Abstract Background The underlying mechanisms sustaining human persistent atrial fibrillation (PsAF) is poorly understood. Objectives This study sought to investigate the complexity and distribution ...of AF drivers in PsAF of varying durations. Methods Of 135 consecutive patients with PsAF, 105 patients referred for de novo ablation of PsAF were prospectively recruited. Patients were divided into 3 groups according to AF duration: PsAF presenting in sinus rhythm (AF induced), PsAF <12 months, and PsAF >12 months. Patients wore a 252-electrode vest for body surface mapping. Localized drivers (re-entrant or focal) were identified using phase-mapping algorithms. Results In this patient cohort, the most prominent re-entrant driver regions included the pulmonary vein (PV) regions and inferoposterior left atrial wall. Focal drivers were observed in 1 or both PV regions in 75% of patients. Comparing between the 3 groups, with longer AF duration AF complexity increased, reflected by increased number of re-entrant rotations (p < 0.05), number of re-entrant rotations and focal events (p < 0.05), and number of regions harboring re-entrant (p < 0.01) and focal (p < 0.05) drivers. With increased AF duration, a higher proportion of patients had multiple extra-PV driver regions, specifically in the inferoposterior left atrium (p < 0.01), superior right atrium (p < 0.05), and inferior right atrium (p < 0.05). Procedural AF termination was achieved in 70% of patients, but decreased with longer AF duration. Conclusions The complexity of AF drivers increases with prolonged AF duration. Re-entrant and focal drivers are predominantly located in the PV antral and adjacent regions. However, with longer AF duration, multiple drivers are distributed at extra-PV sites. AF termination rate declines as patients progress to longstanding PsAF, underscoring the importance of early intervention.
Specific noninvasive signal processing was applied to identify drivers in distinct categories of persistent atrial fibrillation (AF).
In 103 consecutive patients with persistent AF, accurate biatrial ...geometry relative to an array of 252 body surface electrodes was obtained from a noncontrast computed tomography scan. The reconstructed unipolar AF electrograms acquired at bedside from multiple windows (duration, 9±1 s) were signal processed to identify the drivers (focal or reentrant activity) and their cumulative density map. The driver domains were catheter ablated by using AF termination as the procedural end point in comparison with the stepwise-ablation control group. The maps showed incessantly changing beat-to-beat wave fronts and varying spatiotemporal behavior of driver activities. Reentries were not sustained (median, 2.6 rotations lasting 449±89 ms), meandered substantially but recurred repetitively in the same region. In total, 4720 drivers were identified in 103 patients: 3802 (80.5%) reentries and 918 (19.5%) focal breakthroughs; most of them colocalized. Of these, 69% reentries and 71% foci were in the left atrium. Driver ablation alone terminated 75% and 15% of persistent and long-lasting AF, respectively. The number of targeted driver regions increased with the duration of continuous AF: 2 in patients presenting in sinus rhythm, 3 in AF lasting 1 to 3 months, 4 in AF lasting 4 to 6 months, and 6 in AF lasting longer. The termination rate sharply declined after 6 months. The mean radiofrequency delivery to AF termination was 28±17 minutes versus 65±33 minutes in the control group (P<0.0001). At 12 months, 85% patients with AF termination were free from AF, similar to the control population (87%,); P=not significant.
Persistent AF in early months is maintained predominantly by drivers clustered in a few regions, most of them being unstable reentries.
Atrial fibrillation (AF) is the most common arrhythmia and often recurs despite catheter ablation. The recurrence of AF is often underdiagnosed by standard 24-hour electrocardiogram (ECG) because of ...its transient and silent nature. A garment-style ECG with a highly conductive textile electrode made of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)(PEDOTPSS) and nanofiber (Garment ECG) has been developed that can provide longer-term continuous monitoring. This study investigated whether 2-week Garment ECG can reveal instances of AF recurrence in patients who are diagnosed as remaining in sinus rhythm by 24-hour Holter ECG.
The open-label randomized crossover study enrolled 67 patients (63.1±10.6 years old, 53 men) who had undergone initial AF ablation. Three months after ablation, patients were randomly assigned to group 1 (n = 35), 2-week Garment ECG followed by 24-hour Holter ECG, or group 2 (n = 32), 24-hour Holter ECG followed by 2-week Garment ECG. The detection of AF recurrence was compared between the two devices.
The Garment ECG showed AF recurrence in 12 patients (18%) compared to 4 patients for the Holter ECG (6%, p = 0.008). The ECG acquisition rate was higher for Holter ECG than for Garment ECG (100.0% interquartile range 100.0-100.0% versus 82.4% 71.1-91.0%, p<0.001), but the Garment ECG provided longer total analysis time (11.0 days 9.0-12.2 days for Garment; 1.0 day 1.0-1.0 day for Holter, p<0.001).
