The interconnected atrium: Acute impact of pulmonary vein isolation on remote atrial tissue.
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ABSTRACT:
SUBMITTER: Rogers AJ
PROVIDER: S-EPMC7500578 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:PurposeReal-time observation of pulmonary vein (PV) potentials with a spiral mapping catheter has emerged as a key electrogram-based procedural parameter to estimate lesion quality and titrate cryoenergy application during PV isolation (PVI) with the cryoballoon. Whether correct PV electrogram interpretation and thus PVI real-time observation rate depends on atrial rhythm during cryoballoon PVI is unknown. We compared observation rates of time-to PV isolation (TTI) during sinus rhythm (SR group) and during atrial fibrillation (AFib group) in cryoballoon PVI.MethodsWe prospectively included 157 consecutive patients undergoing cryoballoon PVI and compared the incidence of PVI real-time recording of each pulmonary vein during SR and in AFib.ResultsOverall PVI real-time observation rate was 82.1% (491/598 PV) with significantly higher TTI observation rate in the SR group (315/365 PV, 86.3%) compared to the AFib group (176/233 PV, 75.5%; p < 0.001). Per vein analysis demonstrated that only TTI observation rate in the left superior pulmonary vein (LSPV) was significantly higher during SR (85/92, 92.4%) compared to AFib (37/54, 68.5%; p < 0.001). Regression analysis revealed that atrial rhythm is a strong and independent predictor of PVI real-time observation in the LSPV with an odds ratio of 4.98 (95%-CI: 1.86-13.34, p = 0.001) to detect TTI during SR.ConclusionsOur results demonstrate that correct interpretation of PV electrograms and thus PVI real-time observation is more likely in SR than in AFib. Hence, cardioversion of patients in AFib at the beginning of the procedure should be considered to yield higher PVI real-time observation rates facilitating TTI guided cryoenergy titration.
| S-EPMC6495074 | biostudies-literature
Project description:Electrical activation during atrial fibrillation (AF) appears chaotic and disorganised, which impedes characterisation of the underlying substrate and treatment planning. While globally chaotic, there may be local preferential activation pathways that represent potential ablation targets. This study aimed to identify preferential activation pathways during AF and predict the acute ablation response when these are targeted by pulmonary vein isolation (PVI). In patients with persistent AF (n = 14), simultaneous biatrial contact mapping with basket catheters was performed pre-ablation and following each ablation strategy (PVI, roof, and mitral lines). Unipolar wavefront activation directions were averaged over 10 s to identify preferential activation pathways. Clinical cases were classified as responders or non-responders to PVI during the procedure. Clinical data were augmented with a virtual cohort of 100 models. In AF pre-ablation, pathways originated from the pulmonary vein (PV) antra in PVI responders (7/7) but not in PVI non-responders (6/6). We proposed a novel index that measured activation waves from the PV antra into the atrial body. This index was significantly higher in PVI responders than non-responders (clinical: 16.3 vs. 3.7%, p = 0.04; simulated: 21.1 vs. 14.1%, p = 0.02). Overall, this novel technique and proof of concept study demonstrated that preferential activation pathways exist during AF. Targeting patient-specific activation pathways that flowed from the PV antra to the left atrial body using PVI resulted in AF termination during the procedure. These PV activation flow pathways may correspond to the presence of drivers in the PV regions.
