ISSN:
1540-8159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
If atrial sensing ability of a single-lead VDD pacemaker is well accepted at rest, the detection quality by atrial floating electrodes remains less recognized during exercise. The aim of this study was to verify, during tread-mill test and a continous telemetry, the atrial tracking performance using four different leads technologies. From November 1994 to July 1997, 21 patients (71.3 ± 6.3 years old. 7 female, cardiopathy: 57%) were paced for isolated high degree (permanent: 13, paroxystic: 8) AV block. The implanted devices were the Vitatron Saphir/Brillant lead (13 patients), Intermedics Unity/425/04–13 lead (5 patients), Pacesetter Addvent (2 patients), and Biotronik Eikos (1 patient). The acute atrial signal amplitude was 1.66 ± 0.75 mV. The treadmill test used the chronotropic assessment exercise protocol after pacemaker reprogramming to detect atrial undersensing (AV delay ≤ 120 ms, no hysteresis, no flywheel, upper rate increase). The mean delay was 31.1 weeks (range 1–100). The testing duration was 6.1 ± 2.3 minutes, the number of steps was 3.3 ± 1.3 per patient, and the peak exercise rate was 135 ± 19 beats/min. At rest, complete atrial tracking was complete in 90% of the patients, and during testing in only 23.8% of the patients, while AV synchronization 〉 95% was present in 57.1%, 〉 90% in 71.4%, and 〉 85% in 90.4% of patients (Vitatron 13/13, Intermedics 3/5, Biotronik 1/1, and Pacesetter 1/2). During the recovery period synchronization was always 〉 95%. The mean P wave amplitude at rest was 1.1 ± 0.5 mV; during the first step, 1.04 ± 0.61 mV; second step, 0.94 ± 0.53 mV; third step, 0.82 ± 0.58 mV; fourth step, 0.67 ± 0.39 mV; and during recovery, 1.13 ± 0.67 mV. The mean P wave decrease signal at peak of exercise is 0.21 mV (from -1.31 to +0.5). In fact, P wave variations have several patterns: a decrease was measured in 7 patients, an increase in 2 patients, and no significant change in 7 patients. Single-lead VDD P wave identification during exercise was almost accurate. However, often there was progressive lowering of atrial sensing with transient loss of AV synchrony.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1540-8159.1999.tb00406.x
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