This valvular malformation is due to an error in fetal development, which occurs during the first weeks of pregnancy; in many cases, the defect in question is the result of a hereditary mutation.
The bicuspid aortic valve can have several consequences: in some patients, it does not cause problems throughout life; in others, it causes heart complications from a young age; in still others (80%, the majority), it is responsible for heart complications around the age of 30-40.
The bicuspid aortic valve needs treatment when it has resulted in complications; in these situations, the therapy consists of a cardiac surgery aimed at replacing or repairing the aortic valve.
congenital, where by valvulopathies s "we mean the anomalies and malformations of the heart valves.
Other congenital valvular diseases are monocusp aortic valve, quadricuspid aortic valve, congenital mitral stenosis and congenital pulmonary valve stenosis.
Anatomy of the Aortic Valve: A Brief Review
The aortic valve is one of the four valves responsible for regulating the flow of blood within the heart.
It is located in the left ventricle, at the point where it connects to the aorta, and is responsible for controlling the passage of blood between these two compartments, preventing its reflux (ie its return back).
The aortic valve is an example of a tricuspid semilunar valve; "tricuspid" means that three flaps of connective tissue, also called cusps (due to their pointed shape), regulate the opening and closing of this valve.
Like all other heart valves, the aortic valve, when functioning properly, does not allow for the retrograde flow of blood (in other words, for the blood to flow back).
For further information: Aortic Valve: Anatomy and Function
Epidemiology: How common is Bicuspid Aortic Valve?
According to the most reliable epidemiological estimates, bicuspid aortic valve is a cardiac malformation found in 1-2% of the general population.
For reasons still unclear, it is the males who suffer most; the male-female ratio is 2: 1 in favor of the former.
Finally, it is interesting to point out that the bicuspid aortic valve is the congenital heart defect and, obviously, also the most common and widespread congenital valve disease in the general population.
of the unborn child.What causes such failure of fetal development is not always entirely clear.
Studies in this regard, however, suggest that, in a good number of cases, the bicuspid aortic valve is a malformation with a hereditary component, ie transmitted by parental route; these same studies also revealed the implication of the NOTCH1 gene and an autosomal dominant trait with incomplete penetrance by the condition in question.
Bicuspid Aortic Valve: Pathophysiology
Initially, the anatomical anomaly that characterizes the bicuspid aortic valve does not prevent the aortic valve from performing its functions; in the first period of life, in fact, the aortic valve opens and closes, allowing the right amount of blood to flow into aorta without any particular problems.
With the passage of time, however, there tends to occur a progressive wear of the valve flaps associated with the accumulation of calcium deposits on them, which, first, leads to their reduced mobility and, subsequently, to the narrowing of the valve orifice (stenosis aortic) and / or in a no longer hermetic closure of the aortic valve itself (aortic insufficiency); this wear of the flaps and the accumulation on them of calcium deposits are most likely due to the greater turbulence that the blood flow undergoes when it crosses a bicuspid aortic valve rather than a tricuspid one.
In most cases, the bicuspid aortic valve shows the first signs of wear when the patient reaches adulthood; therefore, in the period of childhood, the valve anomaly is not responsible for particular problems and the aortic valve functions correct.
Bicuspid Aortic Valve: Risk Factors
At present, the only certain risk factor for bicuspid aortic valve is the presence, in the family, of relatives carrying this cardiac anomaly.
, for the reasons mentioned above: for several decades, although it has two cusps instead of three, the aortic valve is able to perform its functions correctly.However, when the valve flaps begin to wear out and accumulate calcium deposits, the condition begins to produce the first problems, the result of the onset of the first complications.
It should be noted that there are borderline cases, in which the anomaly characterizing the bicuspid aortic valve does not cause any type of problem for life or in which it is so severe that the aortic valve functions incorrectly already in the first years of life and the patient develops congestive heart failure from an early age.
It is equally important to point out that, in many cases, already at a young age, the bicuspid aortic valve manifests itself with a heart murmur, detectable by examination with a phonendoscope.
Bicuspid Aortic Valve: Complications
When the valve cusps stiffen due to wear and calcium deposits, the aortic valve begins to shrink and / or no longer close tightly.
Narrowing of the aortic valve is called aortic stenosis, while its failure to seal is a condition known as aortic regurgitation (or aortic regurgitation).
Aortic stenosis
Aortic stenosis is a valve disease characterized by narrowing of the aortic valve orifice.
This condition clearly affects the passage of blood from the left ventricle to the aorta and triggers a process known as left ventricular hypertrophy, the peculiarity of which is the thickening of the left ventricular wall (hypertrophy) and its weakening.
Aortic stenosis is characterized by symptoms, such as:
- Chest pain (angina pectoris)
- Dyspnea on exertion;
- Feeling faint or syncope
- Palpitations;
- Sense of fatigue and tiredness;
- Heart murmur.
