Aortic regurgitation

Aortic regurgitation is caused by the aortic valve not closing. Aortic valve insufficiency can be caused by 'dilation of the aortic root or damage to the valve itself, both as a result of acquired and congenital defects. In the pathophysiology of aortic regurgitation, ``volume overload of the left ventricle'' dominates. Diagnosis of this defect is sometimes complicated by a 'long asymptomatic period. In addition to clinical examination is the basic examination method of echocardiography. Cardiosurgical intervention and catheter replacement of the valve can be used in the treatment.

Etiopathogenesis
The causes of the development of aortic regurgitation can be divided into two main categories - dilation of the aortic root and involvement of the valve itself. Dilation of the aorta (not only its root) can be the result of genetic syndromes, especially Marfan syndrome and Ehlers-Danlos syndrome. There is also an increased incidence in ankylosing spondyloarthritis. Another significant cause of aortic root dilatation is '' "hypertension" with consequences in the form of increased stiffness of the aortic wall, loss of elasticity and atherosclerotic damage. Aortic regurgitation also often occurs on the basis of infective endocarditis, bicuspid valves, as part of post-rheumatic disease, myxomatous disease, calcification (degenerative) valve disease, chest trauma or aortic dissection. Other less frequent causes are involvement of the aortic valve in systemic inflammatory diseases (SLE), infiltrative and persistent diseases or aortitis. Also often occurs 'together with aortic stenosis. The pathophysiology of aortic regurgitation is dominated by volume overload of the left ventricle, which in most cases is chronically progressive. The left ventricle thus dilates over time and a picture of eccentric hypertrophy develops. In the initial stages, sometimes even for several years, the dilatation may not be accompanied by a decrease in the systolic function of the left ventricle or a significant increase in filling pressures chambers, and thus diastolic dysfunction. This defect therefore remains 'asymptomatic for a very long time, which complicates not only the diagnosis but also the treatment procedure, because there is only a relatively limited period of time for effective intervention before irreversible impairment of the systolic function of the ventricle. Left ventricular dilatation leading to increased consumption of the myocardium, its systolic (and later also diastolic) dysfunction together with reduced diastolic blood pressure eventually lead to hypoxic involvement of the myocardium and "left-sided heart failure" ''. This can be further complicated by secondary mitral regurgitation, which together with reduced ventricular compliance due to progressive dilation leads to increased left atrial pressures.

Clinical picture
Aortic regurgitation is usually asymptomatic for a long time (up to decades). It is manifested by fatigue, exertion dyspnea, loss of performance and less often by angina pectoris.  Charakteristické je zvýšení pulzního tlaku při snížení diastolického tlaku při současném zvýšení tlaku systolického. Pacienti s aortální regurgitací špatně tolerují fibrilaci síní a extrasystolií kvůli zvýšení postextrasystolického objemu komory. Naopak je udávána do rozvoje srdečního selhání dobrá tolerance zátěže, kdy tachykardie zkracuje trvání diastoly, a tedy i regurgitace. Pacienti s akutně vzniklou aortální regurgitací se prezentují obrazem plicního edému a kardiogenního šoku.

Physical Finding
On auscultation, we detect a blow''diastolic decrescendo' murmur above the aortic orifice with a maximum at Erb's point (3.-4 . intercostal parasternal). Austin Flint diastolic mitral murmur reminiscent of [[mitral stenosis|mitral stenosis] may be heard at the tip ], which is caused by the premature closure of the anterior leaflet of the mitral valve by the flow of regurgitated blood from the aorta. mitral orifice. The already mentioned wide range of systolic and diastolic blood pressure is typical, which has its correlate in the nimble Corrigan's pulse on the carotids.

Signs of advanced disability are, for example, Quincke's capillary sign (the edge of the lunula pulsates when the nail is pressed), Musset's sign (shaking of the head with pulsation) and Müller's sign (shaking of the uvula with a pulse).

