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.
Nursing care plan assessment and physical examination
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 distension 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.
Nursing care plan primary nursing diagnosis: Activity intolerance related to pulmonary congestion and decreased blood supply to meet the demands of the body.
Nursing care plan intervention and treatment plan
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. 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. Percutaneous valvuloplasty may be used in young patients without calcification, by symptomatic pregnant women, and by elderly individuals who are poor risks for open heart surgery.
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.
Nursing care plan discharge and home health care 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.