Aortic Valve Insufficiency


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Related to Aortic Valve Insufficiency: Aortic Incompetence

Aortic Valve Insufficiency

 

Definition

The aortic valve separates the left ventricle of the heart (the heart's largest pumping chamber) from the aorta, the large artery that carries oxygen-rich blood out of the left ventricle to the rest of the body. In aortic valve insufficiency, the aortic valve becomes leaky, causing blood to flow backwards into the left ventricle.
A human heart with a diseased valve that doesn't open and close properly, allowing blood to backflow to the heart.
A human heart with a diseased valve that doesn't open and close properly, allowing blood to backflow to the heart.
(Illustration by Argosy, Inc.)

Description

Aortic valve insufficiency occurs when this valve cannot properly close after blood that is leaving the heart's left ventricle enters the aorta. With each contraction of the heart more and more blood flows back into the left ventricle, causing the ventricle to become overfilled. This larger-than-normal amount of blood that collects in the left ventricle puts pressure on the walls of the heart, causing the heart muscle to increase in thickness (hypertrophy). If this thickening continues, the heart can be permanently damaged.
Aortic valve insufficiency is also know as aortic valve regurgitation because of the abnormal reversed flow of blood leaking through the poorly functioning valve.

Causes and symptoms

The faulty working of the aortic valve can be caused by a birth defect; by abnormal widening of the aorta (which can be caused by very high blood pressure and a variety of other less common conditions); by various diseases that cause large amounts of swelling (inflammation) in different areas of the body, like rheumatic fever; and, although rarely, by the sexually transmitted disease, syphilis.
About 75% of people with aortic valve insufficiency are men. Rheumatic (inflammatory) diseases have been the main cause of this condition in both men and women.
Aortic valve insufficiency can remain unnoticed for 10 to 15 years. In cases of severe insufficiency a person may notice a variety of symptoms, including an uncomfortable pounding of the heart when lying down, a very rapid or hard heart beat (palpitations), shortness of breath, chest pain, and if untreated for very long times, swelling of the liver, ankles, and belly.

Diagnosis

A poorly functioning or insufficient aortic valve can be identified when a doctor listens to the heart during a physical examination. A chest x ray, an electrocardiogram (ECG, an electrical printout of the heart beats), as well as an echocardiogram (a test that uses sound waves to create an image of the heart and its valves), can further evaluate or confirm the condition.

Treatment

Aortic insufficiency is usually corrected by having the defective valve surgically replaced. However, such an operation is done in severe cases. Before the condition worsens, certain drugs can be used to help manage this condition.
Drugs that remove water from the body, drugs that lower blood pressure, and drugs that help the heart beat more effectively can each be used for this condition. Reducing the amount of salt in the diet also helps lower the amount of fluid the body holds and can help the heart to work more efficiently as well.
In cases of a severely malfunctioning valve that has been untreated for a long time, surgery is the treatment of choice, especially if the heart is not functioning normally. Human heart valves can be replaced with man-made valves or with valves taken from pig hearts.

Prognosis

Although drug treatment can help put off the need for surgical valve replacement, it is important to replace the faulty valve before the heart muscle itself is damaged beyond recovery.

Resources

Periodicals

Condos Jr., William R. "Decade-old Heart Drug May Have a New Use." San Diego Business Journal 18 (21 July 1997): 24.

Organizations

American Heart Association. 7320 Greenville Ave. Dallas, TX 75231. (214) 373-6300. http://www.americanheart.org.
National Heart, Lung and Blood Institute. P.O. Box 30105, Bethesda, MD 20824-0105. (301) 251-1222. http://www.nhlbi.nih.gov.

Key terms

Rheumatic fever — A disease believed to be caused by a bacterium named group A streptococcus. This bacterium causes a sore "strep throat" and can also result in fever. Infection by this bacterium can also damage the heart and its valves, but how this takes place is not clearly understood.

insufficiency

(in?su-fish'en-se) [ L. insufficientia, insufficiency]
Inadequacy for a specific purpose.

