This study sought to evaluate the safety and the acute and 1 year outcomes of an ablation protocol aiming to enclose the PV with a contiguous and optimized RF circle by targeting region-specific ...criteria for lesion depth assessed by ablation index and interlesion distance.
Reconnections after pulmonary vein (PV) isolation are explained by insufficient lesion depth and/or discontiguity of radiofrequency (RF) lesions.
A total of 130 consecutive patients with paroxysmal atrial fibrillation (AF) underwent PV encircling using a contact force-sensing catheter. RF was delivered targeting interlesion distance ≤6 mm and ablation index ≥400 at posterior wall and ≥550 at anterior wall. Recurrence was defined as any AF, atrial tachycardia (AT), or atrial flutter (AFL) (AF/AT/AFL >30 s) on Holter electrocardiographs at 3, 6, and 12 months.
Procedure and RF time per circle were 155 ± 28 min and 17 ± 5 min, respectively. Incidence of first-pass and adenosine-proof isolation were 98% and 98%, respectively. One short-lived transient ischemic attack was observed. At 12 months, single-procedure freedom from AF/AT/AFL was 91.3% in those 104 patients off antiarrhythmic drug therapy and 96.2% in those 26 patients on antiarrhythmic drug therapy. Single-procedure freedom from both AF/AT/AFL and antiarrhythmic drug therapy was 73.1%.
This study suggests that an ablation protocol respecting strict criteria for lesion depth and contiguity results in acute durable PV isolation followed by a high single-procedure arrhythmia-free survival at 1 year. A prospective, multicenter trial is ongoing.
Left atrial fibrosis is prominent in patients with atrial fibrillation (AF). Extensive atrial tissue fibrosis identified by delayed enhancement magnetic resonance imaging (MRI) has been associated ...with poor outcomes of AF catheter ablation.
To characterize the feasibility of atrial tissue fibrosis estimation by delayed enhancement MRI and its association with subsequent AF ablation outcome.
Multicenter, prospective, observational cohort study of patients diagnosed with paroxysmal and persistent AF (undergoing their first catheter ablation) conducted between August 2010 and August 2011 at 15 centers in the United States, Europe, and Australia. Delayed enhancement MRI images were obtained up to 30 days before ablation.
Fibrosis quantification was performed at a core laboratory blinded to the participating center, ablation approach, and procedure outcome. Fibrosis blinded to the treating physicians was categorized as stage 1 (<10% of the atrial wall), 2 (≥10%-<20%), 3 (≥20%-<30%), and 4 (≥30%). Patients were followed up for recurrent arrhythmia per current guidelines using electrocardiography or ambulatory monitor recording and results were analyzed at a core laboratory. Cumulative incidence of recurrence was estimated by stage at days 325 and 475 after a 90-day blanking period (standard time allowed for arrhythmias related to ablation-induced inflammation to subside) and the risk of recurrence was estimated (adjusting for 10 demographic and clinical covariates).
Atrial tissue fibrosis estimation by delayed enhancement MRI was successfully quantified in 272 of 329 enrolled patients (57 patients 17% were excluded due to poor MRI quality). There were 260 patients who were followed up after the blanking period (mean SD age of 59.1 10.7 years, 31.5% female, 64.6% with paroxysmal AF). For recurrent arrhythmia, the unadjusted overall hazard ratio per 1% increase in left atrial fibrosis was 1.06 (95% CI, 1.03-1.08; P < .001). Estimated unadjusted cumulative incidence of recurrent arrhythmia by day 325 for stage 1 fibrosis was 15.3% (95% CI, 7.6%-29.6%); stage 2, 32.6% (95% CI, 24.3%-42.9%); stage 3, 45.9% (95% CI, 35.5%-57.5%); and stage 4, 51.1% (95% CI, 32.8%-72.2%) and by day 475 was 15.3% (95% CI, 7.6%-29.6%), 35.8% (95% CI, 26.2%-47.6%), 45.9% (95% CI, 35.6%-57.5%), and 69.4% (95% CI, 48.6%-87.7%), respectively. Similar results were obtained after covariate adjustment. The addition of fibrosis to a recurrence prediction model that includes traditional clinical covariates resulted in an improved predictive accuracy with the C statistic increasing from 0.65 to 0.69 (risk difference of 0.05; 95% CI, 0.01-0.09).
Among patients with AF undergoing catheter ablation, atrial tissue fibrosis estimated by delayed enhancement MRI was independently associated with likelihood of recurrent arrhythmia. The clinical implications of this association warrant further investigation.
Intra- and Interatrial Asynchrony in Patients With Heart Failure Van Beeumen, Katarina, MD; Duytschaever, Mattias, MD, PhD; Tavernier, Rene, MD, PhD ...
The American journal of cardiology,
2007, 2007-Jan-01, 2007-01-00, 20070101, Letnik:
99, Številka:
1
Journal Article
Recenzirano
Heart failure (HF) is associated with atrial conduction delay. Color tissue Doppler imaging was used to evaluate intra- and interatrial asynchrony in patients with HF, patients with structural heart ...disease without HF, and controls. Twenty-three controls (mean age 65 ± 13 years), 29 patients with structural heart disease without HF (mean age 68 ± 9 years), and 29 patients with HF (mean age 67 ± 9 years) were studied. Patients had no histories of atrial fibrillation. Echocardiographic color tissue Doppler imaging of the atria was performed. Measurements below the atrioventricular plane were selected on the right atrial (RA) free wall, interatrial septum (IAS), and left atrial (LA) free wall. The time difference from the onset of the P wave to the onset of the A wave at the right atrium (P-RA), the IAS (P-IAS), and the left atrium (P-LA) was measured. Asynchrony was defined as the differences between P-IAS and P-RA (RA asynchrony), P-LA and P-IAS (LA asynchrony), and P-LA and P-RA (interatrial asynchrony). In patients with HF, a significant increase in RA asynchrony was observed compared with controls and patients without HF (30 ± 21 vs 12 ± 13 and 14 ± 15 ms, p <0.001). LA asynchrony was not different (19 ± 26 vs 25 ± 13 vs 25 ± 14 ms, p = NS). Interatrial asynchrony was significantly increased in patients with HF (49 ± 24 vs 37 ± 9 and 39 ± 17 ms, p = 0.04). There were moderate but significant correlations of RA asynchrony with log N-terminal–pro-B-type natriuretic peptide (r = 0.3, p = 0.01) and the ejection fraction (r = −0.4, p <0.001). In conclusion, in patients with HF, significant RA and interatrial asynchrony was documented, evaluated by noninvasive color tissue Doppler imaging. Asynchrony was related to N-terminal–pro-B-type natriuretic peptide and to the ejection fraction.
'CLOSE'-guided pulmonary vein isolation (PVI) is a point-by-point, contact force (CF)-guided radiofrequency (RF) approach aiming to enclose the PVs with contiguous RF lesions by targeting strict ...criteria for interlesion distance and ablation index (AI). We characterized real-time changes in bipolar (B-EGMs) and unipolar electrograms (U-EGMs) during AI-targeted RF delivery.
EGM changes during 56 RF applications in 7 patients with paroxysmal atrial fibrillation (AF) undergoing 'CLOSE'-guided PVI were studied. CF-guided RF was delivered with 35W targeting an AI of 400 at posterior and 550 at anterior wall. 336 B-EGMs and 336 U-EGMs before, during and after RF delivery were analyzed with their RF characteristics. Amplitude of the B-and U-EGM and morphology of the U-EGM were measured at each 5-second step using custom-made software.
We observed a significant reduction in B-EGM amplitude (0.43 IQR=0.25, 0.55 to 0.11 0.07, 0.22 mV, p<0.001) and U-EGM amplitude (0.57 0.40, 0.87 to 0.22 0.10, 0.34 mV, p<0.001) within 5 seconds, after which no more changes were observed. Impedance drop was 18.3±1.1Ω. Loss of the unipolar terminal S-wave occurred in 59% of applications. There was no correlation between U-EGM morphology changes and RF characteristics.
