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stenosis[stĕ-no´sis] (pl. steno´ses)
mi·tral ste·no·sis (MS),
mitral stenosisMitral valve obstruction Cardiology A sequela of rheumatic heart disease, primarily affecting ♀ and more common in developing nations Clinical Left-sided heart failure–DOE, orthopnea, paroxysmal nocturnal dyspnea; less commonly, hemoptysis, hoarseness, signs of right-sided heart failure; Sx may be triggered by A Fib, pregnancy or other stress–eg, RTI, endocarditis or other heart disease Examination Diastolic rumble after opening snap; S1 is usually load, because the mitral valve remains open by a transient gradient until closed by the systolic force; pulmonary HTN is indicated by a loud P2, right ventricular lift, ↑ neck veins, ascites, edema Workup Doppler echocardiography–↓ valve diameter, severity of stenosis Management Medical therapy in asymptomatic Pts–antibiotics for endocarditis; mild Sx–diuretics; with A Fib, digoxin, beta-blocker, or CCB; moderate Sx–balloon valvotomy if calcification not excessive, otherwise, valve repair or replacement. See Mitral valve.
mi·tral ste·no·sis(MS) (mī'trăl stĕ-nō'sis)
mitral stenosisNarrowing of the MITRAL VALVE of the heart. This is usually the result of damage from RHEUMATIC FEVER. The narrowing imposes a back pressure on the blood coming from the lungs and an early sign is breathlessness. The left ATRIUM enlarges and may beat irregularly (ATRIAL FIBRILLATION) and clots may form in the atrium. Disablement from reduced exercise tolerance may be severe and surgery may be required to widen or replace the damaged valve.
|Mean LOS:||16.5 days|
|Description:||SURGICAL: Cardiac Valve and Other Major Cardiothoracic Procedure With Cardiac Catheterization and With Major CC|
|Mean LOS:||7.4 days|
|Description:||SURGICAL: Cardiac Valve and Other Major Cardiothoracic Procedures With Cardiac Catheterization and Without CC or Major CC|
|Mean LOS:||12.5 days|
|Description:||SURGICAL: Cardiac Valve and Other Major Cardiothoracic Procedures Without Cardiac Catheterization and With Major CC|
|Mean LOS:||5.6 days|
|Description:||SURGICAL: Cardiac Valve and Other Major Cardiothoracic Procedures Without Cardiac Catheterization and Without CC or Major CC|
|Mean LOS:||3.3 days|
|Description:||MEDICAL: Cardiac Congenital and Valvular Disorders Without Major CC|
Mitral stenosis, a pathological narrowing of the orifice of the mitral valve, occurs when the mitral valve is unable to open fully. The opening of the mitral valve, normally 4 to 6 cm2 in area, is decreased to half normal size or even smaller because of a series of changes in valve structure. The mitral valve leaflets fuse together and become stiff and thickened by fibrosis and calcification. The chordae tendineae fuse together and shorten, and the valvular cusps lose their flexibility.
The mitral valve is located between the left atrium and the left ventricle. When mitral stenosis occurs, blood can flow from the left atrium to the left ventricle only if it is moved forward by an abnormally elevated left atrial pressure. The elevated left atrial pressure leads to increased pulmonary venous and capillary pressures, decreased pulmonary compliance, and exertional dyspnea. Left atrial dilatation, an increase in pulmonary artery pressure, and right ventricular hypertrophy follow as the heart compensates for the stenotic valve.
Complications of mitral stenosis can be serious. With no surgical intervention, 20 years after the onset of symptoms, the condition can result in an 85% mortality rate. Pulmonary edema develops with sudden changes in flow across the mitral valve, such as the increased flow that occurs in exercise. Atrial dysrhythmias, particularly paroxysmal atrial tachycardia, atrial flutter, and atrial fibrillation, occur with more long-standing disease. Pulmonary hypertension can cause fibrosis of the alveoli and pulmonary capillaries. Recurrent pulmonary emboli, pulmonary infections, infective endocarditis, and systemic embolization are all potential complications.
The predominant cause of mitral stenosis is rheumatic fever. Approximately 40% of individuals with rheumatic heart disease have pure or predominant mitral stenosis. A congenital absence of one of the papillary muscles, resulting in a parachute deformity of the mitral valve, is rare. This deformity is observed almost exclusively in infants and young children. Other uncommon causes of mitral stenosis include malignant carcinoid syndrome, systemic lupus erythematosus, rheumatoid arthritis, thrombus formation, and the mucopolysaccharidoses of the Hunter-Hurley phenotype.
