Types of Bicuspid Aortic Valve
How Many Cusps?
Can You Classify This Valve?
A bicuspid aortic valve (BAV) is the most common congenital heart defect and affects about 2% of the population worldwide. Echocardiography is the preferred non-invasive imaging tool for early diagnosis and surveillance of this valvulopathy. Proper technique and accurate classification can improve echo reporting and patient outcomes.
Do you know how to classify this type of bicuspid aortic valve (BAV) based on the short axis transthoracic image above? In this lesson, we will discuss the classification of BAVs with the help of 6 case examples.
History
The earliest documented interest in the aortic valvular complex dates back to the Renaissance era, when an artist by the name of Leonardo da Vinci took a liking to the cardiovascular system. He studied animal and human specimens to better understand the mechanics of the heart and fluidic behavior; he concluded that the heart fed itself with the help of the aorta, coronary arteries, and bronchi.
Da Vinci’s interest in hydraulic engineering led to valve experimentation in the early 1500’s; Leonardo observed that blood would flow from the atria into the ventricles and valve failure would result in retrograde flow, or regurgitation. These studies served as a foundation for subsequent cardiology scholars and researchers as they learned about the aortic valve morphology.
Anatomy
The aortic valve is located at the aortic root and separates the left ventricular chamber from the aorta. It it comprised of a fibrous ring and three leaflets: the left coronary cusp, the right coronary cusp, and the non-coronary cusp. Traditionally, the left main coronary artery (LMCA) and the right coronary artery (RCA) originate at the aortic sinus just proximal to the aortic valve.
The semilunar valves do not need papillary muscles or chordae tendineae to function because the attachment to the arterial wall provides them with stability. As pressure builds in the ventricle during systole, the valve will open and blood is ejected. Blood will pool in the aortic sinus and allows it to enter the LMCA and RCA, delivering oxygen-rich blood to the heart.
Bicuspid Aortic Valve
The bicuspid aortic valve is the most common congenital valvular abnormality that affects about 2% of the general population. Leaflet fusion and impaired functionality can lead to congestive heart failure, aortic regurgitation, or aortic stenosis. According to the Cleveland Clinic, about 80% of patients with a BAV will need aortic valve surgery. Many of these patients will present with an additional aortopathies, such as aortic aneurysms or in some cases coarctation of the aorta (Cleveland Clinic, 2024).
The parasternal long-axis may display systolic “doming” which indicates commissural fusion and reduced aortic valve area. Observe the right coronary and non-coronary cusp in the above transthoracic clip. An eccentric diastolic closure line may also be seen in the parasternal view and is best appreciated with m-mode imaging. Some hospitals have removed m-mode from standard protocol but it can be especially helpful in cases of BAV, aortic stenosis, mitral valve prolapse, and mitral stenosis (Frontiers, 2024).