Kembara Xtra - Medicine - Mitral Stenosis

Kembara Xtra - Medicine - Mitral Stenosis 
Mitral stenosis (MS) is a narrowing of the valve area that prevents the left ventricular (LV) from receiving blood, increasing the pressure in the left atrium (LA), and as a result, raising the pulmonary venous pressure.
The average valve orifice is 4 to 5 cm2, and symptoms usually appear when it is less than 2.5 cm2.
The disease's stage is utilized to determine the best course of treatment (1).
Stage A is "at risk of MS" and consists of mild valve doming with normal flow velocity and no hemodynamic obstruction or symptoms. Stage B is "progressive MS" and consists of increased diastolic doming with increased flow velocity, but MVA >1.5 cm2 and diastolic pressure half time 150 ms. Stage C is "asymptomatic severe MS" and consists of diastolic doming, MVA 1.5 cm2, diastolic pressure
Below are some more etiologies that are covered.

Epidemiology 
RHD continues to have a substantial global incidence, with 282,000 new cases and 305,000 fatalities each year.
The continental United States continues to have a low incidence of rheumatic disease. Because it is no longer nationally reportable, the annual incidence of acute rheumatic fever (ARF) in the mainland United States is unclear, but it is greater in Hawaii and American Samoa.
 Predominant age: The third and fourth decades are when symptoms are most common.
- Patients with severe valve obstruction present in their sixth decade of life in North America and Europe, where the prevalence is 1 case per 100,000 people. In Africa, there are 35 diseases per 100,000 people, and severe illnesses frequently manifest in teenagers.
 Female is more prevalent than male (3:1)

Pathophysiology and Etiology 
Blood flow between the left atrium and the right ventricle is obstructed by a narrowing of the mitral valve (MV) orifice. This results in higher LA pressure and impaired LV filling during diastole.
Increased LA pressure gradually leads to pulmonary hypertension (HTN) and congestion in the lungs by passive transmission (or "back pressure").
Atrial fibrosis and dilatation brought on by chronic LA pressure overload lead to atrial fibrillation.
The anatomic changes of severe MS are believed to be secondary to recurrent episodes of ARF as well as a chronic autoimmune process brought on by cross-reactivity between a streptococcal protein and valve tissue. Rheumatic fever is the most common cause of these changes. It is characterized by pathognomonic commissural fusion, leaflet thickening, and the "fish mouth appearance" seen with RHD.
Aging (extension of mitral annular calcification) Rare causes: autoimmune: systemic lupus erythematosus (SLE), rheumatoid arthritis, malignant carcinoid, Whipple disease, methysergide therapy; and other acquired: LA myxoma, LA thrombus, endomyocardial fibrosis

Risk Elements 
The two highest risk factors are ARF and RHD.
A rheumatogenic group A streptococci (GAS)-induced episode of untreated pharyngitis in a genetically susceptible host results in ARF 2 to 3 weeks later.
RHD is the term used to describe the chronic valvular damage brought on by a single severe episode of ARF, numerous recurring episodes of ARF, and/or the ongoing autoimmune process brought on by the cross-reactivity of streptococcal protein with valve tissue.
- 20 years after being diagnosed with ARF, MS will eventually develop in 30–40% of rheumatic fever patients.
- Repeated infections can quicken the disease's development.
- The transmission of streptococcal infection is favored by low socioeconomic level (i.e., crowded settings).
Chest irradiation (raising tissue fibrosis) and aging (increasing valvular calcification)

Basic Prevention 
Early detection and treatment of GAS infection in at-risk groups; application of the Jones criteria to identify the key signs and symptoms of ARF Echocardiographic screening has been demonstrated to improve the diagnosis of RHD in asymptomatic individuals living in high-prevalence areas.

Accompanying Conditions 
Atrial fibrillation (30–40% of symptomatic patients); associated valve abnormalities brought on by chronic inflammation (aortic stenosis; aortic insufficiency); pulmonary hypertension; right heart failure; systemic embolism; stroke; pulmonary embolism; infectious endocarditis; 1–5%; etc.;

Diagnosis 
ARF or RHD history; severity varies by valve location; early cases are typically asymptomatic.
The late 30s to early 40s are the typical onset years for rheumatic valvular disease symptoms. 20 to 40 years after the infection, the latent period. In some high incidence locations, there is rapid advancement.
Dyspnea with exertion, decreased exercise tolerance, chest discomfort, palpitations, hoarseness, hemoptysis, tiredness, paroxysmal nocturnal dyspnea, atrial fibrillation, and embolic events are common presenting signs.
Jugular venous distention, hepatomegaly, ascites, and peripheral edema are signs of severe illness that indicate pulmonary HTN and right heart failure.
Other symptoms include hemoptysis (due to pulmonary vein rupture and bronchial circulation causing intraparenchymal hemorrhage), hoarseness (due to compression of the recurrent laryngeal nerve by an enlarged pulmonary artery or LA, Ortner syndrome), dysphagia (due to esophageal compression), chronic cough (due to the LA compressing the bronchi), and infective endocarditis.

