Aim: To optimize recommendations for programming of the rate-adaptive atrioventricular (AV) delay.
Methods And Results: Optimal AV delay (AVD(opt)) is the net effect of the pacemaker-related interatrial conduction time (IACT), duration of the left-atrial electromechanical action (LA-EAC(long)) and duration of left-ventricular latency (S(V)-EAC(short)). It can be calculated by AVD(opt) = IACT + LA-EAC(long)-S(V)-EAC(short). We measured these three components in 20 DDD pacemaker patients (EF >45%) with the third degree AV block (AVB) at rest and submaximal ergometric exercise load of 71 +/- 9 W which resulted in a 31.5 +/- 9.9 bpm rate increase. Between exercise and rest, the components of and the final AVD(opt) showed no significant differences. Interatrial conduction time in VDD and DDD pacing varied by 2.3 +/- 8.4 ms and 1.4 +/- 8.8 ms, respectively, S(V)-EAC(short) changed by -2.6 +/- 21.8 ms and AVD(opt) by -3.5 +/- 33.3 ms and -4.3 +/- 37.8 ms in VDD and DDD operation, respectively. The greatest variation was of LA-EAC(long) by -8.4 +/- 32.7 ms. Linear regressions of the rate-dependent variations (Deltaf) in VDD operation yielded DeltaIACT(f) = 0.04Deltaf + 0.95 ms, DeltaLA-EAC(long) = -0.59Deltaf + 10.1 ms, and DeltaS(V) - EAC(short) = 0.14Deltaf -7.2 ms which resulted in DeltaAVD(opt) = -0.69Deltaf + 18.2 ms.
Conclusion: A recommendation for programming of rate-adaptive AV delay in AV block patients cannot be given.
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http://dx.doi.org/10.1093/europace/eum022 | DOI Listing |
Europace
July 2024
ASST Rhodense, Rho & Garbagnate Hospitals, Viale Carlo Forlanini, 95, 20024 Garbagnate Milanese, Milan, Italy.
J Interv Card Electrophysiol
December 2023
Division of Cardiology, Medical University of South Carolina, 30 Courtenay Drive, MSC 592, Charleston, SC, 29425, USA.
Background: Intrinsic atrioventricular (AV) conduction is used to optimize AV intervals with cardiac resynchronization therapy (CRT) in most device algorithms. Atrial pacing and heart rate affect conduction times, but little is known regarding differeces among chronotropic incompetent(CI) and competent(CC) patients to guide programming.
Methods: RAVE was a multicenter prospective trial of CRT patients.
Pacing Clin Electrophysiol
September 2023
Department of Cardiology, Barts Heart Centre, Barts Health NHS Trust, London, UK.
Effective rate-adaptive pacing may be difficult in the presence of atrial fibrillation (AF), and is important during high-intensity exercise. This case presents a 74-year-old elite cyclist with AF and a biventricular pacemaker after atrioventricular (AV) node ablation. He reported sudden breathlessness due to heart rate drops, caused by breaching the artefact threshold on the minute-ventilation sensor.
View Article and Find Full Text PDFJ Vet Cardiol
October 2022
Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada. Electronic address:
Introduction: In dogs, single lead ventricular pacing, ventricular sensing, inhibition response, rate adaptive (VVIR) pacemakers are routinely used to treat third degree atrioventricular block. The objectives of this study were to investigate the heart rate distribution in dogs with VVIR pacemakers, and report changes when activity settings were adjusted.
Animals: Eighteen client-owned dogs with VVIR pacemakers for third degree atrioventricular block.
J Vet Intern Med
November 2021
Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Merelbeke, Belgium.
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