Hand-held, dynamic indentation system for measuring myocardial transverse stiffness

Area of Science:

• Cardiovascular Research
• Biomedical Engineering
• Medical Device Development

Background:

• Myocardial abnormalities and altered regional loading are key factors in heart disease progression, including infarct expansion, remodeling, cardiomyopathy, and arrhythmias.
• Accurate estimation of regional wall stress is crucial for distinguishing between primary muscle and loading abnormalities in the heart.
• Previous methods using geometric models and finite element analysis for wall stress estimation lacked validation.

Purpose of the Study:

• To develop and validate a novel hand-held dynamic indentation system for measuring regional myocardial wall stress.
• To enable rapid and accurate assessment of transverse stiffness, a surrogate for myocardial wall stress, in intact hearts.

Main Methods:

• A hand-held dynamic indentation system was designed to measure the transverse stiffness of cardiac muscle.
• The system was validated using finite-element analysis and direct measurements on isolated heart muscle and non-biologic materials.
• The device can perform multiple estimations of wall stress within a single cardiac contraction cycle (15 milliseconds).

Main Results:

• The dynamic indentation system accurately estimates myocardial wall stress.
• Validation confirmed the system's reliability across various materials and conditions.
• The system allows for real-time, regional assessment of cardiac mechanical properties.

Conclusions:

• The validated dynamic indentation system provides an accurate method for estimating regional myocardial wall stress.
• This technology can significantly improve the understanding of cardiac pathophysiology and guide therapeutic interventions.
• The sensor has potential applications in surgical planning for cardiac procedures and advancing cardiovascular research.