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Optimizing sequential biventricular pacing using radionuclide ventriculography
Haran Burri1, Henri Sunthorn, Aernout Somsen
1Cardiology Service, Geneva University Hospitals, Geneva, Switzerland. haran.burri@hcuge.ch
Heart Rhythm
|September 21, 2005
Summary
Optimizing biventricular pacemaker settings by adjusting interventricular delays can significantly improve left ventricular ejection fraction (LVEF). Individual patient assessment is crucial for maximizing resynchronization therapy benefits.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Devices
Background:
- Biventricular pacemakers are standard for heart failure, typically using synchronous pacing.
- The impact of sequential pacing and specific interventricular (VV) intervals on cardiac function is not well-defined.
Purpose of the Study:
- To determine if sequential biventricular pacing improves left ventricular ejection fraction (LVEF) and reduces cardiac dyssynchrony.
- To evaluate nuclear ventriculography as a method for optimizing pacemaker settings.
Main Methods:
- Studied 27 heart failure patients with biventricular devices.
- Measured LVEF and dyssynchrony using radionuclide ventriculography across various VV intervals.
- Analyzed interventricular and intraventricular dyssynchrony using phase analysis.
Main Results:
- Significant LVEF changes (up to 10%) occurred in 89% of patients with different VV intervals.
- Optimized sequential pacing increased LVEF by 18% in most patients, while 33% achieved maximum LVEF with simultaneous pacing.
- Interventricular dyssynchrony was minimized at an LV-20 ms delay (P = .024), with no significant change in intraventricular dyssynchrony.
Conclusions:
- VV interval programming significantly impacts LVEF, demonstrating considerable patient-specific variability.
- Individualized programming is essential for optimizing biventricular pacemaker therapy and resynchronization.