Valvular heart disease is characterized by a defect or deterioration of one of the valves. Furthermore, the damage to the valve can cause stenosis or regurgitation, and both can occur in the same valve. Each valvular pathology has its own profile of etiology, hemodynamic changes, presentation, treatment, and prognosis.
The presentation of the patient depends on the present valvular disease(s).
The physical exam findings include the hallmark feature, which is the crescendo-decrescendo ejection murmur typically auscultated at both the right and left upper sternal border in a sitting patient that is tilting forward.
Severe cases may exhibit a palpable apical S4 accompanied by a systolic thrill . Furthermore, the pulse in these patients is characterized by the pulsus parvus pattern.
In acute cases, the clinical picture is that of heart failure as well as cardiogenic shock. The exam reveals hypotension, tachycardia, S1 is not present but S3 is commonly heard. The Austin Flint murmur is frequently heard.
The majority of patients do not exhibit symptoms until atrial fibrillation or pregnancy occurs. The clinical presentation resembles the features of heart failure and usually manifests at 15 to 40 years post-rheumatic fever. This may appear in children in the developing world due to under-treatment. Also, symptoms depict the severity of the disease.
The physical assessment reflects a crescendo-crescendo rumbling diastolic murmur and a loud S1. Also, the S1 and S2 are palpable. Note that jugular venous distention is present in cases with pulmonary hypertension.
The symptoms of this valvular abnormality are those of congestive heart failure.
Auscultation is notable for a holosystolic murmur, which can radiate to the upper sternal borders, axilla, or the subscapular area. Valsalva, sitting, or standing makes the murmur more audible.
Furthermore, S1 is soft and S2 may exhibit a wide split. S3 is suggestive of severe MR although it is not always associated with cardiac failure .
Many patients with prolapse are asymptomatic. In others, there are nonspecific symptoms such as angina, dyspnea, dizziness, palpitations, presyncope, headaches and anxiety. Additionally, approximately a third of the cases experience palpitations following emotional stress.
Auscultation demonstrates a midsystolic click when the patient performs the Valsalva maneuver, sits, or stands.
Typically, patients do not present with symptoms in childhood or adulthood. In fact, the majority of adults do not have manifestations. The presentation mimics the AS picture, ie the SAD triad.
The cardiac exam reveals a harsh crescendo-decrescendo ejection murmur at the 2nd or 4th left sternal border. Additionally, S1 is normal and the S2 split is widened.
Most patients do not present with symptoms, lthough a few exhibit signs of RV impairment and heart failure.
The associated murmur is a high-pitched, early diastolic decrescendo murmur.
If present, the murmur is holosystolic, typically auscultated at the middle or lower left sternal borders in the upright or standing positions.
This manifests with neck discomfort, fatigue, cold skin, as well as right upper quadrant discomfort.
The physical exam features a flickering wave, and possibly jugular venous distention that increases with inspiration, otherwise known as Kussmaul sign.
The uncommon murmur is a soft opening snap and mid-diastolic rumble. It becomes louder and longer with any physical activity that leads to an increase in venous return. In contrast, the opposite occurs with Valsalva and standing.
Evaluation of the patient includes the assessment of symptoms, personal and family history, the physical exam with cardiovascular focus, and echocardiography.
Echocardiology will reveal details about the valvular anatomy, function, blood flow, and transvalvular pressure gradient. It also provides measurements of the cardiac chambers and overall cardiac performance.
Chest radiography depicts the heart size, changes in the chambers, edema, and underlying lung diseases.
The electrocardiogram (EKG) demonstrates the rate and rhythm and will identify arrhythmias, ischemia, and hypertrophy.
The therapeutic approach is decided upon by a multidisciplinary team composed of cardiologists, cardiovascular surgeons, and other specialists who will collectively select the best intervention for the particular patient.
Asymptomatic patients should undergo periodic evaluation and echocardiography to assess timing for valvular replacement. The surgery is beneficial in symptomatic patients and those who demonstrate particular findings on an echocardiographic assessment.
In asymptomatic patients, valvular replacement is advised for those with one of the following: 1) left ventricular ejection fraction below 50%, 2) patients with moderate or severe stenosis undergoing heart surgery for different reasons, and 3) severe cases in good surgical candidates.
If the aortic root dilatation contributes to the pathogenesis of AR in a hypertensive patient, angiotensin-receptor blockers may be beneficial .
Surgical intervention is warranted for severe regurgitation with an ejection fraction below 50%.
Asymptomatic individuals require prophylaxis against the recurrence of rheumatic fever .
