Background
Pulmonary vein isolation (PVI) using high power delivered by SmartTouch Surround Flow (STSF) catheters guided by ablation index (AI) was evaluated in a multicenter registry.
Methods
...Patients with paroxysmal AF underwent PVI with STSF catheters using 30 W on the posterior wall and 40 W elsewhere. AI targets were 350 posterior walls and 450 elsewhere. Procedures were compared with controls using conventionally irrigated contact force‐sensing catheters using conventional powers (25 W posterior wall and 30 W elsewhere) guided by force‐time integral (no agreed targets). The waiting period of 30 minutes was observed before adenosine administration to assess acute pulmonary vein (PV) reconnection.
Results
One hundred patients from four centers were included: 50 patients in the high power ablation index (HPAI) group and 50 controls. Procedure time was 22% shorter in the HPAI group (156 133.8‐179 vs 199 178.5‐227 minutes; P < 0.001). Duration of the radiofrequency application was 37% shorter in the HPAI group (27.2 21.5‐35.8 vs 43.2 35.1‐52.1 minutes;
P < 0.001). Acute PV reconnection was reduced (28 of 200 14% vs 48 of 200 24% veins;
P = 0.015). Reconnection was predicted by a largest interlesion distance greater than 6 mm, a lesion with impedance drop less than 2.5 Ω, contact force less than 6 g, or less than 68% of the regional AI target (all
P < 0.001). Freedom from atrial arrhythmia at 1 year off antiarrhythmic drugs after a single procedure was 78% in the HPAI group vs 64% in the control group (
P = 0.186).
Conclusion
High‐powered ablation guided by AI was safe and led to shorter procedure times with reduced acute PV reconnection compared with conventional ablation.
Human T-lymphotropic virus type 1 (HTLV-1), a retrovirus, is the causative agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T-cell leukaemia/lymphoma (ATLL). The ...reported association with pulmonary disease such as bronchiectasis is less certain.
A retrospective case review of a HTLV-1 seropositive cohort attending a national referral centre. The cohort was categorised into HTLV-1 symptomatic patients (SPs) (ATLL, HAM/TSP, Strongyloidiasis and HTLV associated inflammatory disease (HAID)) and HTLV-1 asymptomatic carriers (ACs). The cohort was reviewed for diagnosis of bronchiectasis.
34/246 ACs and 30/167 SPs had been investigated for respiratory symptoms by computer tomography (CT) with productive cough +/- recurrent chest infections the predominant indications. Bronchiectasis was diagnosed in one AC (1/246) and 13 SPs (2 HAID, 1 ATLL, 10 HAM/TSP) (13/167, RR 19.2 95 % CI 2.5-14.5, p = 0.004) with high resolution CT. In the multivariate analysis ethnicity (p = 0.02) and disease state (p < 0.001) were independent predictors for bronchiectasis. The relative risk of bronchiectasis in SPs was 19.2 (95 % CI 2.5-14.5, p = 0.004) and in HAM/TSP patients compared with all other categories 8.4 (95 % CI 2.7-26.1, p = 0.0002). Subjects not of African/Afro-Caribbean ethnicity had an increased prevalence of bronchiectasis (RR 3.45 95 % 1.2-9.7, p = 0.02).
Bronchiectasis was common in the cohort (3.4 %). Risk factors were a prior diagnosis of HAM/TSP and ethnicity but not HTLV-1 viral load, age and gender. The spectrum of HTLV-associated disease should now include bronchiectasis and HTLV serology should be considered in patients with unexplained bronchiectasis.
Introduction
Identifying drivers in persistent atrial fibrillation (AF) remains challenging. We sought to validate an automated system for detection of focal activation using basket and PentaRay ...catheters in AF.
Methods
Patients having ablation for atrial tachycardia (AT) and persistent AF were mapped. Thirty‐second unipolar basket and PentaRay recordings were analyzed using CARTOFINDER. Focal activation or “region of interest” (ROI) was defined as more than or equal to 2 consecutive focal activations with one electrode leading relative to its neighbors with QS morphology on the unipolar electrogram. ROI was validated in AT. AF patients were mapped to (1) look for evidence of focal activations on wavefront maps, (2) evaluate whether these were detected as ROI on basket recordings, and (3) whether these sites could be identified on sequential PentaRay recordings.