active insufficiency

Loss of the ability to generate muscle tension because of muscle shortening.
See: Active Insufficiency

acute adrenocortical insufficiency

Sudden deficiency of adrenocortical hormone brought on by sepsis, surgery, or Waterhouse-Friderichsen syndrome. A frequent cause is sudden withdrawal of adrenal corticosteroids from patients with adrenal atrophy secondary to chronic steroid administration.
Synonym: addisonian crisis; adrenal crisis

adrenal insufficiency

Abnormally low production of cortisol. Primary adrenal insufficiency results from inadequate cortisol production by the adrenal glands, as in Addison disease. Secondary adrenal insufficiency results from a decrease in the production of adrenocorticotropic hormone (ACTH) or its release from the pituitary gland.

aortic insufficiency

Abbreviation: AI
An imperfect closure of the aortic semilunar valve at the junction of the left ventricle and the aorta, due to distortion of the valve leaflets or dilation of the aortic annulus. This causes blood that has been ejected into the aorta to fall back into the left ventricle. It may produce volume overload of the ventricle, leading to left ventricular dilation and hypertrophy, and congestive heart failure. Stroke volume and ejection fraction (EF) fall. Synonym: aortic incompetence; aortic regurgitation; aortic valve insufficiency

Chronic aortic insufficiency produces a gradual volume overload of the heart and eventual congestive heart failure. It may occur in patients with poorly controlled hypertension, tertiary syphilis, Marfan's disease, or other disorders that affect aortic valve competence. Management often includes antihypertensive vasodilators such as nifedipine. If congestive heart failure becomes severe enough, valve replacement may be recommended for patients who are good operative candidates. Surgery usually is recommended to be done before EF falls below 55%.

Symptoms

Chronic AI may be asymptomatic until heart failure (HF) occurs. With HF, patients often report difficulty breathing, e.g., during exercise or sleep, and lower extremity swelling. Patients may occasionally report palpitations or a subjective awareness of their heart beating.

Physical Findings

The murmur of AI occurs in diastole, is high-pitched (best heard using the diaphragm of the stethoscope), and is usually described as “blowing” and “decrescendo.” It is best heard at the left second to fourth intercostal spaces, radiating to the apex and sometimes the right sternal border, after the patient exhales and sits leaning forward, holding his or her breath. Patients with AI often have a widened pulse pressure with a waterhammer pulse and may have head bobbing, bobbing of the uvula, or visible movement of blood under the nails when the tips of the nails are gently compressed (Quincke pulse). The patient may experience dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and fatigue.

Patient care

A history of related cardiac illnesses and symptoms is obtained. Fever and other signs of infection are noted. Vital signs, weight, and fluid intake and output are monitored for indications of fluid overload. Activity tolerance and degree of fatigue are assessed regularly, and the patient is taught to intersperse periods of activity with rest.

Desired outcomes include adequate cardiopulmonary tissue perfusion and cardiac output, reduced fatigue with exertion, and ability to manage the treatment regimen.

aortic valve insufficiency

Aortic insufficiency.

cardiac insufficiency

Heart failure.

coronary insufficiency

Obstruction to the flow of blood through the coronary arteries, resulting in an inadequate supply of blood relative to the metabolic demands of the heart muscle.
See: angina pectoris; coronary artery disease

gastric insufficiency

Inability of the stomach to empty itself.

hepatic insufficiency

Inability of the liver to produce albumin, bile, or proteins, or to detoxify xenobiotics that are taken up by the gastrointestinal tract.

ileocecal insufficiency

Ileocecal incompetence.

ill-sustained insufficiency

Difficulty in maintaining visual accommodation, esp. after much reading or close work.
Synonym: ill-sustained accommadation

mitral insufficiency

Mitral regurgitation.

muscular insufficiency

A condition in which a muscle is unable to exert its normal force and bring about normal movement of the part to which it is attached.

insufficiency of ocular muscles

Absence of dynamic equilibrium of ocular muscles.

myocardial insufficiency

Inability of the heart to perform its usual function, eventually resulting in cardiac failure.

passive insufficiency

A restriction in the range of motion of multijoint muscles such as the extrinsic finger flexors and extensors, the hamstrings, and the quadriceps caused by inadequate extensibility of antagonist muscles, muscle groups or fascia. This limitation is a normal property of multijoint muscles and helps optimize the relation between muscle length and tension.
See: Passive Insufficiency

primary adrenal insufficiency

Addison disease.

pulmonary valvular insufficiency

Imperfect closure of the pulmonary semilunar valve at the junction of the right ventricle and the pulmonary artery. The clinical consequences may include right ventricular failure.