Patients with mild symptoms may benefit from diuretics. When the patient exhibits tachycardia or atrial fibrillation, then beta blockers or calcium channel blockers are useful. Additionally, thromboembolism prophylaxis with anticoagulants should be used in those with atrial fibrillation or embolism.
Percutaneous balloon commissurotomy is the preferred intervention for younger individuals and in those where stenosis is not associated with severe MR, significantly calcified commissures, subvalvular deformities, or thrombi in the left atria. In fact, the latter three phenomena may benefit from surgical commissurotomy.
Repair is indicated for patients with 1) moderate to severe symptoms, 2) ejection fraction below 60% or 3) an end systolic dimension that nears 45mm.
Repair of the mitral valve is correlated to a lower surgical fatality rate and has better outcomes than valvular replacement.
No therapy is indicated for prolapse.
Balloon valvuloplasty is warranted for a peak gradient greater than 40 to 50 mm Hg.
The etiology should be treated.
Severe regurgitation necessitates surgery at the onset of symptoms or in patients with worsening right ventricular impairment. The procedures are valvular repair, replacement or annuloplasty.
Severe stenosis should be treated surgically in patients that are symptomatic or undergoing heart surgery for different reasons. One procedure is percutaneous balloon tricuspid commissurotomy.
The prognosis of valvular disease correlates with the particular abnormality and the degree of severity.
Severe AS is associated with mortality and almost half of all deaths are sudden. In fact, in asymptomatic individuals with severe disease, it is expected that 3% to 6% will manifest with symptoms or LV dysfunction annually. Therefore, these patients should undergo surveillance.
In mild to moderate disease, the 10 years survival rate is 80% to 95%. Moreover, severe cases are correlated with very poor outcomes.
This is a progressive disease and is life-threatening in patients with atrial fibrillation and pulmonary hypertension. Mortality does occur and is secondary to heart failure and emboli in the lungs or cerebrovasculature.
This benign disease progresses to regurgitation in the presence of myxomatous degeneration.
The outcomes are good without treatment but become better with intervention.
Severe regurgitation of the tricuspid valve ultimately leads to RV decompensation, which is associated with poor prognosis.
The causes of each disease are explained below.
Aortic Stenosis (AS)
The etiology of AS depends on the age group. In the elderly, this is a degenerative valvular disease that is preceded by aortic sclerosis. This valve undergoes fibrosis and calcification as it progresses over the years. The risk factors for the development of AS are hypertension, diabetes, tobacco smoking, and hyperlipidemia .
In the developing world, the most common cause of AS is rheumatic fever, regardless of age.
Aortic Regurgitation (AR)
The predominant etiologies of acute cases are infective endocarditis and aortic dissection. In contrast, adult chronic AR is a consequence of diseases such as degenerative aortic valve and root , rheumatic fever, infective endocarditis, myxomatous degeneration and trauma. Chronic AR in children is attributed to a ventricular septal defect that is accompanied by aortic valve prolapse.
Mitral Stenosis (MS)
Rheumatic fever accounts for most cases of MS.
Mitral Regurgitation (MR)
Mitral Valve Prolapse (MVP)
The most prevalent condition that leads to MVP is myxomatous degeneration, which is usually idiopathic but may be inherited in an autosomal dominant pattern.
Pulmonic Stenosis (PS)
This is typically congenital and found in children as part of the Tetralogy of Fallot constellation.
Pulmonic Regurgitation (PR)
Pulmonary hypertension is responsible for the majority of PR cases.
Tricuspid Regurgitation (TR)
Tricuspid Stenosis (TS)
Rheumatic fever is the preceding event in approximately all patients with TS.
Congenital AS is observed in 3 to 5 of 1000 live births. As for patient demographics, there is a male gender preference.
Another abnormality, MVP, is prevalent in 1% to 3% of normal populations. There is no gender preference.
Hemodynamic changes and heart structural changes often develop in valvular diseases.
AS leads to an elevated pressure load, resulting in compensatory LV hypertrophy (LVH). Note that LV dysfunction will not improve if the impaired contractility cannot be reversed .
In this disease, the mitral valve undergoes structural changes characterized by thickening and firming of the leaflets. Also, the commissures fuse and obstruct the orifice.
Stenosis may be accompanied by regurgitation. Additionally, compensatory mechanisms feature the enlargement of the LA and an increase in pressure. If the pressure in the pulmonary vasculature is elevated, one of the main consequences is pulmonary hypertension. The latter leads to further complications.
