Aortic Contracting

The aortic contracting , also called sténose aortic , is a cardiac disease which consists of a deterioration of the aortic valve which is narrowed.

It is about the one of the cardiac valvulopathies. It is generally of degenerative origin (ageing and calcifications of the valve). Its mechanism is the presence of one obstacle to the ejection of the blood of the left ventricle towards the Aorte. That involves, upstream, an increase in the pressure (barometric overload) on the level of the left ventricle which will thicken (Hypertrophie) by compensation, and downstream, of a maladjustment of the cardiac Débit with the effort, person in charge of the traditional clinical demonstrations occurring with the effort: breathlessness (Dyspnea), thoracic Pain correspondent with a Angor and syncope.

The diagnosis is easy with the cardiac Auscultation by its systolic breath hard and raspy with the aortic hearth, it evolves tardily to the left Cardiac failure, then of very bad Pronostic. The risk of Sudden death is high in the most severe forms. As long as the patient carrying the aortic contracting does not complain about nothing and that the echocardiography does not comprise a pejorative criterion, the clinical and echographic monitoring is the rule. As soon as the symptoms appear or that aortic surface passes in lower part of a certain value, the only treatment consists of a cardiac Chirurgie: the surgical valvular replacement.

Anatomical recall

The aortic valve is made of an elastic fabric. It is located between the left ventricle and the Aorte. It usually made up of three cusps flexible is separated by commissures .

The aortic valve is closed during the Systole and is opened during the ventricular Diastole.

Its role is to prevent the backward flow of blood of the aorta towards the left ventricle.

In a normal state, it does not constitute a significant obstacle during the ejection of blood in systole: the difference in pressure between the upstream and the downstream (gradient) is weak and about 5 mmHg. In the same way, the surface of the valve, ( aortic surface ) is about 2 to 4 cm ².

Anatomical causes and aspects

In its most common form, the contracting degenerative, is calcified ( disease of Monckeberg ): progressive calcification of the valvular ring and sigmoid, outcome to a motionless calcified block, while the commissures remain free. Much more rarely, it can be of rheumatic origin , i.e. séquellaire of an infection with Streptocoque S pyogenes. In this case, there exists a thickening of the valve with welding of commissures and retraction of the free edges. Calcifications can appear tardily.

It can also be a question of an anomaly of birth of the valve (congenital): presence of two cusps instead of three (bicuspidie), presence of a membrane (being able to go until the presence of a fibrous diaphragm) to the top (know-valvular, rarer), or in lower part (under-valvular) of the valve.

The contracting of the aortic valve can be associated with an escape with the latter (insufficiency of the valve) to a more or less marked degree. One then speaks about aortic disease .

Mechanism

The aortic contracting forms an obstacle with the ejection of blood between the left ventricle and the aorta during the Systole, as soon as valvular surface is lower than 1 cm2. That has as a consequence:

the constitution of a gradient of left pressure ventricle - aorta increased;
a lengthening of the phase of ventricular ejection left;
an increase the speed of blood during the left ventricular ejection (it is this parameter which is detected with the cardiac Doppler);
an increase in the left ventricular systolic pressure (barometric overload) with thickening of the walls (Hypertrophy) to fight against that;
a relative insufficiency (functional insufficiency) of the flow in the coronary arteries by increase in the mass and the work of the left ventricle, without sufficient increase in the coronary flow (Effect Venturi);

In the severe forms, there exists a maladjustment of the cardiac Débit with the effort, involving a Cardiac failure, to see a transitory draining of the cardiac pump (syncope with the effort.

In the long run, the cardiac muscle can worsen in a reversible or irreversible way, with fall of the Fraction of ejection. The cardiac deterioration of the cells can facilitate occurred of turbid of the ventricular rate/rhythm being able to lead to a syncope or a Sudden death.

Diagnosis

Symptoms

A moderate aortic contracting does not involve any symptom.

Occurred of a symptom signs, a priori , a more severe aortic contracting which can appear by:

breathlessness (Dyspnea) with the effort;
of the thoracic pains correspondent with a Angor of effort;
a syncope occurring typically with the effort.

At a stage more evolved/moved, can appear other signs testifying to a Cardiac failure, of which oedemas of the lower extremities.

Physical signs

The cardiac Sounding watch a breath éjectionnel: it is classically systolic, being reinforced in its medium ( méso-systolic ), qualified the hard one or the raspy one. He is heard as well as possible at the left edge of the Sternum in his upper part ( aortic hearth ) and also audible on the level of the neck ( irradiation towards the carotid S . He is opposed thus to the breath, known as, of regurgitation (at the time of a mitral Insuffisance for example), softer, and especially constant during all the systole.

The second noise of the heart (called B2), corresponding to the aortic closing of the cusps, is decreased, even abolished, if these last are motionless.

The sound record and the carotidogramme are old techniques intended to visualize on paper the characteristics of the breath and the pulse of the carotid. They are not used any more nowadays.

In the serious forms, signs of Cardiac failure are present.

Electrocardiogram

The found anomalies are not specific, are inconstant and prejudge only little the gravity of the attack.

One can find signs of Hypertrophie ventricular left (HVG) of systolic type (with a negative wave T in apical derivations), even a block of left branch more or less complete (widening of the QRS).

More rarely one can find signs of hypertrophy of the left auricle (wave P widened)

Sometimes the aortic contracting can become complicated of a ventricular block auriculo more or less complete by infiltration of the ways of conduction (Faisceau of His) by calcifications.

Thoracic radiography

It brings only little of elements.

The cardiac silhouette is often widened ( cardiomégalie ) with sometimes a widening of the higher Médiastin corresponding to a dilation of the thoracic Aorte or to a modification of its plan which becomes more longitudinal ( unfolding of the aorta ).

The valve, itself, are invisible, except if it comprises calcifications.

One will seek signs of left cardiac failure: increase in the visibility of the pulmonary hiles being able to go until the pulmonary edema massive.

cardiac Echo-Doppler

The echocardiography, coupled with the Doppler, is the key examination making it possible to confirm the diagnosis and to estimate severity and its repercussion of it on the muscle.

It allows:

to specify the valvular anatomy and the cause of the aortic contracting;
to seek calcifications of the valve;
to measure the amplitude of opening of the aortic valve;
to appreciate the function of the cardiac muscle (calculation of the Fraction of ejection), the presence or not of a Hypertrophy of the walls.

The Doppler makes it possible to quantify the severity of the aortic contracting while being based on:

the measurement an increased speed of blood on the level of the aortic opening testifying to a difference in pressure between the left ventricle and the aorta (gradient of pressure) increased;
an evaluation of aortic valvular surface by the equation of continuity (surface sous-aortique*vitess aortic sous-aortique=vitess aortique*surface valvular).

Doppler also allows research a aortic Insuffisance associated.

Catheterization and cardiac angiography

This examination consists of a measurement of the pressures and flows, directly in the cardiac cavities, like with a opacification of these last by injection of a product of iodized contrast. It is coupled in rule with a Coronarographie.

It allows:

to confirm the degree of the contracting if echography is litigious;
to make a cardiac assessment with an aim of a surgical valvular replacement (cf will infra).

The injection in the ascending thoracic aorta of a radiographic product of contrast (aortography known-sigmoïdienne) research a possible associated aortic insufficiency and assembles know-valvular aortic dilation.

Injection in the left ventricle (left ventriculographie), when the aortic valve can be crossed quantifies the systolic function of the cardiac muscle (Fraction of ejection).

The injection in the coronary arteries (coronarography) makes it possible to see whether there exist contractings of these arteries likely to be repaired in the event of valvular replacement.

The measurement of the pressures makes it possible to calculate the gradient between the left ventricle and the aorta, and to calculate aortic surface (provided the contracting can be crossed) by taking account of the cardiac flow.

The measurement of the pressures on the level of the right heart brings information on the risk of the valvular intervention of replacement. It also allows the measurement of the cardiac flow.

Other examinations

The carotidogramme and the phonocardiogram are now abandoned techniques.

The echography trans-oesophagienne makes it possible to measure the surface of the valve directly, provided that the latter is not altered too much (what is generally the case when the contracting is significant).

The echography of stress makes it possible to better specify the values if the contracting is regarded as in extreme cases of the significativity. In the event of deterioration of the cardiac muscular function, it makes it possible to evaluate its possibilities of recovery after the intervention.

