Functional Anatomy of the Sheep Heart as a Model for Testing Cardiovascular Devices

Area of Science:

• Cardiovascular Research
• Comparative Anatomy
• Biomedical Engineering

Background:

• The ovine heart is increasingly utilized as a preclinical model for cardiovascular devices.
• Understanding its anatomical and functional characteristics relative to humans is crucial for effective device testing.

Purpose of the Study:

• To evaluate the ovine heart as an animal model for preclinical testing of implantable cardiovascular devices.
• To compare numerical anatomical and functional characteristics of the ovine heart with those of the human heart.

Main Methods:

• Echocardiography was performed on 17 Romanov sheep (two weight groups).
• Measurements included ventricular dimensions, wall thickness, and aortic root/valve parameters.
• Post-mortem analysis provided direct measurements of aortic and pulmonary artery dimensions.

Main Results:

• Ovine heart ejection fraction, myocardium thickness, and major vessel diameters are comparable to humans.
• Ovine left ventricular volumes (LV EDV, LV ESV) are significantly smaller than human values.
• Differences exist in aortic root height, intercommissural distances, and cusp arrangement compared to humans.

Conclusions:

• The ovine heart presents a valid model for preclinical cardiovascular device testing.
• Successful application requires careful animal screening via echocardiography and appropriate device sizing.
• While similar, ovine and human cardiac anatomy are not identical, necessitating consideration of species-specific differences.