Results
ROIs were identified in five focal ATs but none of 16 reentrant ATs. Twenty‐eight AF patients had 35 focal drivers identified from basket wavefront maps with an ablation response in all (16 cycle length slowing and 19 AF termination). Thirty focal activations were detected on basket ROI maps (86%). Twenty‐three of 28 patients had sequential PentaRay mapping and 22 of 30 focal drivers in these patients (73%) were identified as ROI. These drivers had greater temporal stability (3.6 ± 0.6 vs 2.7 ± 0.6; P < 0.001), higher recurrence rate (12.4 ± 2.7 vs 7.2 ± 0.9;
P < 0.001), and more frequently were associated with AF termination (
P < 0.001) compared with those not identified as ROI.
Conclusions
Focal activations can be detected in AF using sequential recordings. The ablation response at focal sources suggests they may be viable therapeutic targets.
We evaluated the effect of adenosine upon mechanisms sustaining persistent AF through analysis of contact electrograms and ECGI mapping.
Persistent AF patients undergoing catheter ablation were ...included. ECGI maps and cycle length (CL) measurements were recorded in the left and right atrial appendages and repeated following boluses of 18 mg of intravenous adenosine. Potential drivers (PDs) were defined as focal or rotational activations completing ≥ 1.5 revolutions. Distribution of PDs was assessed using an 18 segment biatrial model.
46 patients were enrolled. Mean age was 63.4 ± 9.8 years with 33 (72%) being male. There was no significant difference in the number of PDs recorded at baseline compared to adenosine (42.1 ± 15.2 vs 40.4 ± 13.0; p = 0.417), nor in the number of segments harbouring PDs, (13 (11-14) vs 12 (10-14); p = 0.169). There was a significantly higher percentage of PDs that were focal in the adenosine maps (36.2 ± 15.2 vs 32.2 ± 14.4; p < 0.001). There was a significant shortening of CL in the adenosine maps compared to baseline which was more marked in the right atrium than left atrium (176.7 ± 34.7 vs 149.9 ± 27.7 ms; p < 0.001 and 165.6 ± 31.7 vs 148.3 ± 28.4 ms; p = 0.003).
Adenosine led to a small but significant shortening of CL which was more marked in the right than left atrium and may relate to shortening of refractory periods rather than an increase in driver burden or distribution. Registered on Clinicaltrials.gov: NCT03394404.
To assess the prevalence of short corrected QT (QTc) intervals and its impact on short QT syndrome (SQTS) diagnosis using different QT correction formulae.
Observational study. The prevalence of ...short QTc intervals was estimated using four different QT correction formulae in 14 662 young adults from the 'Sudden Cardiac Death Screening of Risk FactOrS' (SCD-SOS) cohort. Then, using data from this cohort and the pooled-cohort analysed by Gollob
, comprising 61 patients with SQTS, we assessed the impact of the different QTc correction formulae on SQTS probability and diagnosis based on the Expert Consensus recommendations (QTc ≤330 ms or QTc 330-360 ms+1 additional risk feature).
The prevalence of individuals with a QTc ≤330 and ≤320 ms in the SCD-SOS cohort was extremely low (≤0.07% and≤0.02%, respectively), and these were more frequently identified by the Framingham correction. The different QTc correction formulae led to a shift in SQTS probability in 5%-10% of individuals in both the SCD-SOS and Gollob cohort). Intermediate probability individuals were rare (<0.1%), and no high-SQTS probability individuals were identified in the SCD-SOS cohort. Based on Consensus criteria, instead of 12 (0.08%) individuals being diagnosed with SQTS using the
equation, a different number of individuals would meet diagnostic criteria with the other formulae: 11 (0.08%) using
, 9 (0.06%) with
and 16 (0.11%) using the
equation.
Prevalence of SQTS in the apparently healthy adult population is low. Applying different QTc correction formulae leads to significant reclassification of SQTS probability and their impact on predicting outcomes should be assessed.
Background Outcomes of catheter ablation of atrial fibrillation (AF) are variable and the predictors of success require further elucidation since the identification of correctable risk factors could ...help to optimize therapy. We aimed to assess the impact of body mass index (BMI) in the overall safety and efficacy of catheter ablation of AF, with emphasis on the use of cryoballoon ablation and novel oral anticoagulants. Methods and Results There were 2497 consecutive patients undergoing catheter ablation of AF in 7 European high volume centers were stratified according to BMI (normal weight <25 kg/m
, pre-obese 25-30 kg/m
, obesity 30-35 kg/m
, and morbid obesity ≥35 kg/m
) and comparisons of procedural outcomes evaluated. Pre-obese and obese patients presented more comorbidities (hypertension, diabetes mellitus, and sleep apnea), and had higher rates of non-paroxysmal AF ablation procedures. The rate of atrial 12-month arrhythmia relapse increased alongside with BMI (35.2%, 35.7%, 43.6%, and 48.0%
<0.001). During a median follow-up of 18.8 months (interquartile range 11-28), after adjusting for all baseline differences, BMI was an independent predictor of relapse (hazard ratio=1.01 per kg/m
; 95% CI 1.01-1.02;
=0.002), adding incremental predictive value to obstructive sleep apnea. BMI was not a predictor for any of the reported complications. Using novel oral anticoagulants and cryoballoon ablation was safe and efficacy was comparable with vitamin-K antagonists and radiofrequency ablation. Conclusions Obese patients present with a more adverse comorbidity profile, more advanced forms of AF, and have lower chances of being free from AF relapse after ablation. Use of novel oral anticoagulants and cryoballoon ablation may be an option in this patient group.
The coronavirus disease 2019 (COVID-19) pandemic has had a dramatic impact on the way that medical care is delivered. To minimise hospital attendance by both patients and staff, remote clinics, ...meetings and investigations have been used. Technologies including hand-held ECG monitoring using smartphones, patch ECG monitoring and sending out conventional Holter monitors have aided remote investigations. Platforms such as Google Meet and Zoom have allowed remote multidisciplinary meetings to be delivered effectively. The use of phone consultations has allowed outpatient care to continue despite the pandemic. The COVID-19 pandemic has resulted in a radical, and probably permanent, change in the way that outpatient care is delivered. Previous experience in remote review and the available technologies for monitoring have allowed the majority of outpatient care to be conducted without obviously compromising quality or safety.
Mechanisms sustaining persistent atrial fibrillation (AF) remain unclear.
The study sought to evaluate both the clinical outcomes and response to ablation of potential drivers in patients with ...recurrent persistent AF recurrence following pulmonary vein isolation (PVI).
A total of 100 patients with persistent AF of <2 years’ duration underwent cryoballoon PVI (ECGI phenotyping of persistent AF based on driver burden and distribution to predict response to pulmonary vein isolation). Patients with documented recurrence of atrial arrhythmia within 12 months were recruited and underwent repeat PVI (if needed) followed by ablation of potential drivers (PDs) identified by electrocardiographic imaging (ECGI). PDs were defined as rotational activity >1.5 revolutions or focal activations. Cycle lengths were measured pre- and postablation. The primary outcome was freedom from atrial arrhythmia off antiarrhythmic drugs at 1 year as per guidelines.
Of 37 patients recruited, 26 had recurrent AF and underwent ECGI-guided ablation of PDs. An average of 6.4 ± 2.7 PDs were targeted per patient. The mean ablation time targeting PDs was 15.5 ± 6.9 minutes. An ablation response occurred in 20 patients (AF termination in 6, cycle length prolongation ≥10% in 14). At 1 year, 14 (54%) of 26 patients were free from arrhythmia, and 12 (46%) of 26 were off antiarrhythmic drugs. Considering the 96 patients who completed follow-up out of the original cohort of 100 patients undergoing cryoablation in this staged strategy, freedom from arrhythmia at 1 year following the last procedure was 72 (75%) of 96, or 70 (73%) of 96 off antiarrhythmic drugs.
In patients with recurrent AF despite PVI, ECGI-guided ablation caused an acute response in a majority with reasonable long-term outcomes.
Established primary prevention strategies of cardiovascular diseases are based on understanding of risk factors, but whether the same risk factors are associated with atrial fibrillation (AF) remains ...unclear. We conducted a systematic review and field synopsis of the associations of 23 cardiovascular risk factors and incident AF, which included 84 reports based on 28 consented and four electronic health record cohorts of 20,420,175 participants and 576,602 AF events. We identified 3-19 reports per risk factor and heterogeneity in AF definition, quality of reporting, and adjustment. We extracted relative risks (RR) and 95 % confidence intervals CI and visualised the number of reports with inverse (RR CI<1.00), or direct (RR CI>1.00) associations. For hypertension (13/17 reports) and obesity (19/19 reports), there were direct associations with incident AF, as there are for coronary heart disease (CHD). There were inverse associations for non-White ethnicity (5/5 reports, with RR from 0.35 to 0.84 0.82-0.85), total cholesterol (4/13 reports from 0.76 0.59-0.98 to 0.94 0.90-0.97; 8/13 reports with non-significant inverse associations), and diastolic blood pressure (2/11 reports from 0.87 0.78-0.96 to 0.92 0.85-0.99; 5/11 reports with non-significant inverse associations), and direct associations for taller height (7/10 reports from 1.03 1.02-1.05 to 1.92 1.38-2.67), which are in the opposite direction of known associations with CHD. A systematic evaluation of the available evidence suggests similarities as well as important differences in the risk factors for incidence of AF as compared with other cardiovascular diseases, which has implications for the primary prevention strategies for atrial fibrillation.
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