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Emergency and Acute Medicine: Valvular Heart Disease
Valvular heart disease refers to dysfunction of one or more heart valves, leading to either obstruction of forward blood flow (stenosis) or backward leakage (regurgitation). The four major conditions commonly encountered in emergency and clinical practice are mitral stenosis, mitral regurgitation, aortic stenosis, and aortic regurgitation. These disorders alter cardiac hemodynamics and may lead to heart failure, arrhythmias, or sudden death.
Mitral stenosis is characterized by obstruction of diastolic blood flow from the left atrium to the left ventricle, most commonly due to rheumatic fever. In contrast, mitral regurgitation results from failure of the mitral valve to close properly, allowing blood to flow backward into the left atrium. Acute mitral regurgitation causes sudden pressure overload leading to pulmonary edema, while chronic disease leads to left ventricular dilation and hypertrophy.
Aortic stenosis involves obstruction of left ventricular outflow, leading to increased systolic pressure and concentric hypertrophy of the left ventricle. It is commonly caused by calcific degeneration or congenital bicuspid valve. Aortic regurgitation, on the other hand, allows backflow of blood from the aorta into the left ventricle during diastole, resulting in volume overload. Acute aortic regurgitation can rapidly lead to pulmonary edema and heart failure, whereas chronic disease leads to progressive ventricular dilation.
Pregnancy significantly increases circulatory demands and may worsen underlying valvular disease, increasing the risk of thromboembolic events. In elderly patients, degenerative changes are the most common cause, particularly affecting the aortic and mitral valves. Surgical valve replacement is frequently required in advanced disease.
Clinically, symptoms vary depending on the valve involved. Mitral stenosis presents with exertional dyspnea, fatigue, orthopnea, and hemoptysis, along with a low-pitched diastolic murmur and opening snap. Mitral regurgitation is associated with dyspnea, atrial fibrillation, and a high-pitched pansystolic murmur radiating to the axilla. Aortic stenosis classically presents with the triad of angina, syncope, and heart failure, along with a harsh systolic murmur radiating to the carotids and delayed pulse upstroke. Aortic regurgitation presents with wide pulse pressure, bounding pulses, and a high-pitched diastolic murmur, along with characteristic peripheral signs such as head bobbing and nail-bed pulsations.
Evaluation includes a thorough history and cardiovascular examination, supported by ECG and chest X-ray findings such as chamber enlargement or pulmonary congestion. Laboratory tests may include blood cultures if Infective endocarditis is suspected. Imaging with echocardiography is essential for assessing valve structure, function, and severity of disease, while CT may be required in suspected aortic dissection.
Management depends on the specific lesion and whether it is acute or chronic. Initial stabilization follows standard resuscitation principles, including oxygen, monitoring, and IV access. Mitral stenosis is treated with diuretics and rate control (e.g., beta-blockers or digoxin), especially in atrial fibrillation. Acute mitral regurgitation requires urgent afterload reduction and may need surgical intervention. Aortic stenosis requires cautious management—vasodilators such as nitrates should be avoided, and gentle fluid management is essential. Aortic regurgitation is managed with afterload reduction and diuretics, with urgent surgery in acute cases.
Disposition depends on severity. Patients with hemodynamic instability, new arrhythmias, pulmonary edema, or acute valve dysfunction require admission. Stable patients with chronic disease may be discharged with close cardiology follow-up.
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