cardiomegaly

Cardiomegaly refers to an enlarged heart. It is not a disease itself but a radiologic or echocardiographic finding that reflects changes in heart muscle or structure. The most common signs are an enlarged cardiac silhouette on chest X-ray and increased heart size on echocardiography.

Causes include dilated cardiomyopathy, chronic hypertension with left ventricular hypertrophy, ischemic heart disease, valvular disease (such as aortic stenosis or mitral regurgitation), congenital heart disease, and exposure to cardiotoxic agents. Other contributors include thyroid disease, obesity, and physiologic enlargement in athletes. Acute conditions such as myocarditis or volume overload can also produce enlargement.

Pathophysiology varies; remodeling with chamber dilation or wall thickening leads to impaired systolic or diastolic function. Presentation ranges from none to symptoms of heart failure (dyspnea, edema, orthopnea), chest pain, palpitations, or arrhythmias. The degree of dysfunction largely determines prognosis and treatment focus.

Diagnosis involves history and examination, ECG, chest X-ray (cardiothoracic ratio >50% suggests enlargement), and echocardiography to measure chamber sizes and left ventricular ejection fraction. Additional tests may include cardiac MRI, stress testing, and labs (BNP, thyroid and renal function) to identify reversible contributors and the underlying cause.

Management targets the underlying cause and associated heart failure symptoms. Guideline-directed medical therapy for reduced ejection fraction, including ACE inhibitors or ARBs, beta-blockers, and mineralocorticoid receptor antagonists, is common. Diuretics relieve congestion. Blood pressure control, treatment of valvular disease, lifestyle modification, and, in select cases, device therapy (ICD or CRT) or surgery may be indicated. Prognosis depends on etiology and functional status.