Introduction
Certain cardiac malformations develop by birth, where the person acquires defects due to errors in the developmental process during the intrauterine period (within the womb). Though such defects are present right from birth, many of those defects remain silent without eliciting any manifestations in the early phase of life. Obvious manifestations will often get reflected in the later stages of life. The quadricuspid aortic valve is one such condition, with a meager incidence rate. It is often detected in close association with other heart-related abnormalities and anomalies.
What Is an Aortic Valve?
The human heart has four distinct valves that separate each of the chambers present within the heart. Valves are separations that act like one-way doors. It ensures that the blood flow occurs only in the specific intended direction. The upper compartments of the heart are medically coined as atria, while the lower ones are called ventricles. There are two atria and two ventricles, one on either side of the heart.
Atria and ventricles are set apart with the help of valves. Similarly, the ventricles are bridged with blood vessels with the help of specific valves called semilunar valves. As the name suggests, its shape resembles that of a crescent moon. Aortic valves come under the semilunar valves, acting as an interface between the aorta (blood vessel) and left ventricle.
Aortic valves check the rearward flow of blood from the artery back to the ventricle and facilitate the flow of blood from the ventricle on the left side to the aortic vessel during ventricular contraction (the left ventricle compresses on itself, pushing the blood into the aorta). Each aortic valve is structured in three united leaflets, also known as a tricuspid valve. These leaflets are more or less of the same dimension and are symmetrical. Deviation in the structure and number of leaflets in the valve can significantly impact the functions of the aortic valve and reflect in the form of cardiac anomalies.
What Is a Quadricuspid Aortic Valve?
The quadricuspid aortic valve is an inborn valvular anomaly or disparity where the individual possesses four leaflets on the aortic valve instead of three. In addition, the leaflets also elicit changes in size and shape, which pose challenges to the functions of the aortic valve. The asymmetric cusps in the quadricuspid aortic valve (QAV) impair the patency in the flow of blood during ventricular contraction. Studies have revealed that around 18 to 32 percent of individuals with QAV have other associated inborn cardiac irregularities and malformations. QAV is reported to have a slight preference for males over females.
What Are the Signs and Symptoms of a Quadricuspid Aortic Valve?
The quadricuspid aortic valve often remains latent without reflecting any obvious manifestations in the early ages. Clinical manifestations become apparent and evident, especially after 50 years of age. However, the condition may sometimes be detected accidentally during radiographic or surgical procedures. Some of the frequently encountered symptoms of the quadricuspid aortic valve include the following:
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Dyspnea: The person experiences trouble breathing, and breaths become considerably short and shallow.
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Angina: The person may encounter occasional pain in the chest region.
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Palpitation: There will be a pronounced rise in the heart beating rate. The heart tends to beat at a higher pace than normal.
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Pedal Edema: There will be considerable ballooning of the legs and feet. Pedal edema develops due to the piling up of fluid in the lower extremity areas, which gets reflected as swollen legs.
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Fatigue and Syncope: The person often experiences worn-out feelings and blackouts. The patients report trouble doing activities involving physical exertion.
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Congestive Heart Failure: If the person ignores the warning signs and symptoms, it may progress into congestive heart failure, with a remarkable collapse in cardiac functions like compromised blood pumping.
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Aortic Regurgitation: It is the most widely reported manifestation in QAV. The lack of symmetry and aberrant number of cusps in the aortic valve makes it difficult to seal off the reverse blood flow into the ventricle from the aorta. This reverse blood flow is technically denoted as aortic regurgitation.
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Aortic Stenosis: Aortic stenosis is encountered during the later stages of QAV, where the arterial lumen shrinks, restricting the flow of blood through it.
What Causes the Development of the Quadricuspid Aortic Valve?
The exact cause of aberrant development of the aortic valve is unknown to date. Discussions and research are going on over the topic. Irregularities or disturbances in the formation and division of aortic valvular tissues in the early stage (within the womb) give rise to anomalous development of the aortic valve.
How Is the Quadricuspid Aortic Valve Diagnosed?
The quadricuspid aortic valve is often detected and figured out at later ages once patients start flagging apparent manifestations. Earlier quadricuspid aortic valves were detected by chance during open heart surgeries. The percentage of quadricuspid aortic valve detection has rocketed with advancements in technology.
Echocardiography holds the upper hand in diagnosing QAV. It aids in detecting aortic valvular discrepancies by better picturing the size, shape, and number of leaflets in the aortic valve. Echocardiography utilizes sound waves for imaging the heart and heart valves.
In addition, computed tomography angiograms (CTA) and cardiac magnetic resonance imaging (CMR) also illuminate the QAV diagnosis. Cardiac magnetic resonance imaging also gives an idea about the extent of regurgitation. CTA employs X-rays, while CMR depicts the images of the heart with the help of radio waves and magnetic fields.
How Is the Quadricuspid Aortic Valve Managed?
The treatment strategies for correcting the quadricuspid aortic valve are mainly surgical and exploratory. Not all QAV patients are advised for surgical correction. Hence, the surgical intervention is made only after considering the functional impairments, the extent of regurgitation, and stenosis precipitated by the malformed aortic valve.
Aortic valve replacement is the surgical intervention of choice for QAV patients with a remarkable valvular function collapse and awful aortic regurgitation. In aortic valve replacement surgeries, the malformed and impaired valves are substituted with artificially made valves to simulate the functions of healthy valves.
Conclusion
The quadricuspid aortic valve is a peculiar valvular abnormality that develops by birth. The aberration in the standard structure and shape of the cusps poses trouble in valvular functions like maintaining blood flow in a single direction. Compromised closure of the valve imparted by defective structure paves the way for cardiac complications such as aortic regurgitation and heart failure. Prompt attention to the manifestations often aids in figuring out the condition early, which helps tackle the progression. Valve replacement is reported to be a successful treatment strategy for QAV, which can extend the life expectancy of the patients.
