Aortic Valve Disease
Aortic valve disease may be caused by aortic stenosis, aortic insufficiency (aortic regurgitation), or a combination of both[1]. The pathology can develop over many years, and symptoms may not appear until the condition is severe. At this stage, morbidity and mortality associated with aortic valve disease are high[2].
Aortic stenosis is the most common valvular heart disease and describes narrowing of the opening of the aortic valve between the aorta and the left ventricle[3].Aortic insufficiency, also known as aortic regurgitation or aortic valve incompetence, is a valvular disorder in which the aortic valve leaks during diastole, causing blood to flow backward from the aorta into the left ventricle[4].
Structure and Function of the Aortic Valve
Heart valves are structures that function as one-way valves. They allow blood to flow from one chamber or vessel to another and then close to prevent backward flow. The aortic valve consists of three semilunar pockets of delicate tissue, referred to as cusps. When the aortic valve is closed, the cusps align precisely and separate the main pumping chamber of the heart (the left ventricle) from the major artery (the aorta) that supplies blood to the body. During systole, when the left ventricle contracts and pumps blood, the aortic valve opens widely and blood flows freely from the left ventricle into the aorta. When the left ventricle subsequently relaxes during diastole, the aortic valve closes completely so that blood remains in the aorta. During diastole, blood flows into the left ventricle from the lungs through the left atrium and across the mitral valve, filling the ventricle for the next contraction[1].
Etiology
There are two common causes of aortic stenosis (AS): calcific age-related aortic stenosis and a congenital bicuspid aortic valve. More rarely, aortic stenosis and/or aortic regurgitation may result from rheumatic heart disease.
Calcific aortic stenosis is the most common cause and is thought to develop through progressive endothelial injury over many years. The causes of chronic aortic regurgitation include many of the same pathologies that commonly cause aortic stenosis[2].
Epidemiology
Aortic stenosis is the most common valvular heart disease. The condition has a male predominance of approximately 4:1, and the prevalence of degenerative aortic valve disease, the most common cause of aortic stenosis, increases with age[3]. It is more prevalent in older populations. According to a prospective population-based study, the prevalence of aortic stenosis was 0.2% in the fifth decade of life, 1.3% in the sixth, 3.9% in the seventh and 9.8% in the eighth decade[2].
Aortic regurgitation occurs slightly more often in men, and prevalence gradually increases after the age of 50[4]. An estimated prevalence of 4.9% has been reported, increasing with age into the sixth decade before beginning to decline[2].
Signs and Symptoms
A major sign of heart valve disease can be an abnormal heart sound, known as a heart murmur. Heart valve disease often worsens over time, so signs and symptoms may develop years after a murmur is first detected. Many people with heart valve disease have no symptoms until middle or older age[5].
Chronic aortic regurgitation and late-stage aortic stenosis generally produce two main categories of symptoms: heart failure and reduced coronary and systemic perfusion. As pressure in the left ventricle increases, patients may develop congestive heart failure and report swelling of the feet, shortness of breath, orthopnea, paroxysmal nocturnal dyspnea and exertional dyspnea. Patients may say they need extra pillows at night because lying flat causes breathlessness. They may also report reduced exercise tolerance and may feel dizzy after walking several blocks. In severe cases, patients may present with syncope or anginal symptoms[2].
Treatment
There is no medical treatment that has been shown to delay progression of asymptomatic aortic valve disease. Management focuses on optimizing other cardiovascular comorbidities, such as hypertension, coronary artery disease, left-ventricular dysfunction and atrial fibrillation, together with careful monitoring for symptom development and disease progression.
Management of patients with aortic valve disease requires a multidisciplinary team, including clinicians and specialists, healthcare professionals with relevant expertise, specially trained nurses and pharmacists working across disciplines to achieve optimal patient outcomes[2].
Lifestyle changes and medication can often manage symptoms successfully and delay problems for many years. Ultimately, however, surgery may be required to repair or replace a defective heart valve.
Treatment goals for heart valve disease may include:
Medication
Repair or replacement of defective valves
Heart-healthy lifestyle changes to manage other related cardiovascular problems.
Valve Disease and Valve Surgery
The decision to repair or replace a heart valve depends on several factors, including:
The severity of the valve disease.
Whether the patient requires cardiac surgery for another condition, such as coronary artery bypass surgery. Bypass surgery and valve surgery may be performed during the same procedure.
Age and general health.
When possible, heart-valve repair is generally preferred over valve replacement. Valve repair preserves the strength and function of the heart muscle. People who undergo valve repair may also have a lower risk of infective endocarditis after surgery and may not require lifelong anticoagulant medication solely because of a mechanical prosthetic valve.
However, heart-valve repair can be technically more difficult than valve replacement. Aortic valves often require replacement[5].
Prognosis
Prognosis is largely determined by the timing of symptom onset. Asymptomatic patients who remain free of symptoms generally have a longer life expectancy. The prognosis for patients with severe symptomatic aortic valve disease who do not undergo valve replacement is poor, with reported three-year survival of approximately 40–60%, whereas patients who underwent valve replacement had survival rates of approximately 80–90%[2].
Complications
Congestive heart failure
Sudden cardiac death due to arrhythmia
Calcific cerebral emboli
Heyde syndrome[3]
Physiotherapy
A multidisciplinary rehabilitation program should be available to patients undergoing valve surgery so that an exercise program can begin while they are still in hospital. Rehabilitation specialists working in acute care should collaborate with the medical team to evaluate the risks and benefits of physiotherapy intervention and to support institutional guidelines, procedures and clinical decision-making regarding the appropriate intensity of physiotherapy in the acute postoperative period.
Outcome Measures:
Whenever possible, the physiotherapist should perform a comprehensive assessment using appropriate tests and outcome measures, such as the 30-Second Chair Stand Test, FIM scores and the 10-Meter Walk Test (10MWT)[6].
Sources:
Nishimura RA. Aortic valve disease. Circulation. 2002 Aug 13;106(7):770-2.: https://www.ahajournals.org/doi/full/10.1161/01.cir.0000027621.26167.5e
Wenn P, Zeltser R. Aortic Valve Disease. StatPearls [Internet]. 2020 Mar 24.: https://www.ncbi.nlm.nih.gov/books/NBK542205/
Radiopaedia Aortic valve stenosis : https://radiopaedia.org/articles/aortic-valve-stenosis?lang=gb
Radiopaedia Aortic valve regurgitation : https://radiopaedia.org/articles/aortic-valve-regurgitation?lang=gb
NIH Heart Valve Disease : https://www.nhlbi.nih.gov/health-topics/heart-valve-disease
Fernandez N, Blackwood J. Acute care physical therapy management of a 69-year-old female following re-operative aortic valve replacement and tricuspid valve repair: A case report.:https://www.oatext.com/acute-care-physical-therapy-management-of-a-69-year-old-female-following-re-operative-aortic-valve-replacement-and-tricuspid-valve-repair-a-case-report.php