Evolution

The patient carrying an aortic contracting, tightened even enough, often does not complain about nothing: he is known as asymptomatic. The appearance of symptoms is a sign of gravity because the lifespan of the patient is then significantly reduced if it is not operated. Average survival after the appearance of the first signs is of 5ans in the event of breathlessness to the effort (Dyspnée), of 4ans in the event of thoracic pains with the effort (Angor), 3 years in the event of loss of consciousness to the effort, and two years if the patient presents signs of valvulopathy]], there exists a risk of [[infectious endocarditis]] but this risk is quite less than during the valvular escapes. A preventive medication of this complication is necessary. [[Statine]] the S were proposed to try to limit the progression of the disease. The results are, for the moment, mitigés {{in}} [http://content.onlinejacc.org/cgi/content/abstract/49/5/554 '' Rosuvastatin affecting aortic valve endothelium to slow fox trot the progression off aortic stenosis ''], Luis Mr. Moura, Sandra F. Ramos, Jose L. Zamorano, Isabel Mr. Barros, MDLuis F. Azevedo, Francisco Rocha-Gonçalves, Nalini Mr. Rajamannan, J Am coll Cardiol, 2007; 49:554 - 561 {{in}} [http://content.nejm.org/cgi/content/abstract/352/23/2389 '' has off Randomized trial intensive lipid-lowering therapy in calcific aortic stenosis" "], S. Joanna Cowell, David E. Newby, Robin J. Prescott, Peter Bloomfield, John Reid, David B. Northridge, Nicholas A. Boon, New Eng J Med, 2005; 352: 2389-2397. ===Traitement chirugical=== The surgical replacement of the valve remains the treatment of choice when the aortic contracting is sufficiently tightened and that the patient becomes symptomatic (complains about one breathlessness to the effort, of angor, faintnesses with the effort). One can also propose a surgery at a patient complaining about nothing (asymptomatic) but to which examinations successive and brought closer show that the valve narrows in an accelerated way (over several months). It requires to resort to one [[cardiac surgery]] with installation of one [[extracorporal circulation]] intended to maintain the irrigation of the organization in blood during the cardiac arrest necessary at the time of intervention ('' surgery in open heart ''). The sick valve is removed and replaced by an artificial valve. This one is known as '' mechanical '' when it is out of metal or synthetic materials. It is known as '' [[bioprothèse valvular|biological]] '' (still called '' [[bioprothèse valvular|bioprothèse]] '') when it consists of treated animal fabrics (not of risk of [[allergy]] or of rejection as at the time of one [[Clerc's Office (medicine)|graft]]. The advantage of the mechanical valve in is its solidity. Its disadvantage is the need for a treatment by [[anticoagulant]] S with life with its constraints and its risks. The advantage of a biological valve is the absence of need for an anticoagulant treatment. It is degraded on the other hand with time (between 5 and 10 years), obliging sometimes with a new valvular replacement. The choice between the two types of prostheses is function of the ground, and sometimes choice of the patient: * A advanced age and/or a counter-indication with the anticoagulant treatment with the long course make choose a biological prosthesis. * Conversely, a mechanical prosthesis is the logical choice at a younger patient, because of higher longevity of this type of prosthesis, * However, among certain young patients, practitioner in particular an sports activity at the traumatic risk, or not wishing to follow anticoagulant treatment to the long course, it is possible to propose the installation of a bioprothèse. It exempts anticoagulant treatment but the patients being clearly informed of the strong probability of having to resort to a new valvular replacement in the 10 years. Another particular case is that of the woman young, likely to be pregnant (a pregnancy under anticoagulant involves big risks). The essential problem of the surgery of the aortic contracting remains that they are primarily old patients, even very old and that the risk of the intervention must be carefully evaluated and discussed with this last. ==Recommandations== There exist several documents acting as recommendations on the assumption of responsibility of the aortic contracting. Those, American, go back to 1998 and were revised in 2006Bonow RO, Carabello BA, Chatterjee K, and Als. [http://www.guideline.gov/summary/summary.aspx?doc_id=9470 '' ACC/AHA 2006 guideline for the management off patient with valvular heart disease. With carryforward off the American College off Cardiology/American Heart Association Task force one Practice Guidelines ''], J Am coll Cardiol 2006; 48 (3): e1-148. Those, European, go back to 2007Vahanian has, Baumgartner H, Bax J and Als, [http://eurheartj.oxfordjournals.org/cgi/content/extract/28/2/230 '' Guidelines one the management off valvular heart disease: The Task force one the Management off Valvular Heart Disease off the European Society off Cardiology ''], European Heart Newspaper, 2007; 28: 230-268. The French company of Cardiology also published its clean recommandationTribouilloy C, De Gevigney G, Acar C and Als. [http://www.cardio-sfc.org/pdf/reco-valvulo.pdf '' Recommandations of the French company of cardiology concerning the assumption of responsibility of the acquired valvulopathies and the dysfonctions of valvular prosthesis ''], Arch Badly Heart, 2005; 98 (suppl n° 2): 5-61. The difference in assumption of responsibility is due to nuances: not taken into account of [[body surface]] for the quantification of aortic surface for American, places more important of [[test of effort]] to the asymptomatic patient (complaining about nothing) to decide intervention among Europeans… ==Références== * {{in}} '' Valvular Aortic Stenosis: Disease Severity and Timing off Intervention '', C Otto, J Am coll Cardiol 2006; 47: 2141-51 {{gate medicine}} [[Category: Cardiovascular disease]] [[of: Aortenstenose (angeboren)]] [[in: Aortic valve stenosis]] [[be: Estenosis aórtica]] [[N: Aortastenose]] [[No: Aortastenose]] [[Pt: Estenose aórtica]] [[sv: Aortastenos

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