Rheumatic aortic stenosis is a heart valve disorder impacting the aortic valve, which regulates blood flow from the heart’s main pumping chamber to the rest of the body. This condition involves a progressive narrowing of this valve, impeding the efficient ejection of oxygenated blood. Over time, this restriction can place an increased burden on the heart, affecting its ability to circulate blood effectively.
Understanding Rheumatic Aortic Stenosis
The aortic valve, normally composed of three thin leaflets, functions as a one-way gate, opening to allow blood to exit the left ventricle and closing to prevent backflow into the heart. In rheumatic aortic stenosis, these leaflets undergo structural changes, becoming thickened, stiff, and often fusing together along their edges. This fusion reduces the size of the valve opening, creating an obstruction to blood flow.
As the valve opening narrows, the left ventricle must exert greater pressure to push blood through the constricted passage. This increased workload causes the heart muscle to thicken and enlarge, a compensatory mechanism known as ventricular hypertrophy. Despite this adaptation, the heart’s efficiency diminishes over time, potentially leading to a reduced supply of oxygenated blood to the body’s tissues.
The Link to Rheumatic Fever
Rheumatic aortic stenosis originates from rheumatic fever, an inflammatory disease that can develop as a complication of an untreated or inadequately treated infection with Group A Streptococcus bacteria, commonly known as strep throat. If a strep infection is not fully resolved, the body’s immune response can sometimes mistakenly attack its own tissues, including those in the heart, joints, brain, and skin. This autoimmune reaction can lead to acute rheumatic fever.
During episodes of rheumatic fever, the heart valves can become inflamed, a condition termed carditis. While the initial inflammation may subside, the damage to the valve tissue can persist and progress silently over many years, sometimes decades. This chronic, progressive scarring and calcification of the heart valves, particularly the aortic valve, results in rheumatic heart disease, with aortic stenosis being a common manifestation.
Identifying the Symptoms
Individuals with rheumatic aortic stenosis may not experience noticeable symptoms for many years, as the heart initially compensates for the narrowing valve. However, as the stenosis progresses and the obstruction to blood flow becomes more pronounced, various signs can emerge. Shortness of breath, particularly during physical exertion or when lying flat, is a common complaint due to increased pressure in the lungs. Chest pain or angina can occur because the heart muscle, working harder, may not receive enough oxygen-rich blood.
Dizziness or lightheadedness, and even fainting episodes, may result from insufficient blood flow to the brain, especially during activity when the demand for blood increases. Fatigue and weakness are frequently reported as the body’s tissues receive less oxygen and nutrients. A distinct heart murmur, a whooshing sound heard with a stethoscope, is present due to turbulent blood flow through the narrowed valve.
Diagnostic Procedures and Treatment Options
Diagnosing rheumatic aortic stenosis begins with a thorough physical examination, where a physician listens for characteristic heart murmurs using a stethoscope. An echocardiogram, an ultrasound of the heart, is the definitive diagnostic tool; it provides detailed images of the valve’s structure, assesses the degree of narrowing, and measures blood flow velocity and pressure gradients across the valve. An electrocardiogram (ECG) can detect signs of an enlarged heart or abnormal heart rhythms, while a chest X-ray may show an enlarged heart silhouette or calcification of the aortic valve. Cardiac catheterization might be performed to directly measure pressures within the heart chambers and assess the severity of the stenosis.
Treatment approaches for rheumatic aortic stenosis depend on the severity of the valve narrowing and the presence of symptoms. Medical management involves medications to alleviate symptoms, such as diuretics to reduce fluid retention or drugs to control blood pressure or heart rate. For moderate to severe stenosis, surgical intervention is considered. Valve replacement surgery, where the damaged aortic valve is removed and replaced with a prosthetic valve (either mechanical or biological), is a common and effective treatment. Mechanical valves are durable but require lifelong anticoagulant medication, while biological valves may not last as long but do not require long-term anticoagulation.
Managing the Condition Long-Term
Long-term management of rheumatic aortic stenosis, especially after diagnosis or intervention, involves consistent medical follow-up to monitor heart function and overall health. Regular appointments with a cardiologist are important to assess the stability of the condition or the performance of a replaced valve. Adherence to prescribed medications, such as those for blood pressure control or anticoagulants for mechanical valves, is part of ongoing care.
Lifestyle adjustments are recommended, including maintaining a heart-healthy diet low in sodium and saturated fats, and engaging in appropriate levels of physical activity as advised by a healthcare provider. Preventing future infections, particularly bacterial endocarditis, is a priority; this involves prophylactic antibiotics before certain dental or surgical procedures. With proper medical oversight and patient adherence, individuals with rheumatic aortic stenosis can maintain a good quality of life.