Despite the lower ECG acquisition rate, the 2-week Garment ECG revealed instances of AF recurrence after ablation in patients who were underdiagnosed by 24-hour Holter ECG.
Clinical Trial Registration: URL: https://jrct.niph.go.jp/en-latest-detail/jRCTs032180018 Unique Identifier: jRCTs032180018.
This study aimed to determine 5-year efficacy of catheter ablation for persistent atrial fibrillation (AF) using AF termination as a procedural end point.
One hundred fifty patients (57±10 years) ...underwent persistent AF ablation using a stepwise ablation approach (pulmonary vein isolation, electrogram-guided, and linear ablation) with the desired procedural end point being AF termination. Repeat ablation was performed for recurrent AF or atrial tachycardia. AF was terminated by ablation in 120 patients (80%). Arrhythmia-free survival rates after a single procedure were 35.3%±3.9%, 28.0%±3.7%, and 16.8%±3.2% at 1, 2, and 5 years, respectively. Arrhythmia-free survival rates after the last procedure (mean 2.1±1.0 procedures) were 89.7%±2.5%, 79.8%±3.4%, and 62.9%±4.5%, at 1, 2, and 5 years, respectively. During a median follow-up of 58 (interquartile range, 43-73) months after the last ablation procedure, 97 of 150 (64.7%) patients remained in sinus rhythm without antiarrhythmic drugs. Another 14 (9.3%) patients maintained sinus rhythm after reinitiation of antiarrhythmic drugs, and an additional 15 (10.0%) patients regressed to paroxysmal recurrences only. Failure to terminate AF during the index procedure (hazard ratio 3.831; 95% confidence interval, 2.070-7.143; P<0.001), left atrial diameter≥50 mm (hazard ratio 2.083; 95% confidence interval, 1.078-4.016; P=0.03), continuous AF duration≥18 months (hazard ratio 1.984; 95% confidence interval, 1.024-3.846; P<0.04), and structural heart disease (hazard ratio 1.874; 95% confidence interval, 1.037-3.388; P=0.04) predicted arrhythmia recurrence.
In patients with persistent AF, an ablation strategy aiming at AF termination is associated with freedom from arrhythmia recurrence in the majority of patients over a 5-year follow-up period. Procedural AF nontermination and specific baseline factors predict long-term outcome after ablation.
Successful bipolar radiofrequency catheter ablation (RFCA) of refractory ventricular arrhythmias (VAs) has been reported. However, the efficacy, safety, and long-term outcomes of bipolar RFCA of VAs ...are not fully determined.
The purpose of this study was to evaluate the effectiveness and safety of bipolar RFCA in treating refractory VAs during long-term follow-up.
Eighteen patients who underwent bipolar RFCA for ventricular tachycardia (VT) at 7 institutions were retrospectively investigated. Underlying heart diseases included remote myocardial infarction (n = 3 17%) and nonischemic cardiomyopathy (n = 15 83%). Although unipolar RFCA was performed in all patients, either it failed to suppress VT or VT recurred. The interventricular septum, left ventricular free wall, and left ventricular summit were targeted for bipolar RFCA.
Acute success (VT termination and/or noninducibility) was achieved with bipolar RFCA in 16 patients (89%). Complications during the procedure included complete atrioventricular block (n = 2) and coronary artery stenosis (n = 1). One patient underwent chemical ablation after bipolar RFCA failure. At 12-month follow-up, VT reoccurred in 8 patients (44%). However, in patients with recurrence, VT burden had decreased: only 4 patients underwent re-RFCA, and only 1 of the 4 required chemical ablation. In the remaining 4 patients, re-RFCA was not required, as VT was controlled by medication or an implantable cardioverter–defibrillator.
Bipolar RFCA is useful for acute suppression of refractory VT. Although VT recurrence rates during long-term follow-up were relatively high, we observed a significant reduction in VT burden.
Introduction
There are few studies analyzing the association between the presence of coronary artery disease (CAD) and recurrence of atrial fibrillation (AF). This study evaluated the clinical impact ...of concomitant CAD and coronary revascularization on the recurrence of AF after catheter ablation.