Note that dilatation of the LA can cause atrial fibrillation which in turn may lead to the formation of emboli.
Chronic cases result in volume overload and the compensatory LV hypertrophy (LVH) and LA hypertrophy (LAH). The compensatory stage can last for many years . Eventually, the disease progresses to a state of decompensation and LV dysfunction, reduced ejection fraction, and pulmonary involvement.
Prolapse is described as the ballooning of valvular leaflets into the LA during contraction. The pathology responsible for the changes in the leaflets is due to myxomatous degeneration, in which the valve becomes thinner and mucoid substances gather on the leaflets. Furthermore, rupture of the defected chorda may result in regurgitation.
This is associated with RV dilatation and the resultant heart failure.
Prophylactic treatment is indicated with certain valvular replacements. The clinician should consult the guidelines when managing patients with valve pathologies.
Aortic stenosis secondary to arteriosclerosis may be prevented with lifestyle modifications, such as the treatment of hypertension, achieving glycemic control, smoking cessation, and maintaining a healthy weight.
Infective endocarditis due to intravenous drug use can be prevented with safe life choices.
Heart valve disease comprises multiple cardiovascular conditions in which one or more of the valves are damaged or deformed. The valvular diseases have complex underlying pathologies and profound manifestations. Additionally, valve abnormalities may coexist with others as well, hence complicating the clinical sequelae.
Aortic stenosis (AS) is the obstruction of blood flow from the left ventricle (LV) to the aorta in the systolic phase while aortic regurgitation (AR) is characterized by backflow of blood into the LV during diastole. Both are associated with poor outcomes.
Mitral stenosis (MS) is the obstruction of the mitral valve opening that hinders the flow of blood from the left atrium (LA) to the LV. Another disease of this valve is the mitral regurgitation (MR), in which blood fluxes back to the LA.
Pulmonary outflow is affected in pulmonic stenosis (PS) in which case blood returns from the pulmonary artery back to the right ventricle (RV) in pulmonary regurgitation (PR).
In tricuspid stenosis (TS), the valve is narrowed and therefore, impeding blood flux to the RV whereas regurgitation (TR) is the insufficiency of blood flow to the right atrium (RA).
The clinical pictures of these conditions vary according to their severity. Moreover, clinical assessment includes the history of the patient and family, evaluation of current symptoms, a thorough physical exam, and imaging techniques such as echocardiography.
There are novel diagnostic modalities and advances in surgical approaches which include repair, replacement, or valvuloplasty. Additionally, better understanding of these diseases and their outcomes have helped guide the decision-making process.
What are valve diseases?
Abnormal and defective valves constitute a significant group of heart diseases. When the heart valves are affected, this results in many heart problems such as enlarged heart chambers and heart failure.
Valves are the channels that allow blood to flow from one chamber to another, from a blood vessel to a heart chamber, or from a heart chamber to a vessel.The heart is made up of 4 chambers. The top chambers are known as the right and left atria. The bottom chambers are known as the right and left ventricles.
How does blood flow through the heart?
Blood coming from the body enters the right atrium, which then pumps the blood through the tricuspid valve to the right ventricle. The blood then travels from the right ventricle through the pulmonic valve to the pulmonary artery. After the blood flows through the lungs to receives oxygenation, it travels back to the heart, specifically into the left atrium.The blood then flows through the mitral valve to the left ventricle. Finally, the blood travels through the aortic valve into the large blood vessel known as the aorta. The aorta distributes the oxygenated blood to the brain and the rest of the body.
What are the valvular diseases?
The valves are classified according to their defect. When a valve is associated with stenosis, it means there is a narrowing of the opening. Therefore, blood flow is obstructed.When a valve involves regurgitation, the blood returns back to the chamber or vessel it came from. The following are valvular diseases:
Each one of these is associated with causes, complications, its own set of outcomes/prognosis, and treatment. Also, a vast majority of valve diseases may not present with any symptoms until later in life.
How are these diseases diagnosed?
The diagnosis is achieved by evaluation of the patient’s symptoms (if present), personal and family history, an echocardiogram and other imaging techniques if needed. The echocardiogram is an ultrasound of the heart. This very important and useful test will provide information about the anatomy and function of the valves as well as the function and size of the heart.
How are they treated?
Treatment depends on the valve disease, the degree of severity, the presence of symptoms, the age of the patient, and other heart and medical problems present in the patient. Also, it is very important, if the patient is suitable for surgery or not. The surgical treatment will involve repair or replacement of the valve.
Patients before and after surgery need to be monitored so that prompt treatment may be provided.