16.14: Rheumatic Heart Disease II: Clinical Manifestations and Diagnostic Studies

The key clinical manifestations of Rheumatic heart disease (RHD) include several distinct cardiac symptoms.

Carditis, a hallmark of acute rheumatic fever, involves inflammation of the heart's endocardium, myocardium, and pericardium. Chronic RHD often results from recurrent episodes of carditis. Its symptoms include the following:

• Murmurs are caused by valvular damage, especially to the mitral and aortic valves. Mitral stenosis or regurgitation is common, with characteristic heart murmurs detectable during auscultation.
• Heart failure, resulting from severe valvular damage, leads to symptoms such as fatigue, dyspnea, edema, and orthopnea.
• Although less common, pericarditis can present with chest pain, a pericardial friction rub, and signs of pericardial effusion.

RHD primarily affects the mitral valve, leading to valvular lesions with the following clinical manifestations.

• Mitral stenosis is the narrowing of the mitral valve, which can result in increased left atrial pressure, pulmonary hypertension, and atrial fibrillation.
• Mitral regurgitation is characterized by the incompetence of the mitral valve, resulting in blood flowing backward into the left atrium during systole.
• The aortic valve may be affected less frequently, leading to aortic stenosis or regurgitation.

Additionally, arrhythmias, particularly atrial fibrillation, are common due to left atrial enlargement secondary to mitral stenosis or regurgitation, potentially leading to palpitations, thromboembolism, and stroke.

Diagnostic Studies

Diagnosis of Rheumatic Heart Disease (RHD) relies on clinical manifestations, laboratory tests, and imaging studies to determine the extent of valvular damage and other cardiac complications resulting from rheumatic fever. The initial diagnosis often involves a thorough medical history and physical examination, with clinicians looking for a history of rheumatic fever and manifestations of heart murmur indicative of valvular damage.

Echocardiography is the primary imaging tool used in diagnosing RHD. Transthoracic echocardiography (TTE) provides detailed images of the heart's structure and function, allowing the detection of valvular lesions such as mitral stenosis or regurgitation, and assessment of left atrial size, ventricular function, and any vegetations or thrombi. When more detailed images are required, especially in assessing the mitral and aortic valves, transesophageal echocardiography (TEE) is used.

Electrocardiography (ECG) detects arrhythmias such as atrial fibrillation, common in patients with mitral stenosis or regurgitation. It can also show other abnormalities, like a prolonged PR interval, which indicates delayed atrioventricular (AV) conduction.

A chest X-ray can reveal cardiomegaly (enlargement of the heart), pulmonary congestion, and other signs of heart failure associated with severe valvular disease.

Doppler ultrasound is often performed alongside echocardiography to assess the severity of valvular stenosis or regurgitation by measuring the blood flow across the valves.

Additionally, blood tests such as antistreptolysin O (ASO) titer, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) support the diagnosis of rheumatic fever as the underlying cause of RHD. Elevated ASO titers indicate a recent streptococcal infection, while increased levels of CRP and ESR indicate an inflammatory response, helping to confirm the diagnosis and guide further treatment.