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Comparison of intrinsic versus paced ventricular function.
1Section of Cardiology, Loma Linda University Medical Center, California 92354.
Pacing and Clinical Electrophysiology : PACE
|November 1, 1992
Summary
Optimizing atrioventricular (AV) delay in cardiac pacing significantly improves hemodynamic performance. AV sequential pacing with optimal AV delay offers superior cardiac output and stroke volume compared to atrial pacing in patients with prolonged native AV conduction.
Area of Science:
- Cardiology
- Biomedical Engineering
- Electrophysiology
Background:
- Evidence supports optimizing atrioventricular (AV) delay in cardiac pacing.
- Controversy exists regarding the value of intrinsic versus paced ventricular activation.
Purpose of the Study:
- To compare various AV delays at rest in patients with native AV delays >= 200 msec.
- To evaluate hemodynamic performance with AV sequential pacing versus atrial pacing.
Main Methods:
- Nine patients with DDD pacemakers, intact AV conduction, and normal ventricular activation were studied.
- Ten studies were performed in AAI and DDD modes at paced heart rates of 60/min or intrinsic rate.
- Stroke volume (SV) and cardiac output (CO) were measured.
Main Results:
- Optimal AV delay in DDD mode averaged 157 msec (range 125-175 msec).
- DDD mode with optimal AV delay showed an 11% improvement in CO and 9% in SV compared to AAI pacing.
- Patients with intrinsic AV conduction > 220 msec had a significant 13% CO and 11% SV improvement with DDD pacing.
Conclusions:
- Optimal AV delay is crucial for hemodynamic performance in cardiac pacing.
- AV sequential pacing with optimal AV delay may outperform atrial pacing in patients with prolonged native AV conduction (> 220 msec).