renal insufficiency

A less-preferred term for chronic kidney disease.
See: chronic kidney disease

respiratory insufficiency

Inadequate oxygen intake or carbon dioxide removal associated with abnormal breathing and signs and symptoms of distress.

secondary adrenal insufficiency

Insufficient stimulation of the adrenal glands caused by failure of the pituitary gland to secrete adrenocorticotropic hormone. In this disorder, cortisol levels are reduced, but aldosterone secretion, which is governed by the renin-angiotensin-aldosterone system, is preserved. This differs from primary adrenal insufficiency or Addison disease in which the adrenal glands secrete neither cortisol nor aldosterone.

tertiary adrenal insufficiency

Inadequate stimulation of the adrenal glands that results from a failure of the hypothalamus to secrete corticotropic-releasing hormone.

thyroid insufficiency

Hypothyroidism.

uteroplacental insufficiency

Inadequate blood flow through the placental intervillous spaces to enable sufficient transmission of nutrients, oxygen, and fetal wastes. It may be caused by diminished maternal cardiac output due to anemia, heart disease, regional anesthesia, or supine hypotension; vasoconstriction due to chronic or pregnancy-related hypertension or uterine overstimulation; vasospasm due to pregnancy-induced hypertension; vascular sclerosis due to maternal diabetes or collagen disease; or intrauterine infection. It increases the risk for intrauterine growth retardation.

valvular insufficiency

Valvular incompetence.

velopharyngeal insufficiency

Failure of the palatal sphincter to close, with inadequate separation of the nasopharynx from the oropharynx. This may result in snoring, nasal speech, or inhalation of food into the nasal passages
Synonym: velopharygeal incompetence See: cleft palate

venous insufficiency

A failure of the valves of the veins to function, which interferes with venous return to the heart, and may produce edema.

Aortic Valve Insufficiency

DRG Category:307
Mean LOS:3.3 days
Description:MEDICAL: Cardiac Congenital and Valvular Disorders without Major CC

Aortic valve insufficiency (AI) is the incomplete closure of the aortic valve leaflets, which allows blood to regurgitate backward from the aorta into the left ventricle. The retrograde blood flow occurs during ventricular diastole when ventricular pressure is low and aortic pressure is high. The backflow of blood into the ventricle decreases forward flow in the aorta and increases left ventricular volume and pressure. In compensation, the left ventricle dilates and hypertrophies to accommodate the increased blood volume. Eventually, the increase in left ventricular pressure is reflected backward into the left atrium and pulmonary circulation. Risk of premature death from AI, as well as complications and the chronic need for medication because of congenital heart disease, is approximately 50%.

Most patients with AI experience left ventricular failure. If heart failure is serious, the patient may develop pulmonary edema. If the patient is overtaxed by an infection, fever, or cardiac dysrhythmia, myocardial ischemia may also occur.

Causes

AI may result either from an abnormality of the aortic valve or from dilation and distortion of the aortic root. AI can be congenital or acquired. Congenital abnormalities are associated ventricular septal defect, bicuspid aortic valve, subvalvular aortic stenosis, dysplasia of valve cusps, or the absence of two or three aortic valve leaflets. Acquired AI results from conditions such as endocarditis, trauma, systemic diseases such as rheumatic fever or systemic lupus erythematosus, and connective tissue syndromes.

Dilation or distortion of the aortic root may be due to systemic hypertension, aortic dissection, syphilis, Marfan’s syndrome, and ankylosing spondylitis. Rheumatic heart disease and endocarditis cause the valve cusps to become thickened and retracted, whereas an aortic aneurysm causes dilation of the annulus (the valve ring that attaches to the leaflets). Chronic high blood pressure causes an increased pressure on the aortic valve, which may weaken the cusps. All of these conditions inhibit the valve leaflets from closing tightly, thus allowing backflow of blood from the high-pressure aorta.

Genetic considerations

AI can occur as a feature of several genetic diseases, including Marfan’s syndrome, Turner’s syndrome, and velocardiofacial syndrome. Alternations in the aortic valve structure, such as bicuspid aortic valve, have been shown to be heritable. Mutations in the NOTCH1 gene can lead to aortic valve calcification, among other congenital aortic valve defects, in an autosomal dominant inheritance pattern.

