Doppler echocardiographic description of double-inlet left ventricle in an Arabian horse.

The article presents a unique case of a double-inlet left ventricle, a rare congenital heart defect, in an Arabian horse and highlights the effective use of Doppler echocardiography as a non invasive diagnostic tool in assessing this condition.

Explanation of the Study

• Univentricular atrioventricular (AV) connections are unusual and convoluted birth abnormalities in the heart where both AV valves, which control the flow of blood between the atria and ventricles, connect to a single large chamber. This configuration can consist of left, right, or mixed ventricular morphology.
• While this malformation, specifically a double-inlet ventricle, is well documented in human medicine, there are scant records of it in veterinary literature.
• The study examines an Arabian horse diagnosed with a double-inlet, single ventricle connection of left ventricular type. This denotes that both AV valves lead to a solitary ventricle, in this case of left ventricular morphology.

Additional Findings

• The horse also exhibited a hypoplastic subpulmonary right ventricle, meaning the right ventricle under the pulmonary artery was unusually small or undeveloped.
• Two muscular ventricular septal defects were identified, indicating holes in the muscular part of the septum that divides the ventricles.
• The animal had a stenotic mitral valve, a condition in which the mitral valve that lets blood flow from the left atrium to the left ventricle in the heart is narrowed or constricted.

Role of Doppler Echocardiography

• The use of transthoracic Doppler echocardiography, a noninvasive imaging technique that uses sound waves to capture images of the heart and vessels in real-time, facilitated the diagnosis of these conditions while the horse was still alive.
• This technique also allowed an assessment of the heart’s internal fluid dynamics, revealing how the blood flows and behaves within the heart given the present malformations.
• The study suggests that Doppler echocardiography is a useful tool in the veterinary field for evaluating patients with congenital single ventricle connections, such as a double-inlet left ventricle. Its noninvasive nature paired with its diagnostic effectiveness makes it highly beneficial in these cases.