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Atrial pacing site and atrioventricular conduction in patients paced for sinus node disease
Taichi Watabe1, Haruhiko Abe, Ritsuko Kohno
1Second Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
Insights
Low right atrial septal (LRAS) pacing reduces unnecessary ventricular pacing in sinus node disease (SND) patients. This method shortens the atrioventricular (AV) interval, proving more effective than right atrial appendage (RAA) pacing.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Sinus node disease (SND) necessitates careful pacemaker programming to avoid unnecessary ventricular pacing.
- Minimizing cumulative percent ventricular pacing (cum%VP) is crucial for patients with SND, especially those with coexisting atrioventricular (AV) block.
- Traditional right atrial appendage (RAA) pacing may lead to higher rates of ventricular pacing compared to alternative strategies.
Purpose of the Study:
- To test the hypothesis that low right atrial septal (LRAS) pacing can limit cum%VP in SND patients, with or without first-degree AV block.
- To compare the efficacy of LRAS pacing versus RAA pacing in reducing ventricular pacing burden.
- To evaluate the impact of pacing strategy on the atrioventricular (AV) interval and pacing parameters over one year.
Main Methods:
- A study involving 102 dual-chamber pacemaker recipients diagnosed with SND.
- Measurement of PQ interval and atrial paced to ventricular sensed (Ap-Vs) interval during LRAS and RAA pacing at baseline, 3 months, and 1 year.
- Patients were stratified into two groups based on baseline PQ interval (<200 ms and ≥200 ms) to assess the impact of AV conduction properties.
Main Results:
- LRAS pacing demonstrated a significantly shorter Ap-Vs interval compared to RAA pacing across both patient groups up to 1 year.
- Cumulative percent ventricular pacing (cum%VP) was significantly lower with LRAS pacing (1-7%) compared to RAA pacing (8-48%).
- The beneficial effect of LRAS pacing on reducing cum%VP was consistent regardless of left atrial enlargement.
Conclusions:
- LRAS pacing is superior to RAA pacing in achieving shorter AV intervals in SND patients, including those with first-degree AV block and left atrial enlargement.
- The reduction in AV interval and cum%VP with LRAS pacing is sustained throughout the 1-year follow-up period.
- LRAS pacing represents a valuable strategy for optimizing pacemaker function and minimizing ventricular pacing in SND.
Background:
Unnecessary ventricular pacing in sinus node disease (SND) must be avoided. To test the hypothesis that in SND, with or without 1st degree atrioventricular (AV) block, cumulative percent ventricular pacing (cum%VP) can be limited by low right atrial septal (LRAS) instead of right atrial appendage (RAA) pacing.
Methods:
We studied 102 dual-chamber pacemaker recipients with SND. The PQ interval on 12-lead electrocardiogram and the atrial paced to ventricular sensed interval (Ap-Vs) during LRAS and RAA pacing were measured and compared at implantation, 3 months and 1 year of follow-up. Group 1 included 62 patients with baseline PQ interval <200 milliseconds during LRAS (n = 28) versus RAA (n = 34) pacing. Group 2 included 40 patients with baseline PQ ≥200 milliseconds during LRAS (n = 20) versus RAA (n = 20) pacing. cum%VP were measured at 3 months and 1 year.
Results:
The characteristics and AV conduction properties were similar and the Ap-Vs interval was significantly shorter in the LRAS than in the RAA pacing group up to 1 year (193 ± 32 milliseconds vs. 220 ± 27 milliseconds in Group 1; P = 0.003, 222 ± 41 milliseconds vs. 281 ± 30 milliseconds in Group 2; P < 0.001). While cumulative percent atrial pacing was consistently similar, cum%VP was significantly smaller during LRAS than RAA pacing (1 ± 1% vs. 8 ± 18% in Group 1; P = 0.03, 7 ± 10% vs. 48 ± 38% in Group 2; P < 0.001). Similar observations were made with or without left atrial (LA) enlargement.
Conclusion:
Compared with RAA, LRAS pacing showed shorter AV interval in SND patients with or without 1st degree AV block and LA enlargement. This beneficial effect persisted through 1-year follow-up, and decreased cum%VP significantly.
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