Gender, ethnic/racial, and life span considerations

Symptoms do not usually occur until age 40 to 50. AI is more common in males unless it is associated with mitral valve disease, when it is then more common in women. Mild aortic regurgitation is probably quite common in the elderly but is usually overlooked. Ethnicity and race have no known effect on the risk of AI.

Global health considerations

Rheumatic heart disease and subsequent valvular disease is a continuing problem in developing nations, where up to 60% of all admissions for cardiovascular illnesses are related to the condition. Prevalence may be as low as 1 per 100,000 children in Costa Rica to as high as 150 per 100,000 children in China. Areas of particular concern are Southeastern Asia, Central America, North Africa, and the Middle East.

Assessment

History

A history of rheumatic fever suggests possible cardiac valvular malfunction; however, many patients who have had rheumatic fever do not remember having the condition. The most common symptom of AI is labored breathing on exertion, which may be present for many years before progressive symptoms develop. Angina with exertion, orthopnea, and paroxysmal nocturnal dyspnea are also principal complaints. Patients with severe AI often complain of an uncomfortable awareness of their heartbeat (palpitations), especially when lying down.

Physical examination

Inspection of the thoracic wall may reveal a thrusting apical pulsation. Palpation of the precordium reveals the apical pulse to be bounding and displaced to the left. Auscultation of heart sounds reveals the classic decrescendo diastolic murmur. The duration of the murmur correlates with the severity of the regurgitation. Auscultation of breath sounds may reveal fine crackles (rales) if pulmonary congestion is present from left-sided heart failure. The pulmonary congestion will vary with the amount of exertion, the degree of recumbency, and the severity of regurgitation. Assessment of vital signs reveals a widened pulse pressure caused by the low diastolic blood pressure (often close to 40 mm Hg). The heart rate may be elevated in the body’s attempt to increase the cardiac output and decrease the diastolic period of backflow.

Psychosocial

The symptoms of AI usually develop gradually. Most people have already made adjustments in their lifestyle to adapt, not seeking treatment until the symptoms become debilitating. Assess what the patient has already done to cope with this condition.

Diagnostic highlights

TestNormal ResultAbnormality With ConditionExplanation
Cardiac catheterization and aortic angiographyNormal aortic valveDiastolic regurgitant flow from the aorta into the left ventricle; increased left ventricular end-diastolic volume/pressureAortic valve is incompetent, and during diastolic phase, blood flows backward into the left ventricle
Transthoracic echocardiographyNormal aortic valveIncompetent aortic valve, thickening and flail of valve structuresAortic valve is incompetent, and during diastolic phase, blood flows backward into the left ventricle

Other Tests: Echocardiography to assess aortic valve’s structure and mobility electrocardiogram; chest radiography, magnetic resonance imaging, color-flow Doppler, pulse-flow Doppler, continuous-flow Doppler, computed tomography

Primary nursing diagnosis

Diagnosis

Activity intolerance related to imbalance between oxygen supply and demand

Outcomes

Endurance; Energy conservation; Self-care; Ambulation: Walking; Circulation status; Cardiac pump effectiveness; Rest; Respiratory status; Symptom severity; Nutritional status: Energy

Interventions

Activity therapy; Energy management; Circulatory care; Exercise therapy: ambulation; Oxygen therapy; Self-care assistance; Nutrition management

Planning and implementation

Collaborative

medical.
Medical management focuses initially on treating the underlying cause, such as endocarditis or syphilis. Patients are encouraged to limit strenuous physical activity. Fluid restrictions and diuretics may be ordered to reduce pulmonary congestion. Supplemental oxygenation will enhance oxygen levels in the blood to decrease labored breathing and chest pain.

surgical.
Most patients can be stabilized with medical treatment, but early elective valve surgery should be considered because the outlook for medically treated symptomatic disease is poor. Surgical repair or replacement is the most common treatment of AI.

The incompetent valve can be repaired (valve-sparing techniques) or replaced with a synthetic or biological valve, such as a pig valve. The choice of valve type is based on the patient’s age and potential for clotting problems. The biological valve usually shows structural deterioration after 6 to 10 years and needs to be replaced. The synthetic valve is more durable but also more prone to thrombi formations.

