Global cardiac function: mechano-energetico-informatics

Area of Science:

• Cardiovascular Physiology
• Cardiac Mechanics
• Bioenergetics

Background:

• Understanding global cardiac function requires integrating mechanics, energetics, and informatics.
• Previous research established end-systolic maximum elastance (Emax) as a key index of ventricular contractility.

Purpose of the Study:

• To review the development and application of Emax and pressure-volume area (PVA) for assessing cardiac function.
• To explore the relationship between Emax, PVA, and oxygen consumption (V(O(2))) in various cardiac conditions.
• To investigate the cross-bridge behavior basis of Emax and develop integrative analyses for excitation-contraction coupling.

Main Methods:

• Utilized canine hearts to establish Emax as a measure of ventricular contractility.
• Expanded Emax to PVA to quantify total mechanical energy during ventricular contraction.
• Analyzed the relationship between Emax, PVA, and V(O(2)) in different pathophysiological states.
• Examined X-ray diffraction of papillary muscle to understand Emax at the cross-bridge level.
• Developed an integrative analysis using Emax-PVA-V(O(2)) to estimate calcium recruitment in excitation-contraction coupling.

Main Results:

• Emax was validated as a reliable index of ventricular contractility.
• PVA emerged as a robust measure of total mechanical energy, correlating with ventricular energetics and V(O(2)).
• Emax was found to modulate the V(O(2))-PVA relationship, with varying dependencies in different heart conditions.
• Insights into the cross-bridge mechanisms underlying Emax were gained.
• A novel integrative analysis was established to quantify calcium dynamics during cardiac contraction.

Conclusions:

• The developed mechano-energetico-informatic approaches provide a comprehensive framework for understanding cardiac function.
• These methods are crucial for advancing cardiac physiology in the post-genomic era, requiring integrated physiomic knowledge.
• The findings facilitate a deeper understanding of cardiac energetics and excitation-contraction coupling.