RT-24
|
Significant reduction of atrial
floating pacing capture thresholds using a conventional monophasic impulse and a novel
pacing electrode configuration.
First results
|
|
|
W.M. Hartung, D. Hartung, A.
Auricchio, C. Geller, A. Goette, H.-D. Esperer, S. Hobrack, H. Klein.
University Hospital Magdeburg, Department of Internal Medicine, Division of Cardiology,
Magdeburg, Germany
|
|
Abstract
|
|
Single lead, dual-chamber pacing using floating atrial
ring electrodes and a conventional monophasic impulse configuration is limited by
unacceptably high atrial capture thresholds. Our recently described "Overlapping
Biphasic Impulse" (OLBI)-stimulation technique is able to reduce atrial floating
capture thresholds significantly. We further developed a new pacing configuration applying
a conventional impulse between three electrodes delivered bidirectionaly (Bidirectional
Monophasic Impulse or BIMOS).
Methods. In 6 female mini-pigs (27.5 ± 3.5 kg), a modified
single-VDD-lead with three atrial electrodes (interelectrode distance 10 mm) was
introduced under fluoroscopic control so that the ring electrodes were floating in the mid
right atrium. Atrial capture thresholds (ACT) using BIMOS pacing were compared to
conventional bipolar (BI) and unipolar (UI) pacing with identical pulse durations of 0.5
ms. The BIMOS configuration was then tested in 28 patients (14 women, 14 men, mean age 56
± 14 years) during a routine EP-study. A conventional quadripolar electrode catheter was
inserted into the right atrium with the ring electrodes floating in the high and mid-level
of the right atrium. ACTs with BIMOS configuration were compared with ACTs during UI and
BI pacing.
Results. In the animal model, the mean ACT during BIMOS configuration
was significantly lower than during UI (1.8 V vs 1.1 V, p < 0.05) and BI pacing (1.6 V
vs 1.1 V, p < 0.05). In the patient study, the mean ACT with BIMOS configuration was
again significantly lower compared to UI (3.8 V vs 2.3 V, p < 0.05) or BI pacing (3.5 V
vs 2.3 V, p < 0.05).
Conclusion. Because of a significant reduction in atrial capture
thresholds the novel BIMOS-stimulation concept seems to be superior for atrial floating
pacing. Therefore, BIMOS may be useful for future single-lead DDD pacemaker systems.
|
Key Words
|
|
Pacing
electrode configuration, DDD pacemakers, OA
|