Methods and Results
From April 2008 to December 2015, 700 consecutive patients were treated with pulmonary vein isolation for AF as the initial procedure. Of those, 681 patients who simultaneously underwent coronary angiography were investigated. Patients with at least one coronary stenosis (≥70%) were classified as having obstructive CAD. Of 681 patients, 90 patients had CAD and 42 patients underwent percutaneous coronary intervention (PCI) for lesions with perfusion abnormalities on single‐photon emission tomography. The recurrence of AF was significantly more frequent in patients with CAD (56%) than in those without CAD (39%) (P = .0011). On multivariable analysis, the predictors of AF recurrence were persistent or long‐standing persistent AF hazard ratio (HR): 1.36; 95% confidence interval (CI): 1.04‐1.77; P = .023, left atrial diameter (HR: 1.04; 95% CI: 1.02‐1.06; P < .0001), and concomitant CAD (HR: 1.45; 95% CI: 1.05‐1.97; P = .024). The recurrence of AF in patients with PCI (38%) was significantly lower than in those without PCI (72%) (P = .0006), and E/E′ significantly improved in patients with PCI (71%) than in those without PCI (42%; P = .001). Performing PCI for concomitant CAD significantly reduced AF recurrence (HR: 0.39; 95% CI: 0.20‐0.72; P = .002).
Conclusion
Patients with CAD had a significantly higher rate of AF recurrence than those without CAD. Coronary revascularization may reduce the recurrence of AF with improvement of left ventricular diastolic function.
The therapeutic strategy for sustained ventricular tachycardia (VT) during left ventricular assist device usage remains unclear. We encountered a patient with durable left ventricular assist device ...who presented sustained VT. Electrophysiological mapping was able to be established appropriately owing to the robust mechanical hemodynamics support despite inter-device interference. The three-dimensional activation map of clinically documented VT demonstrated that the propagation exited from the right ventricular apex through the critical isthmus located at the epicardium or interventricular septum, which was successfully treated by catheter ablation at the exit site. Further experiences like ours should be accumulated to establish a therapeutic strategy.
Introduction
Catheter ablation is a therapeutic option to suppress ventricular tachycardia (VT) in the setting of dilated‐phase hypertrophic cardiomyopathy (DHCM). However, the characteristics of the ...arrhythmogenic substrate and the ablation outcome are not fully illustrated.
Method
A total of 23 ablation procedures for drug‐refractory sustained monomorphic VTs in 13 DHCM patients (60 ± 11 years, one female, the left ventricular LV ejection fraction 39% ± 9%, the LV mass index 156 ± 39 g/m2) were performed. The distribution of VT substrate as endocardial or epicardial/intramural was based on detailed mapping and ablation response during VT.
Result
Two patients underwent ablation of sustained monomorphic VT that was not scar‐mediated tachycardia. Of the remaining 11 patients, eight (73%) patients had VT substrate in the basal regions, most frequently at the epicardial and/or intramural basal antero‐septum. None of the patients had VT substrate located at the LV inferolateral region. Ablation at the right ventricular septum and the aortic cusps was done in four and five patients, respectively. Other approaches including bipolar and chemical ablations, were done in three and two patients, respectively. Six (55%) out of 11 patients (two patients lost follow‐up) had VT recurrence. All the six patients had basal substrate. However, anti‐tachycardia pacing was sufficient for VT termination except in one patient.
Conclusion
Catheter ablation of VT in patients with DHCM is challenging because of the predominant basal anteroseptal epicardial/intramural location of arrhythmogenic substrate. An ablation approach from multiple sites and/or adjunctive interventional techniques are often required.
Purpose
Antral pulmonary vein isolation (PVI) using a radiofrequency hot balloon catheter (RHB) is a feasible therapeutic option for treating atrial fibrillation (AF). Lesion durability after antral ...RHB-PVI remains unknown. This study aimed to evaluate lesion durability and the associations between procedural characteristics after antral RHB-PVI.
Methods
A total of 200 patients received antral RHB-PVI using the single-shot technique between April 2016 and March 2018. Antral RHB-PVI was performed following a pre-specified protocol and RHB energy application was performed for a maximum of two times for each PV. Consecutive patients who underwent repeated procedures for recurrence of any type of atrial tachyarrhythmia were enrolled.
Results
Twenty-six (13%) patients underwent repeated ablation and 20 patient documented AF recurrence (AF group) and 6 patients documented non-AF recurrence (non-AF group). Repeated ablation was performed at a median (25th, 75th percentiles) of 378 days (217, 487) after the initial procedure and durable PVI was observed in 86 (83.5%) PVs. Durability reached 89.7% when PVI was achieved only using an RHB. In the AF group (79 PVs), durable PVI was observed in 62 (78.5%) PVs, whereas all 24 PVs were still isolated in the non-AF group. The majority of reconnection sites were around the superior PVs.
Conclusions
Antral RHB-PVI shows high lesion durability, especially with both inferior PVs.
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