In AI-guided RF delivery there is a significant reduction in EGM amplitude within 5 seconds. Loss of the unipolar terminal S wave occurred in 59% of applications and was not related to RF characteristics suggestive of adequate lesion formation. These findings suggest that there is a limited value in monitoring electrograms to further optimize 'CLOSE'-guided PVI.
Abstract
Aims
Catheter ablation is indicated in patients with symptomatic paroxysmal atrial fibrillation (AF) resistant to antiarrhythmic drug therapy (ADT). We investigated whether continued use of ...previously ineffective ADT beyond the post-ablation blanking period reduces recurrence of atrial tachyarrhythmia within the 1st year after ablation.
Methods and results
This was a multicentre, randomized controlled study in patients undergoing contact force-guided pulmonary vein isolation (PVI) for paroxysmal AF in whom previously ineffective ADT was continued during a blanking period of 3 months. If free of AF at the end of the blanking period, patients were randomly assigned in the ratio of 1:1 to continue ADT (ADT ON group, n = 77) or discontinue ADT (ADT OFF group, n = 76). Patients were followed up until 1 year after PVI, with clinical visits, Holter monitoring, and quality-of-life (QOL) questionnaires at 6 and 12 months post-procedure. Analysis of the primary endpoint (any documented atrial tachyarrhythmia lasting >30 s) was performed according to the modified intention-to-treat principle. Secondary endpoints included repeat ablation, unscheduled visits, and QOL score. Baseline clinical characteristics and initial ablation procedure characteristics were comparable between both groups. Three patients were lost to follow-up in each arm. The primary endpoint was observed in 2 of 74 (2.7%) patients in the ADT ON group vs. 16 of 73 (21.9%) patients in the ADT OFF group (P < 0.001). The ADT ON group had a lower rate of repeat ablation 1.4% vs. 19.2%, hazard ratio (HR) = 0.053; 95% confidence interval (CI) 0.007–0.399; P < 0.01) and less unscheduled arrhythmia-related health care visits (2.7% vs. 20.5%, HR = 0.055, 95% CI 0.007–0.410; P < 0.01). Quality-of-life scores were similar in both groups.
Conclusion
In patients free of AF at the end of 3 months of post-ablation blanking period, continued use of previously ineffective ADT significantly reduces the recurrence of atrial tachyarrhythmia in the 1st year after PVI.
Pulmonary vein reconnection (PVR) still determines recurrences of atrial fibrillation after contact force (CF)-guided pulmonary vein isolation. We studied whether acute PVR (adenosine and waiting ...time) and late PVR (at repeat) are explained by incomplete transmurality and contiguity within the deployed radiofrequency circle.
We analyzed 42 CF-guided ipsilateral pulmonary vein isolation procedures. For each radiofrequency tag within the circle, we collected data reflecting lesion depth (time of application, power, impedance drop Δ-Imp, CF, force-time integral FTI, and ablation index AI) and contiguity (automated interlesion distance ILD). Ablation line contiguity index (ALCI) was developed as a novel automated algorithm combining depth and contiguity into one single criterion. Each circle was subdivided into 10 segments. For each segment, we determined its weakest link by annotating time
, power
, Δ-Imp
, CF
, FTI
, AI
, ILD
, and ALCI
. Compared with segments without PVR (n=758), PVR segments (n=44) were characterized by lower Δ-Imp
(4.8 versus 7.4 Ω), CF
(8.5 versus 11.8 g), FTI
(351 versus 473 gs), AI
(367 versus 408 arbitrary unit au), and higher ILD
(6.8 versus 5.5 mm). ALCI
was significantly lower in segments with PVR (74% versus 104%;
<0.001) and was associated with the highest accuracy to predict durable segments (area under the curve=0.73).
In CF-guided pulmonary vein isolation, PVR is explained by lack of both lesion depth and contiguity within the deployed radiofrequency circle. ALCI, a novel measure combing contiguity and depth, is the most accurate predictor for durable segments. By avoiding weak links in the ablation chain, ALCI-guided ablation is expected to improve success rate of point-by-point radiofrequency ablation.
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