Left ventricular changes resulting from chronic aortic regurgitation in dogs

Area of Science:

• Cardiovascular Research
• Animal Models
• Cardiac Physiology

Background:

• Chronic aortic regurgitation (AR) can lead to significant cardiac remodeling.
• Understanding the long-term effects of AR on cardiac function is crucial.
• Non-invasive methods for inducing AR are needed to study its natural progression.

Purpose of the Study:

• To establish a closed-chest puppy model of chronic aortic regurgitation (AR).
• To assess the impact of induced AR on puppy growth and development.
• To characterize the resulting left ventricular (LV) dilation and hypertrophy.

Main Methods:

• Chronic AR was induced in 7 closed-chest puppies via aortic valve perforation using catheterization.
• Puppy growth and cardiac parameters were monitored for approximately 2 years.
• Left ventricular (LV) end-diastolic volume and mass were compared to littermate controls.

Main Results:

• Induced AR did not interfere with normal growth and development in puppies.
• A gradual increase in left ventricular (LV) dilation (116%) and hypertrophy (114%) was observed in puppies with AR.
• The catheterization technique allowed for studying AR effects without thoracotomy or pericardiotomy.

Conclusions:

• Catheter-induced chronic aortic regurgitation (AR) in puppies provides a viable model for studying cardiac remodeling.
• This model allows for the investigation of left ventricular (LV) dilation and hypertrophy progression.
• The technique avoids confounding factors associated with open-chest procedures, facilitating research into AR pathophysiology.