| S-EPMC8503618 | biostudies-literature
Project description:BackgroundRelevant atrial cardiomyopathy (ACM), defined as a left atrial (LA) low-voltage area ≥ 2 cm2 at 0.5 mV threshold on endocardial contact mapping, is associated with new-onset atrial fibrillation (AF), higher arrhythmia recurrence rates after pulmonary vein isolation (PVI), and an increased risk of stroke. The current study aimed to assess two non-invasive echocardiographic parameters, LA emptying fraction (EF) and LA longitudinal strain (LAS, during reservoir (LASr), conduit (LAScd) and contraction phase (LASct)) for the diagnosis of ACM and prediction of arrhythmia outcome after PVI.MethodsWe prospectively enrolled 60 consecutive, ablation-naive patients (age 66 ± 9 years, 80% males) with persistent AF. In 30 patients (derivation cohort), LA-EF and LAS cut-off values for the presence of relevant ACM (high-density endocardial contact mapping in sinus rhythm prior to PVI at 3000 ± 1249 sites) were established in sinus rhythm and tested in a validation cohort (n = 30). Arrhythmia recurrence within 12 months was documented using 72-h Holter electrocardiograms.ResultsAn LA-EF of < 34% predicted ACM with an area under the curve (AUC) of 0.846 (sensitivity 69.2%, specificity 76.5%) similar to a LASr < 23.5% (AUC 0.878, sensitivity 92.3%, specificity 82.4%). In the validation cohort, these cut-offs established the correct diagnosis of ACM in 76% of patients (positive predictive values 87%/93% and negative predictive values 73%/75%, respectively). Arrhythmia recurrence in the entire cohort was significantly more frequent in patients with LA-EF < 34% and LASr < 23.5% (56% vs. 29% and 55% vs. 26%, both p < 0.05).ConclusionThe echocardiographic parameters LA-EF and LAS allow accurate, non-invasive diagnosis of ACM and prediction of arrhythmia recurrence after PVI.
| S-EPMC8563528 | biostudies-literature
Project description:BackgroundAcute pulmonary vein reconnection (PVR) is associated with long procedure times and large radiofrequency (RF) energy delivery during pulmonary vein isolation (PVI). Although the efficacy of high-power PVI (HP-PVI) has been recently established, the determinants of acute PVR following HP-PVI remain unclear.MethodsWe evaluated data on 62 patients with paroxysmal atrial fibrillation undergoing unipolar signal modification (USM)-guided HP-PVI. A 50-W RF wave was applied for 3-5 seconds after USM. In the segments adjacent to the esophagus (SAEs), the RF time was limited to 5 seconds. Each circle was subdivided into six regions (segments), and the possible predictors of acute PVR, including minimum contact force (CFmin), minimum force-time integral (FTImin), minimum ablation index (AImin), minimum impedance drop (Imp-min), and maximum inter-lesion distance (ILDmax), were assessed in each segment.ResultsWe investigated 1162 ablations in 744 segments (including 124 SAEs). Acute PVR was observed in 21 (17%) SAEs and 43 (7%) other segments (P = .001). The acute PVR segments were characterized by significantly lower CFmin, FTImin, AImin, and Imp-min values in the segments other than the SAEs and larger ILDmax values in the SAEs. Furthermore, lower Imp-min and larger ILDmax values independently predicted acute PVR in the segments other than the SAEs and SAEs (odds ratios 0.90 and 1.39 respectively). Acute PVR was not significantly associated with late atrial fibrillation recurrence.ConclusionsAvoiding PVR remains a challenge in HP-PVI cases, but it might be resolved by setting the optimal target impedance drop and lesion distance values.
| S-EPMC8485794 | biostudies-literature
Project description:This article reviews methods for lesion set assessment during radiofrequency catheter ablation for atrial fibrillation (AF). Pulmonary vein isolation (PVI) is the foundation for AF ablation, but PV reconnection can lead to treatment failure. Testing for entrance block can help confirm PVI, although complex electrograms that consist of both near- and far-field potentials may make assessment of entrance block challenging. Differential pacing maneuvers can help appropriately identify PV potentials. After entrance block has been achieved, pacing within the PVs to demonstrate capture of PV musculature with exit block may also help to confirm completeness of lesion sets for PVI. Employing a waiting period of at least 30 min or administering adenosine or isoproterenol can reveal dormant conduction, warranting adjunctive ablation. Additional techniques to confirm durable PVI include testing the ablation lines for excitability with high amplitude pacing, and automated waveform analysis of local electrogram morphology. Newer techniques like real-time magnetic resonance imaging and acoustic radiation force impulse elastography may have a role in testing the completeness of lesion sets in the future.
