Strength duration curve for epicardial left ventricular stimulation
Monique Scally1, Karen J Heston, Andrew G Rudnick
1Temple University Hospital, Philadelphia, Pennsylvania 19140, USA.
Pacing and Clinical Electrophysiology : PACE
|April 28, 2007
Summary
Left ventricular epicardial stimulation chronaxie is similar to right ventricular endocardial stimulation. Optimizing pulse duration through individual chronaxie determination may improve energy efficiency in cardiac resynchronization therapy.
Area of Science:
- Cardiology
- Biomedical Engineering
- Electrophysiology
Background:
- The strength-duration curve for endocardial stimulation is well-documented.
- Limited data exists on left ventricular epicardial stimulation strength-duration curves.
- Left ventricular epicardial parameters are crucial for cardiac resynchronization therapy.
Purpose of the Study:
- To determine the left ventricular epicardial strength-duration curve.
- To compare left ventricular epicardial and right ventricular endocardial stimulation parameters.
- To identify optimal stimulation settings for energy efficiency.
Main Methods:
- Strength-duration curves were constructed for 12 patients with biventricular defibrillators.
- Measurements were taken at subacute (30 days) and chronic (4+ months) post-implant phases.
- Chronaxie was determined for right ventricular endocardial, left ventricular epicardial unipolar, and bipolar stimulation.
Main Results:
- No significant difference was found between right ventricular endocardial and left ventricular epicardial bipolar chronaxie.
- No significant difference was observed between right ventricular endocardial and left ventricular unipolar chronaxie.
- Most determined chronaxie values were lower than default device settings.
Conclusions:
- Left ventricular epicardial chronaxie is comparable to right ventricular endocardial chronaxie.
- Current default pulse durations exceed optimal settings for many patients.
- Individual chronaxie assessment can lead to significant energy savings in device therapy.
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