Use of an Atrial Lead with Very Short Tip-To-Ring Spacing Avoids Oversensing of Far-Field R-Wave

The AVOID-FFS (Avoidance of Far-Field R-wave Sensing) study aimed to investigate whether an atrial lead with a very short tip-to-ring spacing without optimization of pacemaker settings shows equally low incidence of far-field R-wave sensing (FFS) when compared to a conventional atrial lead in combination with optimization of the programming.Patients receiving a dual chamber pacemaker were randomly assigned to receive an atrial lead with a tip-to-ring spacing of 1.1 mm or a lead with a conventional tip-to-ring spacing of 10 mm. Postventricular atrial blanking (PVAB) was programmed to the shortest possible value of 60 ms in the study group, and to an individually determined optimized value in the control group. Atrial sensing threshold was programmed to 0.3 mV in both groups. False positive mode switch caused by FFS was evaluated at one and three months post implantation.A total of 204 patients (121 male; age 73±10 years) were included in the study. False positive mode switch caused by FFS was detected in one (1%) patient of the study group and two (2%) patients of the control group (p = 0.62).The use of an atrial electrode with a very short tip-to-ring spacing avoids inappropriate mode switch caused by FFS without the need for individual PVAB optimization.ClinicalTrials.gov NCT00512915

Single-procedure outcomes and quality-of-life improvement 12 months post-cryoballoon ablation in persistent atrial fibrillation : results from the multicenter CRYO4PERSISTENT AF trial

Objectives: The CRYO4PERSISTENT AF (Cryoballoon Ablation for Early Persistent Atrial Fibrillation) trial aims to report long-term outcomes after a single pulmonary vein isolation (PVI)–only ablation procedure using the second-generation cryoballoon in persistent atrial fibrillation (PerAF) patients. Background: Pulmonary vein isolation is recognized as the cornerstone of atrial fibrillation (AF) ablation, including ablation of PerAF. Methods: The CRYO4PERSISTENT AF trial (NCT02213731) is a prospective, multicenter, single-arm trial designed to assess single-procedure outcomes of PVI using the cryoballoon. The primary endpoint was freedom from AF, atrial flutter, or atrial tachycardia ≥30 s after a 90-day blanking period. After enrollment, but before ablation, patients without 100% AF burden (18-h Holter monitoring or 3 consecutive electrocardiograms in a time frame ≥14 days) were excluded. Patients were followed at 3, 6, and 12 months, with 48-h Holter monitoring at 6 and 12 months. Quality of life and symptoms were evaluated at baseline and 12 months. Arrhythmia recurrence and adverse events were adjudicated by an independent committee. Results: A total of 101 patients (62 ± 11 years of age, 74% men, left ventricular ejection fraction 56 ± 8%, left atrial diameter 43 ± 5 mm) meeting criteria, undergoing cryoballoon-based PVI, with follow-up data, were included. Kaplan-Meier estimate of freedom from AF, atrial flutter, or atrial tachycardia recurrence was 60.7% at 12 months. Compared with baseline, there were significantly fewer patients with arrhythmia-related symptoms at 12 months (16% vs. 92%; p < 0.0001). The symptom reduction was supported by significant improvement in 36-Item Short Form Health Survey composite scores and European Heart Rhythm Association score at 12 months. The only device related event was transient phrenic nerve injury in 2 (2%) patients, with resolution pre-discharge. Conclusions: Cryoballoon ablation for treatment of PerAF demonstrated 61% single-procedure success at 12 months post-ablation in addition to significant reduction in arrhythmia-related symptoms and improved quality of life. (Cryoballoon Ablation for Early Persistent Atrial Fibrillation [Cryo4 Persistent AF]; NCT02213731

Distribution of programmed PVAB during follow-up by randomization groups.

<p>Nine patients of the study group initially received a PVAB that was erroneously programmed to a value other than 60 ms which was corrected after one month in eight of the patients and remained prolonged in one patient. None of these patients had inappropriate mode switch due to FFS. One patient of the study group patient exhibited inappropriate mode switch due to FFS and the PVAB was then individually optimized (150 ms). For the control group PVAB is shown as determined to be optimal at discharge. In case of changes of the PVAB programming during the follow-up, the longest programmed PVAB for both groups are displayed.</p

Electrical parameters of the atrial leads.

<p>Electrical parameters of the atrial leads.</p

Study flow-chart.

<p>Study flow-chart.</p