clinical assessment 
Left lateral decubitus posture with diastolic thrill and elevated jugular venous pressure. In patients with pulmonary HTN, a right ventricular (RV) lift may be felt in the left parasternal region.
Auscultation reveals the classic murmur: prominent S1, opening snap, apical early decrescendo diastolic rumbling, and presystolic accentuation of the murmur (presystolic accentuation of the murmur is eliminated with atrial fibrillation). Low-pitched murmur is most audible at the apex while lying in the left lateral decubitus position.
- Exercise increases murmur, but Valsalva and rest reduce it.
With a mobile, noncalcified valve, the opening snap is loud and the murmur lasts throughout diastole and S1.
As MS becomes more severe, it becomes increasingly challenging to hear murmur. The length of the murmur indicates the severity. The opening snap and S1 could be weak or nonexistent.
Further assessment is necessary while searching for accompanying murmurs; a shorter S2 to O2 interval implies more severe MS.
 If pulmonary HTN is present, there may be right heart failure symptoms and an increased P2 high-pitched decrescendo diastolic murmur (Graham Steele murmur). RV lift is also visible.
Due to the involvement of RHD, additional related aortic or tricuspid murmurs may be detected.

Laboratory Results 
Initial examinations (lab, imaging)
ECG - LA enlargement, atrial fibrillation, and right ventricular hypertrophy (RVH) may be seen Chest radiograph - LA enlargement, straightening of the left heart border, a "double density," in the cardiac silhouette, and elevation of the left main stem bronchus Prominent pulmonary arteries at the hilum with rapid tapering, RVH, and edema pattern with Kerley A and B lines (late presentation
Exercise stress testing with Doppler echocardiography can also be taken into consideration in MS patients who have a discrepancy in their symptoms and signs and resting echo findings. TEE should be carried out if TTE images are nondiagnostic or if being considered for a PMBC to exclude thrombus in LA and evaluate severity of MR.
Routine diagnostic cardiac catheterization is not advised for the evaluation of MS. Class I recommendations are made when an echo is inconclusive and there is a discrepancy between the severity of the symptoms and the echo results. Class II recommendations are made to determine the cause of severe pulmonary HTN that is out of proportion to the echo results.
Class III recommendations: acceptable echo results; CT imaging: beneficial before surgery, especially to assess for concurrent coronary artery disease (CAD); may yield MVA estimations and LA cavity size.

Tests in the Future & Special Considerations
Clinical follow-up in 3 to 5 years is advised if the valve area is greater than 1.5 cm2 and the mean pressure gradient is less than 5 mm Hg.
If not, follow-up is frequently symptom-based.
Patients with severe MS symptoms require additional assessment for interventional/surgical treatment.
 Installation of a Holter monitor to rule out paroxysmal atrial fibrillation

Other/Diagnostic Procedures
Exercise testing is advised for patients who have clinical inconsistency.
A TTE's valve anatomy is evaluated by Wilkins score in order to determine whether a patient is a candidate for surgery.
The following pathologic alterations are caused by rheumatic fever: chordal shortening, commissural fusion, leaflet thickening, and leaflet calcification. MVA is defined as: Normal: 4 to 6 cm2, progressive MS: >1.5 cm2, asymptomatic severe MS: 1.5 cm2, severe MS: 1.5 cm2, and very severe MS: 1.0 cm2.

Management 
Treatment is based on the degree of stenosis and the symptoms.
Medical management is an option for those with valvular areas >1.5 cm2 but no symptoms.
MS is typically progressive, and medical treatment merely serves to put off the need for effective treatment. It involves: - Rheumatic fever preventive therapy - Dyspnea and exercise tolerance therapy - Controlling the ventricular rate whether in sinus rhythm or atrial fibrillation - Anticoagulation for thromboembolic event prevention

