Mitral valve stenosis

Classification according to ICD-10
I05.1	Rheumatic mitral valve stenosis
I34.2	Non-rheumatic mitral valve stenosis
Q23.2	Congenital mitral valve stenosis
ICD-10 online (WHO version 2019)

The mitral or mitral stenosis is a valvular heart disease , wherein the opening of the mitral valve is narrowed by a "bonding" of the Mitralklapensegel. This leads to a disturbed filling of the left ventricle between two heart actions (during diastole ) .

Epidemiology

Mitral valve stenosis is one of the most common acquired heart valve defects worldwide and affects women more than men. In the industrialized countries which could incidence through the consistent use of penicillin with infections streptococci are significantly reduced in the past, it that there nowadays rarely occurs as acquired aortic valve stenosis and mitral regurgitation .

In around 40% of cases, mitral stenosis is also accompanied by aortic stenosis .

etiology

By far the most common cause of mitral stenosis is rheumatic fever and the associated (verrucous) endocarditis (inflammation of the inner lining of the heart; endocarditis verrucosa rheumatica ). It typically occurs with a latency period of 20 to 30 years after the febrile illness. Endocarditis due to a bacterial infection or congenital mitral stenosis ( Lutembacher syndrome ) are less common.

Pathophysiology

Mitral stenosis

The stenosis of the mitral valve is caused by inflammatory and degenerative changes in the valve cusps and the chordae tendineae . Fibroses and calcifications lead to a progressive restriction in the ability of the valve apparatus to stretch and move.

The normal valve opening area is 4–6 cm². If this opening area is reduced by more than half, hemodynamically effective disturbances occur with the formation of a pressure gradient between the left atrium and the left ventricle. A tachycardia leads to an additional increase in this pressure gradient and thus an increase in the pressure in the left atrium, since the diastole is shortened more than the systole and therefore less time is available for the blood to flow through the valve opening. On the one hand, this results in dilation (stretching) and, in chronic mitral stenosis, an enlargement of the left atrium, which favors the occurrence of atrial fibrillation and is usually present in severe mitral stenosis, and on the other hand, pulmonary hypertension due to the obstructed outflow from the pulmonary veins . As the disease progresses, this in turn puts pressure on the right heart and, as a result of right heart dilation, also leads to right heart failure .

clinic

A key symptom is dyspnea (shortness of breath) caused by the backflow of blood in the lungs . The dyspnea usually only occurs during exercise, when the cardiac output is increased. In severe stenoses, resting dyspnea can also occur. Another symptom of severe mitral stenosis can be hemoptysis (coughing up blood), which occurs particularly at night with intense dyspnea. In general, the physical performance of affected patients is reduced.

If the disease has been untreated for many years, a so-called mitral face ( facies mitralis ) with “red cheeks” (so-called mitral cheeks), peripheral cyanosis (acrocyanosis) and signs of right heart failure can appear.

Sometimes mitral stenosis only becomes apparent when a tachyarrhythmia absoluta is diagnosed with atrial fibrillation . This occurs regularly in advanced mitral stenosis and can be diagnostic. Often the first manifestation leading to a diagnosis is a thromboembolism caused by atrial fibrillation .

Diagnosis

The suspected diagnosis is based on anamnesis and clinic. The leading noise in auscultation is a low-frequency diastolic with a decrescendo character. The maximum punctum is located in the 5th ICR (intercostal space) on the left or near the apex of the heart. A presystolic noise can also be heard.

Other noise phenomena that can be detected during auscultation can be:

• throbbing (or “knocking”) 1st heart sound with flexible valve leaflets, weakened with immobile valve leaflets
• 2. Heart sound often louder to the left of the sternum
• Mitral valve opening tone or mitral opening tone (MÖT) as the (third) tone before the diastolic

The percussion shows an elapsed heart waist.

Apparatus diagnostics

The other diagnostically usable changes include:

• Chest x-ray: The chest x-ray shows a coarsening of the left heart waist, which is caused by a bulging of the left atrium and the left auricle . In the lateral picture after Ösophagusbreischluck a narrowing of the esophagus show through the left atrium. Basal Kerley B-lines and a narrowing of the retrosternal space may be found as signs of pulmonary hypertension .
• ECG: The ECG often shows an excessive or bimodal P wave ( p mitral ) as an expression of atrial dilatation. Atrial fibrillation or atrial flutter may also be present. Signs of right heart strain appear in the form of a steep type or right type of the heart axis only at an advanced stage.
• Echocardiography The echocardiography and Doppler echocardiography allows both the determination of the valve opening area, and the calculation of the pressure gradient. In addition, any accompanying mitral regurgitation can be secured.
• Right heart catheter examination: With the right heart catheter examination and additional ergometric stress, the pulmonary pressure increases beyond the normal level.
• Left heart catheter examination: The left heart catheter examination allows a direct determination of the pressure gradient and the valve opening area. For this purpose, the pressure in the left ventricle and also the wedge pressure (using a pulmonary catheter ) can be determined.

Classification of severity

Mitral stenosis can be divided into three degrees of severity after determining the valve opening area (KÖF).

