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Atrial excitability and conduction during rapid atrial pacing
Circulation
|May 1, 1981
Summary
Rapid atrial pacing significantly impacts heart function. High pacing rates increase the energy needed for atrial pacing, slow down electrical signal travel, and alter heart rhythm patterns, affecting atrial excitability and conduction.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- Understanding atrial electrophysiology is crucial for managing cardiac arrhythmias.
- Rapid atrial rhythms can lead to altered cardiac function and potential complications.
Purpose of the Study:
- To investigate the effects of rapid atrial pacing on atrial excitability, conduction, and electrogram morphology in patients undergoing open heart surgery.
Main Methods:
- Utilized temporary atrial wire electrodes for rapid atrial pacing (up to 368 beats/min) in seven post-open heart surgery patients.
- Measured atrial pacing thresholds and conduction times.
- Observed atrial electrogram morphology for alternans.
Main Results:
- Atrial pacing threshold increased exponentially with pacing rate.
- Atrial conduction times were prolonged at rapid pacing rates, both pre- and post-cardiopulmonary bypass.
- A high incidence of atrial electrogram alternans was observed during rapid pacing.
Conclusions:
- Human atrial excitability, conduction, and electrogram morphology are significantly altered during rapid pacing.
- Rapid atrial pacing depresses atrial excitability, prolongs conduction, and induces alternans.
- Findings have implications for understanding and treating rapid atrial rhythms.