Related Experiment Videos
An engineering model of dynamic cardiomyoplasty. I
F Y Chen1, D B Lautz, B J deGuzman
1Division of Engineering and Applied Sciences, Harvard Graduate School of the Arts and Sciences, Cambridge, MA, USA.
Annals of Biomedical Engineering
|May 7, 1998
Summary
Dynamic cardiomyoplasty (DCM) uses skeletal muscle to assist the heart. An engineering model shows that increasing latissimus dorsi (LD) muscle strength post-training is key to improving cardiac stroke volume.
Area of Science:
- Biomedical Engineering
- Cardiovascular Surgery
- Skeletal Muscle Physiology
Background:
- Dynamic cardiomyoplasty (DCM) is a surgical heart failure treatment using latissimus dorsi (LD) muscle.
- A 6-week training protocol enhances LD muscle for chronic stimulation.
- Clinical trials show symptomatic and modest hemodynamic improvements, but the mechanism is debated.
Purpose of the Study:
- To test if DCM augments cardiac stroke volume by improving systolic function.
- To formulate an engineering model of DCM to predict stroke volume.
- To investigate the role of LD muscle properties in DCM efficacy.
Main Methods:
- Developed a nested elastance chamber model for the heart and LD muscle.
- Represented vasculature using a two-element Windkessel model.
- Validated model predictions against measured stroke volumes in five goats.
Main Results:
- Model accurately predicted stroke volume for both stimulator ON and OFF beats (r=0.87 and r=0.91).
- Untrained LD muscle provided only moderate increases in stroke volume.
- Model confirmed the importance of LD muscle conditioning.
Conclusions:
- DCM's mechanism involves augmenting systolic function.
- Future research should prioritize enhancing LD muscle strength post-training for greater stroke volume augmentation.
- Optimizing skeletal muscle conditioning is crucial for DCM effectiveness.