Cardiac congenital valve anomalies can produce mitral stenosis, and there have been reports of families with heritable disease affecting the mitral valve.
Gender, ethnic/racial, and life span considerations
Approximately two-thirds of the patients with mitral stenosis are female. Two-thirds of all women with rheumatic mitral stenosis are younger than age 45. There are no known racial and ethnic considerations for mitral stenosis.
Global health considerations
Rheumatic fever and related mitral valve disease are more common in developing than in developed nations.
Because patients generally have a history of either rheumatic fever or a genetic predisposition to valvular heart disease, ask about specific dates and treatments related to the initial episode of rheumatic fever. Note the use of prophylactic antibiotics against the recurrence of rheumatic fever.
Patients may remain asymptomatic for a period of 10 to 15 years after the diagnosis. Once the valve orifice decreases to less than 2.5 cm2, however, any physiological state that causes an increase in cardiac output (exercise, fever, anxiety, pain, pregnancy) or a decrease in diastolic filling time (tachycardias, atrial fibrillation) may cause the patient to complain of excessive fatigue, malaise, decreased tolerance to exercise, dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, and dry cough.
As the valve orifice becomes increasingly narrowed, symptoms of right-sided heart failure may occur. Inspect the patient for neck vein distention and pitting peripheral edema. Pulmonary edema may also occur and lead to orthopnea, tachypnea, diaphoresis, pallor, cyanosis, and pink frothy sputum. Palpate the patient’s abdomen for hepatomegaly and auscultate the patient’s lungs for crackles.
You may note a normal apical pulse or an irregular rate associated with atrial fibrillation when the heart is auscultated. There are four principal findings: (1) a loud apical first heart sound (closure of the stenotic mitral valve); (2) an opening snap (the snapping of the stenotic mitral valve); (3) a rumbling, apical diastolic low-frequency murmur (blood flowing with difficulty and under increased pressure through the stenotic mitral valve); and (4) an increased pulmonic second sound associated with pulmonary hypertension.
Often, patients have been living with the diagnosis for more than 10 years. The possibility of open heart surgery presents a crisis for patients who fear for their lives. In addition, their symptoms may interfere with activities of daily living. Assess the patient’s degree of anxiety and ability to cope with the disease.
|Test||Normal Result||Abnormality With Condition||Explanation|
|Transesophageal echocardiogram||Normal mitral valve||Stenotic mitral valve, left atrial enlargement||Opening of mitral valve is narrow, which elevates left atrial pressure and leads to left atrial hypertrophy and right ventricular hypertrophy|
|Cardiac catheterization||Normal mitral valve||Stenotic mitral valve; elevation of left atrial pressure, elevation of pulmonary capillary pressures and venous pressures, left atrial enlargement||Same as above|
|Doppler echocardiography||Normal mitral valve||Stenotic mitral valve; left atrial enlargement||Same as above|
Other Tests: Electrocardiogram may show atrial fibrillation, chest radiography, prothrombin time, activated partial thromboplastin time
Primary nursing diagnosis
DiagnosisActivity intolerance related to pulmonary congestion and decreased blood supply to meet the demands of the body
OutcomesEnergy conservation; Coping; Knowledge: Disease process; Mood equilibrium; Symptom severity; Health beliefs: Perceived control; Knowledge: Medication; Treatment regimen
InterventionsEnergy management; Counseling; Exercise promotion; Hope instillation; Security management; Security enhancement; Presence; Medication management; Teaching: Prescribed diet and medications
Planning and implementation
Once symptomatic, a patient usually progresses from mild to total disability in 5 to 10 years. This downhill course can be accelerated by conversion from a normal cardiac rhythm to atrial fibrillation or by pregnancy, bacterial endocarditis, or embolization.
Patients with mitral valve area less than 1.5 cm2 may be considered for percutaneous balloon valvuloplasty if the pulmonary pressure is appropriate and they have reparable valves. The procedure is also used in young patients without calcification, symptomatic pregnant women, and by elderly individuals who are poor candidates for open heart surgery. Definitive therapy for mitral stenosis is surgical replacement of the stenotic valve, particularly when the valve has marked stenosis with an orifice less than 1 cm2. Postoperative anticoagulation is not required. Therefore, even patients with mild symptoms are candidates for surgery. Patients who have more severe, disabling symptoms are more likely to require valve replacement. Either a bioprosthetic or a mechanical valve is used by the surgeon, depending on the patient’s condition and the surgeon’s preference. (See Coronary Artery Disease, p. 282, for collaborative and independent interventions for the patient who is undergoing open heart surgery.)
