Mitral Valve Stenosis: Understanding Causes, Symptoms, and Impact on Heart Function

The human heart consists of four chambers — the left atrium, left ventricle, right atrium, and right ventricle. The mitral valve, also known as the bicuspid or atrioventricular valve, is located between the left atrium and the left ventricle. This complex structure is made up of seven components: part of the left atrial wall, the mitral annulus, leaflets, chordae tendineae, papillary muscles, part of the left ventricular wall, and the aortic valve support ring. Under normal conditions, the valve orifice measures between 4 to 6 cm², allowing unrestricted blood flow from the left atrium to the left ventricle regardless of cardiac output.

What Happens in Mitral Valve Stenosis?

Mitral stenosis occurs when the valve opening becomes narrowed, typically to less than 2 cm². This reduction in size disrupts normal hemodynamics, increasing pressure in the left atrium and affecting overall cardiac efficiency. As a result, blood encounters resistance when flowing from the atrium to the ventricle, leading to turbulent flow and a cascade of physiological changes.

Recognizing the Symptoms

Patients with mitral valve stenosis may experience a variety of symptoms, including shortness of breath, especially during physical activity or when lying flat. Many individuals report waking up at night gasping for air and needing to sit upright to breathe comfortably. Additional signs include chest tightness, persistent coughing, wheezing, production of sputum, and even hemoptysis (coughing up blood). These symptoms often worsen over time and can significantly impact quality of life if left untreated.

Why Early Detection Matters

Understanding the anatomy and function of the mitral valve is crucial in identifying stenosis early. Because the condition can progress slowly, many people may not realize they have a problem until symptoms become more severe. Regular cardiovascular checkups, especially for those with a history of rheumatic fever or other heart conditions, can help catch mitral stenosis before it leads to serious complications like heart failure or atrial fibrillation.