stenosal

marked by abnormal narrowing or constriction.

The constriction or narrowing of a passage or orifice. stenosedstenotic (ste-nost', ste-nozd', ) (ste-not'ik), adjective

Etiology

Stenosis may result from embryonic maldevelopment, hypertrophy and thickening of a sphincter muscle, inflammatory disorders, or excessive development of fibrous tissue. It may involve almost any tube or duct.

Stenosis of blood flow from the left ventricle to the aorta due to aortic valve disease or obstructions just above or below the valve. The stenosis may be congenital or secondary to diseases of adolescence or adulthood, e.g., rheumatic fever or fibrocalcific degeneration of the valve. It is the most common cardiac valve dysfunction in the U.S. Synonym: aortostenosis

Symptoms

Many patients with mild or moderate aortic stenosis, e.g., with a valve area that is more than 1 cm² or a valve gradient that is less than 50 mm Hg, have no symptoms and are unaware of their condition. A heart murmur is usually heard on physical examination of the patient. This murmur is best heard at the right second intercostal space during systole. Palpation of the arteries in severe aortic stenosis may reveal a delayed and weakened pulse, e.g., at the carotids. The heart's apical impulse may be laterally and inferiorly displaced as a result of left ventricular hypertrophy. Alarming symptoms include anginal chest pain, syncope, and dyspnea on exertion. When these occur, surgery to repair or replace the diseased valve are necessary.

Physical Findings

Transthoracic echocardiography (TTE) diagnoses aortic stenosis and helps to evaluate its severity, determine left ventricular size and function, and detect other valvular disease.

Treatment

If the aortic valve area is significantly narrowed, i.e., < 0.8 cm², or if the patient has experienced symptoms of heart failure or syncope, percutaneous balloon aortic valvuloplasty or aortic valve replacement may be necessary.

Patient care

A history of related cardiac disorders is obtained. Cardiopulmonary function is assessed regularly by monitoring vital signs and weight, intake, and output for signs of fluid overload. The patient is monitored for chest pain, which may indicate cardiac ischemia, and the electrocardiogram is evaluated for ischemic changes. Activity tolerance and fatigue are assessed.

After cardiac catheterization, the insertion site is checked according to protocol (often every 15 min for 6 hr) for signs of bleeding; the patient is assessed for chest pain, and vital signs, heart rhythm, and peripheral pulses distal to the insertion site are monitored. Problems are reported to the cardiologist.

Desired outcomes for all aortic valve surgeries include adequate cardiopulmonary tissue perfusion and cardiac output, reduced fatigue with exertion, absence of fluid volume excess, and ability to manage the treatment regimen. Patients with aortic stenosis (with or without surgical repair) require prophylactic antibiotics before invasive procedures (including dental extractions, cleanings) because of the risk they pose for bacteremia and infective endocarditis.

Stenosis due to a contracted scar.

A physical obstruction to the flow of blood through the epicardial arteries, usually due to atherosclerotic plaque.

Stenosis of the spinal canal due to degenerative or traumatic changes at the level of the lumbar vertebrae. This condition causes back pain, often associated with pain that radiates into the legs, esp. when the patient is standing. Sitting often relieves the pain. The diagnosis is performed by spinal imaging, e.g., computed tomography or magnetic resonance imaging scanning. Treatments include physical therapy, braces, analgesic agents, and spinal surgery.

Stenosis of the mitral valve orifice with obstruction of blood flow from the left atrium to the left ventricle. In most adults, previous bouts of rheumatic carditis are responsible for the lesion. Less often, MS may be present at birth (Lutembacher's disease), or it may develop as the mitral valve calcifies during aging.

The abnormality of the valve may predispose patients to infective endocarditis; to left atrial enlargement and atrial arrhythmias; or to left ventricular failure.

Stenosis of the opening into the pulmonary artery from the right cardiac ventricle.

Stenosis of the pyloric orifice. In infants, excessive thickening of the pyloric sphincter or hypertrophy and hyperplasia of the mucosa and submucosa of the pylorus are usually responsible.

Treatment

In infants, treatment may involve open or laparoscopic division of the muscles of the pylorus. Infantile pyloric stenosis is usually diagnosed in the first 6 months of life when babies have trouble with vomiting after eating, sometimes with projectile vomiting and consequent dehydration. The disease occurs in 2 to 3 infants per 1000 births and is more common in boys than girls. In adults, endoscopic stents may be placed to open malignant obstructions.

Stenosis in one or both arteries that supply the kidneys; a relatively uncommon cause of hypertension. In young women the cause is usually fibromuscular dysplasia of one or both arteries. In older people the cause is usually atherosclerosis.

Treatment

Patients may be treated medically with standard antihypertensive drugs, or, in some cases, with renal artery angioplasty or bypass surgery.

See: illustration

A congenital stenosis of the aortic tract below the aortic valves. See: hypertrophic cardiomyopathy

Stenosis of the opening to the tricuspid valve.