• Mild: KÖF larger than 1.5 cm²
• Moderate: KÖF 1.0 to 1.5 cm²
• Heavy: KÖF smaller than 1.0 cm²

There is also the possibility of a more complex classification:

stage	Flap opening area	diastolic blood flow, ml / s 1	Cardiac output, l / min 1	Pressure gradient, mm Hg 2
very mild	> 2.0 cm 2	300	10.0 - 12.0	5 - 8
mild	> 1.5 cm 2 - 2.0 cm 2	200	7.0-9.0	8-12
medium	> 1.0 cm 2 - 1.5 cm 2	150-175	5.5 - 6.5	12-15
heavy	less than / equal to 1.0 cm 2	125	4.5-5.0	> 15

¹ at a heart rate of 60 / min

²in the presence of normal pulmonary artery pressure. The transition between mild and medium form is not exactly defined

therapy

The therapeutic options include conservative control of complications and surgical (alternatively catheter) correction of the stenosis.

In the case of mild mitral stenosis, conservative therapy through physical rest and the administration of diuretics (water products) can be used. If there is also relevant pulmonary hypertension, therapy with vasodilators (vasodilating substances, e.g. nitrates ) can be helpful.

If there is recurrent atrial fibrillation with a risk of cardiac embolism , anticoagulation with Marcumar should be carried out. If the atrial fibrillation is quickly transferred to the ventricles with the risk of pulmonary edema, digitalis glycosides and beta blockers or verapamil can be used to control the frequency.

ACE inhibitors are contraindicated.

Antibiotics should be taken consistently for prophylaxis of endocarditis before bloody procedures and in the event of febrile infections .

During surgery and anesthesia in patients with mitral stenosis, the heart rate should be kept low (between 60 and 80 beats / min) and the left ventricular preload should be kept high.

Surgical or interventional therapy is always advisable in the case of severe symptoms and severe mitral stenosis. Intervention should not be delayed too long, as the prognosis of mitral stenosis will otherwise worsen even after surgical therapy.

The following surgical / interventional procedures are available:

• Mitral valve valvuloplasty (expansion with a balloon catheter )
• Mitral valve commissurotomy (as a closed or open commissurotomy)
• Mitral valve reconstruction
• Mitral valve replacement ( biological or mechanical valve )

The usual manual stretching (usually the little finger was the right size) with "digital" access through the auricle is practically no longer carried out, which was previously carried out by the British surgeon Henry Souttar in 1925 .

forecast

In general, the prognosis for mitral valve narrowing is better than that of other heart valve defects. In severe stages, however, the lifespan of patients without treatment is significantly shortened. In stage NYHA III, around 60% of patients are still alive after five years without treatment. In the highest stage NYHA IV still around 15%. The leading causes of death are the insufficiency of the right heart, pulmonary edema resulting from the increase in pressure in the left atrium, and embolism . The five-year survival rate can be increased to over 80% with adequate surgical therapy. However, the operation also carries the risk of dying during it. Depending on the method and study, it is between one and five percent. The commissurotomy is less of a risk than a valve replacement.

literature

• Gerd Herold ao: Internal Medicine - A lecture-oriented presentation. 2005.
• Reinhard Larsen: Anesthesia and intensive medicine in cardiac, thoracic and vascular surgery. (1st edition 1986) 5th edition. Springer, Berlin / Heidelberg / New York et al. 1999, ISBN 3-540-65024-5 , pp. 223-235.
• Klaus Holldack, Klaus Gahl: Auscultation and percussion. Inspection and palpation. Thieme, Stuttgart 1955; 10th, revised edition, ibid. 1986, ISBN 3-13-352410-0 , pp. 148–157, 171 f., 178 f. and 196 f.

Individual evidence

1. ↑ Reinhard Larsen (1999), p. 224 f.
2. ^ American College of Cardiology / American Heart Association Task Force on Practice Guidelines; Society of Cardiovascular Anesthesiologists; Society for Cardiovascular Angiography and Interventions; Society of Thoracic Surgeons, RO Bonow, BA Carabello, C. Kanu, AC de Leon Jr, DP Faxon, MD Freed, WH Gaasch, BW Lytle, RA Nishimura, PT O'Gara, RA O'Rourke, CM Otto, PM Shah , JS Shanewise, SC Smith Jr, AK Jacobs, CD Adams, JL Anderson, EM Antman, DP Faxon, V. Fuster, JL Halperin, LF Hiratzka, SA Hunt, BW Lytle, R. Nishimura, RL Page, B. Riegel: ACC / AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology / American Heart Association Task Force on Practice Guidelines (writing committee to revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease) : developed in collaboration with the Society of Cardiovascular Anesthesiologists: endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons. In: Circulation. 114 (5), Aug 1, 2006, pp. E84 – e231. PMID 16880336
3. ↑ Table modified from SH Rahimtoola, A. Durairaj, A. Mehra, I. Nuno: Current evaluation and management of patients with mitral stenosis. In: Circulation. 106 (10), Sep 3, 2002, pp. 1183-1188. PMID 12208789
4. ↑ Reinhard Larsen (1999), pp. 232-235.
5. ↑ Ernst Kern : Seeing - Thinking - Acting of a surgeon in the 20th century. ecomed, Landsberg am Lech 2000, ISBN 3-609-20149-5 , p. 285.
6. ^ Herbert Renz-Polster , Steffen Krautzig: Basic textbook internal medicine. Munich / Jena 2008, pp. 166–169.

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !