD), including hypertension and diabetes mellitus. The aim of the study is to evaluate the prevalence, risk factors, and prognostic significance of CAD among patients who underwent catheter ablation for AF. In 544 consecutive registered patients who underwent catheter ablation for AF (CHADS2 score 1.2 ± 1.1, paroxysmal AF 57%), quantitative coronary angiography was used to detect CAD, defined as luminal narrowing of ≥50% in diameter. Univariate and multiple logistic regression analyses were applied to evaluate the risk factors of CAD. Subsequent clinical events up to 1 year were obtained in all the patients. CAD was found in 70 patients (13%). The factors associated with the presence of CAD in AF patients who underwent catheter ablation were similar to traditional coronary risk factors such as hypertension and diabetes mellitus. AF patients with CAD had a higher CHADS2 score than those without CAD (1.5 ± 1.1 vs 1.1 ± 1.0, p = 0.009). Hence, a CHADS2 score ≥1 may be an alternative risk factor to predict CAD. Previous coronary revascularization (14% with CAD vs 6% without CAD) and paroxysmal AF (69% vs 55%) were also associated with CAD. During follow-up, patients with CAD experienced acute coronary syndrome (n = 2) and coronary revascularization (n = 18); no such events were recorded in those without CAD. In addition to traditional risk factors, CHADS2 score, previous revascularization, and paroxysmal AF may be new risk factors for CAD in AF patients.