| S-EPMC7252765 | biostudies-literature
Project description:BackgroundGanglionated plexuses (GPs) are implicated in atrial fibrillation (AF). Endocardial high-frequency stimulation (HFS) delivered within the local atrial refractory period can trigger ectopy and AF from specific GP sites (ET-GP). The aim of this study was to understand the role of ET-GP ablation in the treatment of AF.MethodsPatients with paroxysmal AF indicated for ablation were recruited. HFS mapping was performed globally around the left atrium to identify ET-GP. ET-GP was defined as atrial ectopy or atrial arrhythmia triggered by HFS. All ET-GP were ablated, and PVs were left electrically connected. Outcomes were compared with a control group receiving pulmonary vein isolation (PVI). Patients were followed-up for 12 months with multiple 48-h Holter ECGs. Primary endpoint was ≥30 s AF/atrial tachycardia in ECGs.ResultsIn total, 67 patients were recruited and randomized to ET-GP ablation (n = 39) or PVI (n = 28). In the ET-GP ablation group, 103 ± 28 HFS sites were tested per patient, identifying 21 ± 10 (20%) GPs. ET-GP ablation used 23.3 ± 4.1 kWs total radiofrequency (RF) energy per patient, compared with 55.7 ± 22.7 kWs in PVI (p = <.0001). Duration of procedure was 3.7 ± 1.0 and 3.3 ± 0.7 h in ET-GP ablation group and PVI, respectively (p = .07). Follow-up at 12 months showed that 61% and 49% were free from ≥30 s of AF/AT with PVI and ET-GP ablation respectively (log-rank p = .27).ConclusionsIt is feasible to perform detailed global functional mapping with HFS and ablate ET-GP to prevent AF. This provides direct evidence that ET-GPs are part of the AF mechanism. The lower RF requirement implies that ET-GP targets the AF pathway more specifically.
| S-EPMC8611799 | biostudies-literature
Project description:The pathophysiology of non-pulmonary vein (PV) triggers of atrial fibrillation (AF) is unclear. We hypothesized that left atrial non-PV (LANPV) triggers are associated with atrial tissue degeneration. This study analyzed 431 patients that underwent catheter ablation (mean age 62?yrs, 303 men, 255 paroxysmal AF [pAF] patients). Clinical and electrophysiological characteristics of non-PV trigger were analyzed. Fifty non-PV triggers in 40 patients (9.3%) were documented; LANPV triggers were the most prevalent (n?=?19, 38%). LANPV triggers were correlated with non-paroxysmal AF (non-pAF) (OR 3.31, p?=?0.04) whereas right atrial non-PV (RANPV) triggers (n?=?14) and SVC triggers (n?=?17) were not. The voltage at the LANPV sites during SR was 0.3?±?0.16?mV (p?<?0.001 vs. control site). Low-voltage areas (LVAs) in the LA were significantly greater in non-pAF compared to pAF (14.2% vs. 5.8%, p?<?0.01). RANPV trigger sites had preserved voltage (0.74?±?0.48?mV). Long-term outcomes of patients with non-PV triggers treated with tailored targeting strategies were not significantly inferior to those without non-PV triggers. In conclusion, non-PV triggers arise from the LA with degeneration, which may have an important role in AF persistence. A trigger-oriented, patient-tailored ablation strategy considering LA voltage map may be feasible and effective in persistent/recurrent AF.