|Medication or Drug Class||Dosage||Description||Rationale|
|Diuretics||Varies with drug||Thiazides; loop diuretics||Manage fluid overload and congestive symptoms|
|Calcium channel blockers||Varies with drug||Diltiazem||Depresses impulse formation and conduction|
|Coronary vasodilators||Varies with drug||Nitroglycerine, nitroprusside, captopril, enalapril, hydralazine||Decrease preload and afterload; decrease regurgitant blood flow; reduce ventricular size|
|Warfarin||Initially 10–15 mg, then 2–10 mg/day maintenance||Anticoagulant||Prevents thrombi from forming on the synthetic valve|
|Heparin or low-molecular-weight heparin||Initially 80 units/kg IV bolus, followed by an infusion of 18 units/kg; serial monitoring of activated partial thromboplastin to guide future doses||Anticoagulant||Prevents thrombi initially until warfarin therapy is well regulated|
Other Drugs: Inotropic agents (dobutamine [Dobutrex], digoxin) are used to enhance the heart’s pumping ability. If they are present, dysrhythmias are treated with antidysrhythmics, such as propranolol (Inderal), amriodarone, or quinidine. Antibiotics are used prophylactically against bacterial endocarditis and prior to interventional therapies and dental procedures (manipulation of gingival tissue, procedures on the apex of a tooth, or perforation of oral mucosa); common antibiotics are ampicillin, amoxicillin, clindamycin, gentamicin.
Focus on early detection and management of symptoms and the prevention of complications. Interventions depend on the stage of the disease process. If the patient is newly diagnosed, patient teaching becomes important because of the patient’s knowledge deficit. If the patient has severe symptoms that interfere with the ability to perform daily functions, strategies to maintain rest and conserve energy become important. If the patient is a surgical candidate, preoperative and postoperative management are the priority.
During periods of activity intolerance, encourage the patient to maintain bedrest and to allow full assistance with hygiene activities. Provide a bedside commode rather than a bedpan to decrease energy expenditure during voiding. Encourage the patient to keep the head of the bed elevated to at least 30 degrees. Support both arms with pillows to ease breathing and to augment chest excursion. Explore with the patient preferred diversionary activities, such as reading, watching television, needlework, listening to the radio, or quiet visitation with friends and family. Monitor the number of visitors to ensure that the patient is not overfatigued.
Encourage the patient and family to discuss their fears about the progress of the symptoms or the possibility of surgery. Answer questions honestly, provide accurate information, and allow the patient and significant others time to digest information before adding additional content. If the patient needs surgical intervention, evaluate the patient’s home situation to determine if additional home assistance will be needed after discharge.
Evidence-Based Practice and Health Policy
Eleid, M., Nishimura, R., & Sorajja, P. (2012). Impact of left ventricular diastolic dysfunction in patients with symptomatic mitral stenosis. Journal of the American College of Cardiology, 59(13s1), E2036. doi 10.1016/S0735-1097(12)62037-3
- Investigators examined 104 patients with mitral stenosis who underwent percutaneous balloon mitral valvotomy and found that recurrent, severe cardiovascular symptoms were more prevalent in the patients with higher left ventricular end diastolic pressure (LVEDP; ≥ 16 mmHg) compared to patients with LVEDP < 16 mmHg (83% versus 54%) (p = 0.002).
- Thirty-six percent of the patients had an elevated LVEDP prior to the procedure. A history of obesity (p = 0.002) and diabetes (p = 0.02) were significantly associated with increased LVEDP.
- Physical findings of the cardiopulmonary and renal systems: Heart and breath sounds, vital signs, capillary refill, pulmonary artery pressure readings if applicable, intake and output, daily weights
- Presence of complications associated with mitral stenosis: Atrial fibrillation, pulmonary edema, heart failure
- Response to medications used to treat the symptoms and complications that are associated with mitral stenosis
- Tolerance to activity
- Response to surgical intervention: Wound healing, fluid balance, pulmonary artery pressures and cardiac output, urine output, chest tube drainage
Discharge and home healthcare guidelines
Assess the patient’s home environment to determine if additional assistance will be needed after discharge. Be sure the patient understands all medications, including the dosage, route, action, and adverse effects. Instruct the patient to report orthopnea, tachypnea, diaphoresis, frothy sputum, irregular pulse, and chest discomfort.