Heart Valves: Detailed Explanation - Comprehending Anatomy, Classification, Role, Related Diseases, and Other Key Points
The heart's four valves - the mitral, aortic, tricuspid, and pulmonic valves - each play a crucial role in maintaining the flow of blood through the heart. Unfortunately, these valves can be affected by similar common conditions, primarily stenosis (narrowing) and regurgitation (leakage), which impair proper blood flow.
### Common Conditions by Valve
The mitral valve, which closes off the left atrium, allowing oxygenated blood from the lungs to flow through to the left ventricle, is most often affected. Common issues include mitral regurgitation, where the valve does not close properly, causing backward flow into the left atrium, and mitral stenosis, where narrowing limits blood flow from the left atrium to the left ventricle. Causes include degenerative disease, rheumatic heart disease, congenital defects, and endocarditis (infection).
The aortic valve, the final valve that oxygen-rich blood passes through before exiting the heart and coursing through the rest of the body, can suffer from aortic stenosis, where the valve thickens or hardens, narrowing the path through which blood can flow, and aortic regurgitation, where the valve leaks, causing blood to flow back into the left ventricle. Degenerative calcification and congenital abnormalities are common causes.
The tricuspid valve, with three flaps called cusps or leaflets, can experience tricuspid regurgitation, often secondary to right heart dilation or pulmonary hypertension, and tricuspid stenosis, which is less common and may result from rheumatic disease or congenital problems.
The pulmonic valve, which closes off the right ventricle and opens to allow the blood to flow to the lungs, can suffer from pulmonary stenosis, where congenital valve narrowing impairs blood flow, and pulmonary regurgitation, where leakage often secondary to valve dilation or prior surgeries occurs.
### Treatments
Treatment depends on the valve affected, disease type and severity, and patient condition.
Mild or early valve disease can be managed by monitoring via regular follow-ups and imaging. Medications can control heart rhythm, rate, and fluid retention. Treating underlying conditions like hypertension or arrhythmias can slow valve damage progression.
Minimally invasive procedures, such as balloon valvuloplasty, are used mainly for stenotic valves (e.g., mitral or pulmonic stenosis), where a catheter-mounted balloon is inflated to open the narrowed valve.
Surgical repair is preferred if feasible, especially for mitral valve regurgitation or mild-to-moderate disease. Minimally invasive mitral valve repair involves smaller incisions, reducing pain, bleeding, and recovery time compared to open surgery.
When repair is impossible or valve damage is severe, valve replacement is done either surgically or via transcatheter approaches like TAVR (transcatheter aortic valve replacement). Types of replacement valves include mechanical valves, durable but requiring lifelong anticoagulation, and biological (tissue) valves, made from animal tissue, less thrombogenic but may deteriorate over time, potentially inducing immune response or calcification.
In patients with severe aortic stenosis unsuitable for surgery, TAVR has shown reduced mortality and hospitalization despite some risks (e.g., stroke, vascular complications) with sustained valve function up to 5 years post-procedure.
In summary, the four heart valves are susceptible mainly to stenosis and regurgitation. Treatments range from medical management and minimally invasive procedures to surgical repair or replacement, often tailored to the specific valve involved, disease severity, and patient factors. Minimally invasive techniques improve recovery and reduce complications compared to open surgery.
- Beyond just the four main valves, other heart diseases like mitral stenosis and regurgitation, aortic stenosis and regurgitation, tricuspid regurgitation, and pulmonic stenosis can be linked with medical conditions affecting cardiovascular health, posing a threat to health-and-wellness.
- Science plays a crucial role in the advancement of treatments for these valve conditions, as medical research continually explores new approaches for management, from medications to minimally invasive procedures, surgery, and various types of valve replacement, each tailored to the specific valve, disease severity, and patient's unique health situation.