Diagnosis
Transthoracic and esophageal echocardiography is the basic diagnostic tool for aortic stenosis. It is not unusual for aortic regurgitation to be an incidental finding in asymptomatic patients, even in the case of this examination. 'X-ray of the chest usually reveals an enlargement of the cardiac shadow, dilatation in the area of ​​the ascending aorta, or signs of congestion in the small circulation. ECG is also non-specific, usually signs of left ventricular hypertrophy and load, or a tilt of the cardiac axis to the left, are detected. Magnetic resonance imaging or computed tomography is mainly used to assess dilatation of the aorta or more detailed imaging of other structures. Cardiac catheterization serves to rule out ischemic heart disease. Examination of natriuretic peptides is also appropriate in selected patients.

Treatment
Patients with hemodynamically insignificant and asymptomatic aortic regurgitation usually do not require specific therapy. However, this is necessary in case of arterial hypertension. In hypertensive patients and incipient left ventricular dilatation, we try to reduce diastolic hypertension medically by administering ACE inhibitors, which also have a positive effect on remodeling, as well as calcium channel blockers and, in symptomatic patients, diuretics. .  Beta blockers must be given with caution due to possible bradycardia, which is poorly tolerated by patients.

Treatment methods for significant aortic regurgitation are cardiosurgical aortic valve replacement or 'aortic valve and root replacement (Bentall operation) with dilatation of the bulb and ascending aorta. In indicated cases, it is also possible to perform valve-preserving operations, e.g. for dilatation of the aorta with normal morphology of the aortic valve leaflets. < ref name="Article 7"> Operative treatment is indicated in ``symptomatic patients with significant aortic regurgitation, in ``asymptomatic patients with systolic dysfunction or significant left ventricular dilatation, or also in significant dilatation of the ascending aorta. Moderately significant aortic regurgitation can be solved surgically in certain patients with a simultaneous operation on another valve, on the aorta or aortocoronary bypass. An increasingly developing technique that it is mainly used in high-risk patients, it is a catheter replacement of the aortic valve (TAVI, or TAVR). The prognosis of asymptomatic aortic regurgitation without left ventricular systolic dysfunction is good. In symptomatic patients with the development of heart failure or significant dilatation of the left ventricle, the prognosis is worse, without surgery the mortality rate is approximately 20% per year. '', ideally before the development of symptoms and significant systolic dysfunction, when patients' prognosis is best.

Summary Video and Listening Finding
preview|Video in English, definition, pathogenesis, symptoms, complications, treatment.|573x573pixelů

Related Articles

 * Congenital heart defects • Acquired heart defects
 * Aorta abdominalis • Aorta thoracica
 * Aortic Stenosis • Abdominal Aortic Bulge
 * Elastic artery (histological preparation)

Links

 * Richard et al. Internal 3rd edition. Triton, 2020. ISBN 978-80-7553-782-9.
 * Braunwald's Heart Disease : A Textbook of Cardiovascular Medicine. 10th Edition release. 2015. ISBN 978-0-323-29429-4.
 * SILBERNAGL, Stefan a Florian LANG. Atlas patofyziologie. 2. vydání vydání. 2012. ISBN 978-80-247-3555-9.SILBERNAGL,Stefan and Florian LANG. Atlas of Pathophysiology. 2nd edition of the edition. 2012. ISBN 978-80-247-3555-9.
 * OTTO, Catherine M. Textbook of Clinical Echocardiography. 6th edition. Elsevier, 2018. ISBN 978-0-323-48048-2.
 * HLUBOCKÁ, Zuzana. Valvular defects [lecture on the subject Cardiovascular Medicine, field of General Medicine, 1st Faculty of Medicine, UK]. Prague. -. Also available from
 * BAUMGARTNER, Helmut, Volkmar FALK, and Jeroen J BAX. 2017 ESC/EACTS Guidelines for the management of valvular heart disease. European Heart Journal. 2017, year 36, vol. 38, pp. 2739-2791, ISSN 0195-668X.
 * STANEK, Vladimir. Cardiology in practice. 1st edition. Prague: Axonite CZ, 2014. ISBN 978-80-904899-7-4.