Comparative analysis of ventricular stiffness across species

Area of Science:

• Cardiovascular Physiology
• Comparative Anatomy
• Biomedical Engineering

Background:

• Ventricular diastolic properties are key to cardiac function and cardiovascular disease.
• Assessing ventricular stiffness using end-diastolic pressure-volume relationship (EDPVR) is challenging across varying chamber volumes.
• Accurate comparison of ventricular stiffness across species with different cardiac sizes remains a significant hurdle.

Purpose of the Study:

• To introduce a novel method for comparing ventricular stiffness across diverse animal models.
• To establish a relative ventricular stiffness index using normalized end-diastolic pressure-volume relationship (EDPVR) data.
• To analyze and rank ventricular stiffness in various species, including non-model organisms.

Main Methods:

• Applied an exponential approximation formula to EDPVR data, normalizing ventricular volume by ventricular weight.
• Utilized ex vivo ventricular pressure-volume analysis data from Wistar rats, red-eared slider turtles, masu salmon, and cherry salmon.
• Reviewed the utility and limitations of normalized EDPVR analysis in comparative studies.

Main Results:

• Successfully measured and ranked ventricular stiffness in chambers of varying sizes and shapes.
• Demonstrated the feasibility of comparing ventricular stiffness across homologous and heterologous species.
• Provided insights into the mechanical factors influencing ventricular stiffness, such as viscoelastic components and sarcomere length.

Conclusions:

• Normalized EDPVR analysis offers a robust method for comparing ventricular stiffness across diverse species.
• This approach enhances our understanding of cardiac diastolic function and its evolutionary adaptations.
• The findings facilitate comparative studies of cardiovascular health and disease in a broader range of organisms.