Mitral valvular insufficiency associated with ruptured chordae tendineae in three foals.

The research investigates Mitral valvular insufficiency caused by ruptured chordae tendineae in three foals. The foals exhibited signs of congestive heart failure, which was believed to be due to pulmonary hypertension related to the valvular insufficiency.

Understanding the Condition

• Mitral valvular insufficiency is a cardiac condition where the mitral valve of the heart does not close properly. This disrupted function is related to ruptured chordae tendineae, the tendinous chords that connect the heart’s papillary muscles to the tricuspid valve and the mitral valve in the heart.
• The condition was diagnosed in three foals showing symptoms of congestive heart failure. The heart disease was thought to follow on from the development of pulmonary hypertension, a form of high blood pressure that affects the arteries in the lungs and the right side of the heart.

Observations & Findings

• The septal leaflet of the mitral valve was affected in all three foals. In one case, the foal also had ruptured chordae tendineae associated with the caudal mitral valve leaflet.
• Two foals had further complications beyond Mitral valvular insufficiency. In one foal, bacterial endocarditis, an infection of the heart’s inner lining, was observed alongside the ruptured chordae tendineae. In another, myocardial necrosis, where a portion of the heart muscle dies due to a lack of blood supply, was present.
• For the third foal, the cause of the ruptured chordae tendineae could not be determined and labelled as idiopathic – a term used when the cause of a disease or condition is unknown.

Diagnostic Techniques

• Two-dimensional echocardiography, a test that uses sound waves to create a detailed image of the heart, was conducted on the foals. This test demonstrated a flail mitral valve leaflet in two foals and a ruptured chorda tendineae in one.
• The ruptured chorda tendineae in the third foal could not be visualized with M-mode echocardiography, a simpler form of ultrasound used to assess the structure and motion of the heart.