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.
Non-invasive electrocardiogram (ECG) mapping allows the activation of the entire atrial epicardium to be recorded simultaneously, potentially identifying mechanisms critical for atrial fibrillation ...(AF) persistence. We sought to evaluate the utility of ECG mapping as a practical tool prior to ablation of persistent AF (PsAF) in centres with no practical experience of the system.
A total of 118 patients with continuous AF duration <1 year were prospectively studied at 8 European centres. Patients were on a median of 1 antiarrhythmic drug (AAD) that had failed to restore sinus rhythm. Electrocardiogram mapping (ECVUE™, CardioInsight, USA) was performed prior to ablation to map AF drivers (local re-entrant circuits or focal breakthroughs). Ablation targeted drivers depicted by the system, followed by pulmonary vein (PV) isolation, and finally left atrial linear ablation if AF persisted. The primary endpoint was AF termination. Totally, 4.9 ± 1.0 driver sites were mapped per patient with a cumulative mapping time of 16 ± 2 s. Of these, 53% of drivers were located in the left atrium, 27% in the right atrium, and 20% in the anterior interatrial groove. Driver-only ablation resulted in AF termination in 75 of the 118 patients (64%) with a mean radiofrequency (RF) duration of 46 ± 28 min. Acute termination rates were not significantly different amongst all 8 centres (P = 0.672). Ten additional patients terminated with PV isolation and lines resulting in a total AF termination rate of 72%. Total RF duration was 75 ± 27 min. At 1-year follow-up, 78% of the patients were off AADs and 77% of the patients were free from AF recurrence. Of the patients with no AF recurrence, 49% experienced at least one episode of atrial tachycardia (AT) which required either continued AAD therapy, cardioversion, or repeat ablation.
Non-invasive mapping identifies biatrial drivers that are critical in PsAF. This is validated by successful AF termination in the majority of patients treated in centres with no experience of the system. Ablation targeting these drivers results in favourable AF-free survival at 1 year, albeit with a significant rate of AT recurrence requiring further management.
The report from the 2nd Consensus Committee on BrS suggests that all patients with syncope without a "clear extracardiac cause" should have an implantable cardioverter-defibrillator (ICD). However, a ...clear extracardiac cause for syncope may be difficult to prove.
The purpose of this study was to characterize syncope in patients with Brugada syndrome (BrS).
All patients diagnosed with BrS at our institution between 1999 and 2010 were enrolled in a prospective registry. Patients with suspected arrhythmic syncope (group 1) were compared to patients with nonarrhythmic syncope (group 2) and to patients with syncope of doubtful origin (group 3).
Of 203 patients with BrS, 57 (28%; 44 male, age 46 ± 12 years) experienced at least 1 syncope. Group 1 consisted of 23 patients, all of whom received an ICD. In group 2 (17 patients), 3 received an ICD because of a positive electrophysiologic study. In group 3 (17 patients), 6 received an implantable loop recorder and 6 received an ICD. After mean follow-up of 65 ± 42 months, 14 patients in group 1 remained asymptomatic, 4 had recurrent syncope, and 6 had appropriate ICD therapy. In group 2, 9 patients remained asymptomatic and 7 had recurrent neurocardiogenic syncope. In group 3, 7 remained asymptomatic and 9 had recurrent syncope. One patient from each group died from a noncardiac cause.
In the present study, syncope occurred in 28% of patients with BrS. The ventricular arrhythmia rate was 5.5% per year in group 1. In 30%, the etiology of the syncope was questionable. No sudden cardiac death occurred in groups 2 and 3.
Local abnormal ventricular activities (LAVA) in patients with scar-related ventricular tachycardia (VT) may appear at any time during or after the far-field electrogram. Although they may be ...separated from the far-field signal by an isoelectric line and extend beyond the end of surface QRS, they may also appear fused or buried within the QRS.
The purpose of this study was to characterize LAVA in postinfarction VT patients with respect to their anatomic locations.
Thirty-one patients with postinfarction VT underwent mapping/ablation during sinus rhythm with a three-dimensional electroanatomic mapping system. From a total of 18,270 electrograms reviewed in all study subjects, 1104 LAVA (endocardium 839, epicardium 265) were identified and analyzed.
The interval from onset of QRS complex to ventricular electrogram (EGM onset) on the endocardium was significantly shorter than the epicardium (P < .001). EGM onset was shortest in the septal endocardium and longest in the inferior and lateral epicardium. There was a significant positive correlation between EGM onset and LAVA lateness as estimated by the interval from surface QRS onset to LAVA (r = 0.52, P < .001). LAVA were more frequently detected after the QRS complex in the epicardium (241/265 91%) than in the endocardium (551/839 66%, P < .001). Only 43% of endocardial septal LAVA were detected after the QRS complex.
