Aortic stenosis . It is a disease that refers to the pathological, pathophysiological and clinical changes that are associated with the decrease in the aortic valve area. Its etiology is varied, the most frequent being those of congenital origin, those secondary to rheumatic disease and calcified stenosis in the elderly.
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- 1 Causes
- 2 Symptoms
- 1 Most characteristic symptoms
- 3 Diagnosis
- 4 Treatment
- 5 Prevention
- 6 External links
- 7 Sources
As the aortic valve narrows further, the pressure increases within the left ventricle of the heart . This makes the ventricle thicker, which decreases blood flow and can lead to chest pain. As the pressure continues to increase, the blood may be dammed up in the lungs and breathing may be difficult. Severe forms of aortic stenosis prevent enough blood from reaching the brain and the rest of the body, resulting in dizziness and fainting.
Aortic stenosis can be present from birth (congenital) or can develop later in life (acquired). Children with aortic stenosis may have other congenital conditions.
In adults, aortic stenosis occurs most often in those who have had rheumatic fever , a condition that can develop after a tonsillitis Streptococcal or scarlet fever . Valve problems do not develop for 5 to 10 years or more after rheumatic fever occurs. This fever is increasingly rare in the United States .
Among adult patients, the appearance of the first symptoms usually occurs after the age of 50, when the valve orifice has been reduced to less than 0.6-0.7 cm 2 .
Most characteristic symptoms
- Angina , as a manifestation of the imbalance between myocardial hypertrophy and coronary irrigation. In a percentage of these patients (20-30%) it is shown that there is an added coronary disease.
- Dyspnea on exertion, due to elevated AI pressure, secondary to diastolic hypertension of the left ventricle, due to decreased compliance and deterioration of the contractile capacity of the myocardium . In extreme cases, pulmonary hypertension and global heart failure can be established.
- Stress syncope , expression of the mismatch between the decrease in vascular resistance that accompanies exercise and the difficulty of the ventricle to instantly increase expenditure.
- Some patients with significant aortic stenosis may experience sudden death, which could be due to marked hypotension and ventricular arrhythmias .
The diagnosis of aortic stenosis can be raised against different findings or circumstances:
It may be due to a history of syncope or angina, or due to physical examination findings, even in asymptomatic patients. It is usually suspected in the presence of left ventricular hypertrophy on the ECG or due to the appearance of heart failure without obvious cause in the elderly.
For the diagnosis and determination of the magnitude of the stenosis, the following Laboratory tests are useful:
- Electrocardiogram : in patients with significant aortic stenosis, the presence of “systolic overload” type ventricular hypertrophy is common. However, LVH may be hidden by the presence, also frequent, of Left Branch Block.
- Chest x – ray : Because concentric hypertrophy causes little dilation of the cavities, the x-ray may show little alteration of the cardiac image, dilation of the aortic root, and slight signs of left ventricular growth. A sign of utility is the presence of aortic valve calcifications on fluoroscopy.
- Echocardiogram : it is very useful. It allows to appreciate the degree of ventricular hypertrophy and the presence of thickening and calcification of the aortic veils. The valve gradient can be calculated using a dopler , with a very good correlation with the hemodynamic study. It allows to differentiate valve stenosis from other forms of obstruction, such as sub or supra aortic stenosis and cardiomyopathy.
- Hemodynamic and angiographic study: although the calculation of the severity of the stenosis can be done with non-invasive methods, when angina exists, the only way to know the involvement of the coronary arteries is through angiography .
The treatment of patients with aortic stenosis, regardless of its degree of severity, should include prevention of infective endocarditis , eventually of Rheumatic Fever and periodic controls to monitor the degree of repercussion on the left ventricle.
In patients with asymptomatic significant stenosis (mean gradient> 40 mmHg.), Physical efforts should be limited, particularly those of the isometric type, and a control program should be established every 6 to 12 months. In patients with significant symptomatic aortic stenosis, valve replacement surgery is indicated .
In some symptomatic patients, surgery may be considered when the transvalvular gradient is very important (mean gradient> 64 mmHg), particularly if the patient does not want to comply with the limitations of physical activity or has limitations to perform periodic medical controls.
Surgical indication is complex when there is myocardial involvement and decreased cardiac output. In these cases it is difficult to assess the anatomical magnitude of the stenosis and it is not easy to anticipate the recovery of post-operative ventricular function either.
Aortic valvuloplasty is an option in children. Occasionally, Balloon Valvuloplasty may be considered in adults, as a palliative measure in patients with advanced heart failure.
Treat streptococcal infections promptly to prevent rheumatic fever, which can cause aortic stenosis. This condition itself is often not preventable, but some of its complications are