The mitral valve acts as a one-way doorway in the heart, separating the upper left chamber (left atrium) from the lower left chamber (left ventricle). Mitral valve regurgitation occurs when this valve fails to close completely, allowing a portion of blood to flow backward into the left atrium with each heartbeat. This backward leak reduces the amount of blood pumped forward to the body and creates pressure changes within the heart.
Understanding Mitral Valve Regurgitation
Mitral valve regurgitation involves a leak in the valve regulating blood flow between the heart’s two left-sided chambers. When the left ventricle contracts to push oxygenated blood out to the body, the mitral valve leaflets should seal tightly. In regurgitation, the leaflets do not meet fully, allowing blood to flow backward into the left atrium during the contraction phase (systole).
This backward flow decreases the heart’s pumping efficiency, forcing the organ to work harder to maintain adequate circulation. Over time, the increased volume and pressure in the left atrium can transmit backward into the pulmonary veins, leading to pressure build-up in the lungs. The heart’s chambers may also enlarge, or dilate, as they attempt to compensate for the continuous strain.
The Spectrum of Symptoms
The most common sensation people experience is a profound feeling of tiredness or exhaustion, medically termed fatigue. This is a direct consequence of the heart struggling to pump enough oxygen-rich blood forward to meet the body’s metabolic demands. Even routine activities can feel draining, and the energy deficit often does not improve with rest.
Many individuals notice shortness of breath, which often worsens during physical exertion. When the backflow of blood causes pressure to rise in the lungs’ blood vessels, fluid can leak into the lung tissue, creating pulmonary congestion. This fluid accumulation can also make it difficult to breathe when lying flat, a symptom that may cause people to wake up suddenly struggling for air.
Some people report an awareness of their own heartbeat, described as heart palpitations, which may feel like a fluttering, racing, or pounding sensation in the chest. These irregular rhythms can be triggered by the stretching of the left atrium due to the extra volume of blood accumulating there. Swelling, or edema, particularly in the ankles and feet, occurs because the less efficient heart fails to move blood quickly enough, causing fluid to pool in the lower extremities.
Common Causes of Regurgitation
Mitral valve regurgitation is categorized based on whether the damage affects the valve itself (primary) or the surrounding heart structure (secondary).
Primary Regurgitation
Primary regurgitation involves a structural defect of the valve apparatus, such as the leaflets or the cords that anchor them. The most frequent cause is mitral valve prolapse, where one or both leaflets bulge back into the left atrium. Other structural issues include sudden tearing of the tissue cords, or degeneration of the valve due to age and wear. Infections like endocarditis, or damage from rheumatic fever, can also scar and distort the valve leaflets.
Secondary Regurgitation
Secondary regurgitation occurs when a problem elsewhere in the heart pulls the normal valve structures apart. Examples include weakening after a heart attack or an enlarged heart muscle (cardiomyopathy).
Recognizing When to Seek Medical Attention
While chronic mitral valve regurgitation can progress slowly, requiring regular monitoring, certain symptoms signal an urgent need for medical evaluation. A sudden or severe worsening of shortness of breath that interferes with speaking or simple movement should prompt immediate attention. This acute change may indicate a sudden mechanical failure of the valve, such as a ruptured cord, which the heart cannot compensate for.
Severe chest discomfort or pressure, especially when accompanied by sweating or lightheadedness, should never be ignored. Any instance of fainting or profound dizziness (syncope or presyncope) suggests that the heart is failing to pump enough blood to the brain. Furthermore, any development of a fever, chills, or general feeling of illness should be reported, as a damaged valve is more susceptible to dangerous infections like endocarditis.