In the absence of adequate treatments and in its most advanced stages, aortic stenosis can lead to serious complications, including:
- Heart failure;
- Embolism;
- Endocarditis;
- Arrhythmias;
- Pathologies of the mitral valve;
- Sudden cardiac death.
Treatment of aortic stenosis includes, in milder cases, periodic monitoring of the condition and, in moderate and severe cases, surgery to replace or repair the defective aortic valve.
Causes of Aortic Stenosis
The bicuspid aortic valve is not the only cause of aortic stenosis; the narrowing of the aortic valve, in fact, can also be a consequence of advancing age (senile aortic calcification) or conditions such as rheumatic fever, endocarditis or systemic lupus erythematosus.
For further information: Aortic Stenosis: What it is, Causes and Symptoms
Aortic insufficiency
Aortic insufficiency is valvulopathy characterized by the lack of hermetic closure of the aortic valve and the consequent reflux of blood from the aorta to the left ventricle.
The presence of aortic insufficiency reduces, more or less significantly, the left ventricular ejection fraction, ie the amount of blood introduced into the aorta by the left ventricle.
This triggers a pathophysiological mechanism such that the heart, striving to counteract the reduction of the left ventricular ejection fraction, becomes, over time, hypertrophic in the left ventricle and weakens.
Sometimes associated with aortic stenosis, aortic insufficiency is typically responsible for symptoms such as:
- Chest pain (angina pectoris)
- Dyspnea on exertion;
- Presyncope or syncope;
- Edema in the lower limbs;
- Palpitations;
- Weakness and ease of fatigue;
- Heart murmur.
In the absence of appropriate treatment and in its most advanced stages, aortic insufficiency can lead to serious complications, including:
- Heart failure;
- Endocarditis;
- Arrhythmias of various kinds;
- Sudden cardiac death.
Treatment of aortic insufficiency includes, in milder cases, periodic monitoring of the condition and, in moderate and severe cases, surgery to replace or repair the defective aortic valve.
The bicuspid aortic valve is not the only cause of aortic insufficiency; the lack of hermetic closure of the aortic valve, in fact, can also be a consequence of advancing age (senile aortic calcification), a trauma to the chest or conditions such as rheumatic fever, endocarditis, hypertension or systemic lupus erythematosus.
For further information: Aortic Insufficiency: What it is, Causes and SymptomsBicuspid Aortic Valve: Associated Diseases
In a non-negligible number of cases, the bicuspid aortic valve is associated with coarctation of the aorta, a condition characterized by abnormal narrowing of the initial part of the aorta (it is the part of the aorta that emerges from the left ventricle of the heart and is in connection with the aortic valve).
.In general, the diagnostic process leading to the identification of the bicuspid aortic valve begins with the physical examination and the medical history; after which, it continues with an "echocardiography and, finally, it ends with an magnetic resonance.
It may happen, however, that the diagnostician makes use of other investigations, in order to deepen the information obtained up to that moment; for example, he may order an EKG, CT scan, chest x-ray, and / or a procedure known as cardiac catheterization.
Importance of the Physical Exam
During the physical examination for the diagnosis of bicuspid aortic valve, auscultation of the heart has a "fundamental importance: as readers will remember, in fact, the bicuspid aortic valve is characterized, very often, already from the young age of the patient, by the presence of a heart murmur.
Other Exams: the purpose
In-depth investigations (eg: electrocardiogram, cardiac catheterization, etc.) are used to investigate the health conditions of the heart and to identify any other cardiac pathologies associated with the bicuspid aortic valve.
, ACE inhibitors, calcium channel blockers and angiotensin II receptor antagonists.
Surgical therapy for bicuspid aortic valve complications includes at least three intervention techniques:
- Replacement of the aortic valve. As the name suggests, this procedure consists of removing the defective original aortic valve and replacing it with a new, artificial (very durable, but with different adverse effects) or biological (less durable, but safer for the patient) valve.
Aortic valve replacement is an "operation that can be performed either through thoracotomy or, alternatively, through less invasive surgical approaches (minithoracotomy or transcatheter modality) - Repair of the aortic valve. This surgery involves the remodeling of the aortic valve, in order to restore its original functions.
Generally, cardiac surgeons prefer to perform the repair procedure using thoracotomy, therefore through a very invasive approach; however, it is necessary to point out the possibility of practicing less invasive methods (minithoracotomy or transcatheter modality).
Aortic valve repair is a very beneficial option, but unfortunately it is not always possible. - Balloon catheter valvuloplasty. This operation consists in widening the valve orifice by passing a catheter through the aortic valve.
Valvuloplasty with balloon catheter has temporary effects and is indicated in patients of young or very young age, who cannot yet undergo invasive procedures as much as the previous ones.
Bicuspid Aortic Valve and Drugs