Pharmacologic highlights

Medication or Drug ClassDosageDescriptionRationale
Digoxin0.25 mg PO qdCardiotonicIncreases force of contraction in people with left ventricular dysfunction
Vasodilators such as nifedipine, hydralazine, prazosin, nitroprussideNifedipine, 10–30 mg tid PO or SLCalcium channel blocker; systemic vasodilatorsDecrease afterload (pressure that the left ventricle has to pump against) and decreases regurgitant blood flow
DiureticsVaries with drugThiazides; loop diureticsEnhance pumping ability of the heart

Other Medications: If the incompetent valve is replaced surgically with a synthetic valve, patients are prescribed long-term anticoagulation therapy such as warfarin (Coumadin) to prevent thrombi from forming on the synthetic valve. Initially, heparin is given along with the warfarin, and the prothrombin time (PT) is monitored. As the PT value becomes therapeutic, the heparin is discontinued. The use of beta blockers is controversial and under investigation. If the patient is critically ill prior to surgery, he or she may receive a positive inotrope, such as dopamine or dobutamine, and a vasodilator, such as nitroprusside.

Independent

Physical and psychological rest decreases cardiac workload, which reduces the metabolic demands on the myocardium. Physical rest is enhanced by providing assistance with activities of daily living and encouraging activity restrictions. Most patients with advanced AI are placed on activity restrictions to decrease cardiac workload. If the patient is on bedrest, advise her or him to use the bedside commode, because research has shown it creates less workload for the heart than using the bedpan. If the patient can tolerate some activities, those that increase isometric work, such as lifting heavy objects, are more detrimental than activities such as walking or swimming.

Encourage the patient to avoid sudden changes in position to minimize increased cardiac demand. If the patient is hospitalized, instruct the patient to sit on the edge of the bed before standing. If pulmonary congestion is present, elevate head of bed slightly to enhance respiration.

Reducing psychological stress is a challenge. Approach the patient and family in a calm, relaxed manner. Decrease the fear of the unknown by providing explanations and current information and encouraging questions. To help the patient maintain or reestablish a sense of control, permit the patient to participate in decisions about aspects of care within his or her knowledge. If the patient decides to have valve surgery, offer to let her or him speak with someone who has already had the surgery. Seeing and talking with someone who has undergone surgery and lives with a replacement valve is usually very therapeutic.

Evidence-Based Practice and Health Policy

Lowenthal, A., Tacy, T.A., Behzadian, F., & Punn, R. (2013). Echocardiographic predictors of early postsurgical myocardial dysfunction in pediatric patients with aortic valve insufficiency. Pediatric Cardiology, 34(6), 1335–1343.

  • Investigators explored predictors of early postsurgical myocardial dysfunction in a sample of 40 pediatric patients undergoing surgical repair of moderate to severe aortic valve insufficiency.
  • In this sample, preoperative left-ventricular global longitudinal strain (GLS) values < 15.4 and strain rate (GLSr) values < −0.79/second predicted postoperative myocardial dysfunction (p < 0.0001).
  • Preoperative GLS and GLSr values may help identify higher postoperative risks in patients with aortic valve insufficiency and should be used to inform planning during the immediate postoperative period.

Documentation guidelines

  • Physical findings: Diastolic murmur, bounding apical pulse, rales in the lungs, presence or absence of pain, quality of pulses
  • Response to diuretics, cardiotonics, vasodilators, and inotropic agents
  • Reaction to activity restrictions, fluid restrictions, and cardiac diagnosis
  • Presence of complications: Chest pain, bleeding, fainting

Discharge and home healthcare guidelines

medications.
Be sure the patient understands all medications, including the dose, route, action, adverse effects, and need for routine laboratory monitoring for anticoagulants.

complications of anticoagulants.
Explain the need to avoid activities that may predispose the patient to excessive bleeding. Teach the patient to hold pressure on bleeding sites to assist in clotting. Remind the patient to notify health care providers of anticoagulant use before procedures. Identify foods high in vitamin K (fats, fish meal, grains), which should be limited so that the effect of anticoagulants is not reversed.

teaching.
Instruct the patient to report the recurrence or escalation of signs and symptoms of AI, which could indicate that the medical therapy needs readjusting or the replaced valve is malfunctioning. Patients with synthetic valves may hear an audible click like a ticking watch from the valve closure.

prevention of bacterial endocarditis.
Patients who have had surgery are susceptible to bacterial endocarditis, which will cause scarring or destruction of the heart valves. Bacterial endocarditis may result from dental work, surgeries, and invasive procedures, so people who have repaired or replaced heart valves should be given antibiotics before and after these treatments.