| S-EPMC6706423 | biostudies-literature
Project description:Epicardial adipose tissue (EAT) has been recognized as a sensitive marker of cardiometabolic risk. Recent evidence suggests efficacy of long-term statin therapy in reducing EAT in patients with coronary artery disease. Whether short-term statin therapy is associated with changes in the volume of EAT is currently unknown. A cohort of patients with atrial fibrillation who underwent pulmonary vein isolation were randomized to receive either 80 mg/day of atorvastatin (n = 38, 32 men, age 56 ± 11 years) or placebo (n = 41, 33 men, age 56 ± 10 years) for a 3-month period. EAT volume was assessed by cardiac computed tomography at baseline and at follow-up. Patients randomized to statin treatment exhibited a modest but significant decrease in median EAT volume (baseline vs follow-up: 92.3 cm(3) [62.0 to 133.3] vs 86.9 cm(3) [64.1 to 124.8], p <0.05), whereas median EAT remained unchanged in the placebo group (81.9 cm(3) [55.5 to 110.9] vs 81.3 cm(3) [57.1 to 110.5], p = NS). Changes in median systemic inflammatory markers and lipid profile were also seen with statin treatment: C-reactive protein (2.4 mg/L [0.7 to 3.7] vs 1.1 mg/L [0.5 to 2.7], p <0.05), total cholesterol (186 mg/dL [162.5 to 201] vs 123 mg/dL [99 to 162.5], p <0.001), and low-density lipoprotein cholesterol (116 mg/dL [96.5 to 132.5] vs 56 [40.5 to 81] mg/dL, p <0.001) diminished, whereas median body mass index did not change (27.8 kg/m(2) [25 to 30] versus 27.6 kg/m(2) [25.7 to 30.5], p = NS). No variations occurred in the placebo group. In conclusion, short-term intensive statin therapy significantly reduced the volume of EAT in patients with atrial fibrillation.
| S-EPMC4609296 | biostudies-literature
Project description:OBJECTIVE:To investigate mechanisms by which atrial fibrillation (AF) may terminate during ablation near the pulmonary veins before the veins are isolated (PVI). INTRODUCTION:It remains unstudied how AF may terminate during ablation before PVs are isolated, or how patients with PV reconnection can be arrhythmia-free. We studied patients in whom PV antral ablation terminated AF before PVI, using two independent mapping methods. METHODS:We studied patients with AF referred for ablation, in whom biatrial contact basket electrograms were studied by both an activation/phase mapping method and by a second validated mapping method reported not to create false rotational activity. RESULTS:In 22 patients (age 60.1 ± 10.4, 36% persistent AF), ablation at sites near the PVs terminated AF (77% to sinus rhythm) prior to PVI. AF propagation revealed rotational (n = 20) and focal (n = 2) patterns at sites of termination by mapping method 1 and method 2. Both methods showed organized sites that were spatially concordant (P < 0.001) with similar stability (P < 0.001). Vagal slowing was not observed at sites of AF termination. DISCUSSION:PV antral regions where ablation terminated AF before PVI exhibited rotational and focal activation by two independent mapping methods. These data provide an alternative mechanism for the success of PVI, and may explain AF termination before PVI or lack of arrhythmias despite PV reconnection. Mapping such sites may enable targeted PV lesion sets and improved freedom from AF.
| S-EPMC5980723 | biostudies-literature
Project description:BackgroundThe interpretation of recent trials on pulmonary vein ablation (PVI) for the treatment of atrial fibrillation (AF) is hampered by the lack of blinding and sham controls. The feasibility of a sham-controlled trial has been questioned. We aimed to assess the attitude of potential participants regarding a sham-controlled trial in a common AF-patient population planned for PVI.MethodsPatients in two tertiary care centres planned for PVI were asked for their current AF symptoms using the Atrial Fibrillation Effect on QualiTy of Life (AFEQT) questionnaire 1 day before catheter ablation. Subsequently, the study design of a hypothetical sham-controlled PVI-study was introduced, and patients were asked for their agreement in participation. Telephone follow-up of the AFEQT questionnaire was conducted 3 months after PVI.ResultsOne hundred and ninety-six patients (mean age 64 ± 11 years, 63% male) were included. Seventy-nine (40%) patients expressed their agreement to participate in the hypothetical sham-controlled trial. An additional 7% agreed to participate if a cross-over option after three months was offered. Agreement rate was similar in patients with first and Redo-PVI and minimal, moderate or severe symptoms. Mean overall AFEQT at baseline was 55 ± 19 and improved by 25 ± 20 points after 3 months (p < 0.001 versus baseline).ConclusionWith a participation rate of 40% in potential study participants, a sham-controlled trial for pulmonary vein isolation seems feasible. Patient-reported symptom relief after pulmonary vein isolation is in accordance with previous randomized open studies. The benefit of PVI should be rigorously evaluated in a sham-controlled trial.
| S-EPMC8766391 | biostudies-literature