Medication 
Initial Line
Use of anticoagulation for the prevention of thromboembolism - Class I recommendations; MS and atrial fibrillation or history of atrial fibrillation; MS and prior embolic event; MS and LA thrombus; or MS and prior embolic event; Class IIB recommendations; Patients with enlarged LA and spontaneous contrast on echo; Warfarin is the accepted anticoagulant for people with rheumatic MV disease (international normalized ratio range: 2 to 3). Heparin is utilized for anticoagulation with atrial fibrillation because the new oral anticoagulants (factor Xa inhibitor and direct thrombin inhibitor) have not been approved for use in atrial fibrillation with individuals who have moderate-to-severe MS.
For individuals with a history of rheumatic fever, antibiotic prophylaxis against rheumatic fever and/or carditis is advised. Numerous variables affect secondary prophylaxis, including age of the patient, number of previous episodes, length of time since previous infection, risk of GAS, and existence or absence of cardiac involvement.
Unless there are other symptoms, antibiotic prophylaxis against infective endocarditis is not typically advised.
Consider cardioversion, especially in patients with mild MS and a recent diagnosis of the disease. Diuretics are useful for congestive symptoms and symptomatic heart failure. -Blockers or nondihydropyridine calcium channel blockers are used to control heart rate in sinus rhythm and atrial fibrillation to allow adequate diastolic filling and reduce LA diastolic pressure tachycardia or exertional symptoms (class IIa).
If beta-blockers and calcium channel blockers are ineffective in reducing fast ventricular rate, Second Line One may also take amiodarone or digitalis into account. When treating patients with symptomatic systolic dysfunction, think about digitalis.

Surgical Techniques 
Balloon valvotomy, open mitral commissurotomy, closed mitral commissurotomy, and MV replacement are examples of surgical procedures.
Surgery is an option for patients with severe MS with symptoms that fall within NYHA levels III and IV.
Patients who have significant aortic valve disease, moderate TR or TS, a LA thrombus, a valve area >1.5 cm2, moderate or severe MR, severe or bicommissural calcifications, or concurrent CAD needing bypass surgery are NOT candidates for PMBC.
● Per the 2014 AHA/ACC valvular heart disease guidelines (which is similar to the 2017 European Society of Cardiology guidelines), PMBC is recommended for patients with the following: – Symptomatic severe MS (MVA <1.5 cm2) and favorable valve morphology – Symptomatic severe MS with severe (NYHA III/IV) symptoms who have suboptimal valve anatomy and are not candidates or are high risk for surgery– Asymptomatic very severe MS (MVA <1.0 cm2) and favorable valve anatomy in the absence of contraindications– Asymptomatic severe MS and favorable valve morphology with new-onset atrial fibrillation in absence of contraindications– Symptomatic patients with MVA >1.5 cm2 if there is evidence of hemodynamically significant MS during exercise ● MV surgery is recommended for patients with the following: – Severe MS with severe symptoms (NYHA classes III and IV), who are not high-risk surgical candidates, and balloon valvotomy is contraindicated or failed PMBC – Severe MS and recurrent embolic events while receiving adequate anticoagulation that requires LA appendage excision – Severe MS in patients undergoing other cardiac surgery or possibly in patients with moderate MS undergoing other cardiac surgery● Patient’s age, bleeding risk, and other comorbidities prior to deciding if patient should have a prosthetic versus mechanical valve

pregnant women's issues
Pregnancy-related volume enlargement can make heart failure symptoms worse. Patients with known severe MS should consider pre-pregnancy consultations with a cardiologist.
If anticoagulation is necessary in the second and third trimesters, warfarin (Coumadin) is regarded as reasonably safe.
Prior to labor and delivery, unfractionated heparin is preferable.

Take Action 
Inform patients that while MS often progresses gradually, atrial fibrillation may appear suddenly and quickly prove lethal. For noticeably increasing symptoms, dial 911.
The frequency of follow-up will depend on the severity of the MS and the patient's symptoms. In asymptomatic patients with any degree of MS, echocardiographic surveillance is performed as follows: extremely severe (MVA 1.0 cm2) MS: annually; severe (MVA 1.5 cm2) MS: every 1 to 2 years; mild or moderate (MVA >1.5 cm2) MS: every 3 to 5 years.
Symptomatic patients are regularly monitored based on clinical response to alter therapy and prepare definitive treatment for asymptomatic people, who get an annual history and physical.

Diet 
Limiting salt intake to treat pulmonary congestion

Prognosis 
Natural history — 10 to 30 years of asymptomatic latent phase following rheumatic fever. For patients who are asymptomatic or barely symptomatic, the 10-year survival rate is 80%. Only 0-15% of people survive 10 years after the onset of incapacitating symptoms. 3 years is the average survival time with substantial pulmonary HTN.
Commissurotomy reduces stenosis effectively but does not cure it. Sometimes restenosis develops, and it may be early (5 years) or late (>20 years).

Complications 
Atrial fibrillation, systemic embolization, left and right heart failure, pulmonary hypertension, pulmonary vasoconstriction, hepatic congestion, and bacterial endocarditis

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