Lateness of LAVA is affected to a large extent by their locations. The chance of detecting late LAVA increases when electrogram onset is later. Substrate-based approach targeting delayed signals relative to the QRS complex may miss critical the arrhythmogenic substrate, particularly in the septum and other early-to-activate regions.
Inferolateral early repolarization (ER) and Brugada syndrome manifest with J waves. Isoproterenol suppresses recurrent ventricular arrhythmias while reducing J waves in both disorders.
To ...characterize the effect of isoproterenol on J waves.
We analyzed the impact of isoproterenol on J waves in 20 patients with Brugada-type electrocardiogram (Br group) and 38 patients with ER (ER group).
In the ER group, J waves were present in inferior leads in 32 patients (84%) and in lateral leads in 23 patients (61%). Isoproterenol increased the heart rate by 75 beats/min in the ER group and by 71 beats/min in the Br group (P = .20). The incidences of persistent (≤ 0.05-mV decrease), decreased, and normalized J waves (residual J wave ≤ 0.05 mV) were 20%, 80%, and 0% for Br group patients and 29%, 8%, and 63% for ER group patients, respectively (P <.001). Within the ER group, inferior J waves persisted in 34% of the cases, decreased in 9%, and normalized in 56% whereas lateral J waves always normalized (P <.001). Baseline QRS width was broader in ER group patients with persistent J waves (90 ms vs 80 ms; P = .003) and was unchanged with isoproterenol (90 ms; P = .19), whereas it decreased in the remaining patients (75 ms; P <.001).
J-wave syndromes have distinct regional sensitivity to beta-adrenergic stimulation. J waves may persist in a subset of patients with right precordial and inferior J waves but never in lateral location. This heterogeneous response to isoproterenol may indicate distinctive mechanisms for Brugada and ER patterns, including depolarization abnormalities or ion channel sensitivity.
Atrial tachycardias (AT) during or after ablation of atrial fibrillation frequently pose a diagnostic challenge. We hypothesized that both the patterns and the timing of coronary sinus (CS) ...activation could facilitate AT mapping.
A total of 140 consecutive postpersistent atrial fibrillation ablation patients with sustained AT were investigated by conventional mapping. CS activation pattern was defined as chevron or reverse chevron when the activations recorded on both the proximal and the distal CS dipoles were latest or earliest, respectively. The local activation of mid-CS was timed with reference to Ppeak-Ppeak (P-P) interval in lead V1. A ratio, mid-CS activation time to AT cycle length, was computed. Of 223 diagnosed ATs, 124 were macroreentrant (56%) and 99 were centrifugal (44%). When CS activation was chevron/reverse chevron (n=44; 20%), macroreentries were mostly roof dependent. With reference to P-P interval, mid-CS activation timing showed specific consistency for peritricuspid and perimitral AT. Proximal to distal CS activation pattern and mid-CS activation at 50% to 70% of the P-P interval (n=30; 13%) diagnosed peritricuspid AT with 81% sensitivity and 89% specificity. Distal to proximal CS activation and mid-CS activation at 10% to 40% of the P-P interval (n=44; 20%) diagnosed perimitral AT with 88% sensitivity and 75% specificity.
The analysis of the patterns and timing of CS activation provides a rapid stratification of most likely macroreentrant ATs and points toward the likely origin of centrifugal ATs. It can be included in a stepwise diagnostic approach to rapidly select the most critical mapping maneuvers.
The efficacy of biventricular (BiV) pacing in patients with a narrow or moderately prolonged QRS duration remains questionable.
To assess the hypothesis that electrical dyssynchrony is required to ...obtain hemodynamic benefit from BiV pacing by investigating the relationship between intrinsic QRS duration and hemodynamic response to BiV pacing in a patient population covering a broad spectrum of QRS duration.
Eighty-two consecutive heart failure patients underwent cardiac resynchronization therapy implantation irrespective of their QRS duration. Thirty-four patients had a narrow QRS duration (<120 ms), whereas 11 patients had a moderately prolonged QRS duration (≥120 to <150 ms) and 37 patients had a severely prolonged QRS duration (≥150 ms). After implantation, invasive left ventricular (LV) dP/dt measurements were compared between intrinsic rhythm and simultaneous BiV pacing with an optimized atrioventricular delay.
A high correlation (r = .65; P < .001) was observed between baseline QRS duration and changes in LV dP/dt(max) induced by BiV pacing. BiV pacing was ineffective in patients with a narrow QRS duration (+0.4% ± 6.1%; P = ns). No significant increase in LV dP/dt(max) was observed in patients with a QRS duration of ≥120 to <150 ms (+4.4% ± 6.9%; P = .06), whereas patients with a QRS duration of ≥150 ms exhibited a significant increase in LV dP/dt(max) (+17.1% ± 13.4%; P <.001). Only 9% of the patients with a narrow QRS duration exhibited a ≥10% increase in LV dP/dt(max).
Baseline QRS duration is linearly related to acute hemodynamic response to BiV pacing. Patients with a narrow QRS duration do not derive hemodynamic improvement. This improvement is also limited in patients with a moderately prolonged QRS duration, raising questions about the potential clinical benefit of this therapy in these patients.
Atrial fibrillation (AF) ablation has evolved to the treatment of choice for patients with drug-resistant and
symptomatic AF. Pulmonary vein isolation at the ostial or antral level usually is ...sufficient for treatment of true paroxysmal
AF. For persistent AF ablation, drivers and perpetuators outside of the pulmonary veins are responsible for AF maintenance
and have to be targeted to achieve satisfying arrhythmia-free success rate. Both complex fractionated atrial electrogram
(CFAE) ablation and linear ablation are added to pulmonary vein isolation for persistent AF ablation. Nevertheless,
ablation failure and necessity of repeat ablations are still frequent, especially after persistent AF ablation. Pulmonary
vein reconduction is the main reason for arrhythmia recurrence after paroxysmal and to a lesser extent after persistent AF
ablation. Failure of persistent AF ablation mostly is a consequence of inadequate trigger ablation, substrate modification
or incompletely ablated or reconducting linear lesions. In this review we will discuss these points responsible for AF recurrence
after ablation and review current possibilities on how to overcome these limitations.
Contact force (CF) is an important determinant of lesion formation for atrial endocardial radiofrequency ablation. There are minimal published data on CF and ventricular lesion formation. We studied ...the impact of CF on lesion formation using an ovine model both endocardially and epicardially.
Twenty sheep received 160 epicardial and 160 endocardial ventricular radiofrequency applications using either a 3.5-mm irrigated-tip catheter (Thermocool, Biosense-Webster, n=160) or a 3.5 irrigated-tip catheter with CF assessment (Tacticath, Endosense, n=160), via percutaneous access. Power was delivered at 30 watts for 60 seconds, when either catheter/tissue contact was felt to be good or when CF>10 g with Tacticath. After completion of all lesions, acute dimensions were taken at pathology. Identifiable lesion formation from radiofrequency application was improved with the aid of CF information, from 78% to 98% on the endocardium (P<0.001) and from 90% to 100% on the epicardium (P=0.02). The mean total force was greater on the endocardium (39±18 g versus 21±14 g for the epicardium; P<0.001) mainly because of axial force. Despite the force-time integral being greater endocardially, epicardial lesions were larger (231±182 mm(3) versus 209±131 mm(3); P=0.02) probably because of the absence of the heat sink effect of the circulating blood and covered a greater area (41±27 mm(2) versus 29±17 mm(2); P=0.03) because of catheter orientation.
In the absence of CF feedback, 22% of endocardial radiofrequency applications that are thought to have good contact did not result in lesion formation. Epicardial ablation is associated with larger lesions.
The precise localization of manifest posteroseptal accessory pathways (APs) often poses diagnostic challenges considering that a small area may encompass AP that may be ablated from the right or left ...endocardium, or epicardially within the coronary sinus (CS). We sought to explore whether the QRS transition pattern in the precordial lead may help to discriminate the necessary ablation approach.
Consecutive patients who underwent a successful ablation of a single manifest AP over a 5-year period were included. Standard 12-lead electrocardiograms were reviewed. A total of 273 patients were identified. Mean age was 31 ± 15 years and 62% were male. Of the 110 identified posteroseptal AP, 64 were ablated from the right endocardium, 33 from the left endocardium, and 13 inside the CS. While a normal precordial QRS transition was most often observed, a subset of 33 patients presented an atypical 'double transition' pattern which specifically identified right endocardial AP. The combination of a q wave in V1 with a proportion of the positive QRS component in V1 < V2 > V3, predicted a right endocardial AP with a 100% specificity. In case of a positive QRS sum in V2, this 'double transition' pattern predicted a posteroseptal right endocardial AP with 99.5% specificity and 44% sensitivity. The positive predictive value was 97%. The only false positive was a midseptal AP. In the case of a negative or isoelectric QRS sum in V2, APs were located more laterally on the tricuspid annulus.
The combination of a q wave in V1 with a double QRS transition pattern in the precordial leads is highly specific of a right endocardial AP and rules out the need for CS or left-sided mapping.
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