structural heart disease

Structural heart disease encompasses organic abnormalities of cardiac valves, chambers, myocardium, pericardium, or great vessels. Major categories: (1) Valvular disease—stenosis (obstruction to flow) or regurgitation (backward flow) affecting any valve (aortic, mitral, pulmonary, tricuspid); common causes include rheumatic heart disease, endocarditis, degenerative disease (calcification), myxomatous degeneration (MVP); (2) Cardiomyopathies—dilated (systolic dysfunction from ischemia, alcohol, myocarditis), restrictive (impaired diastolic filling from infiltration or fibrosis), hypertrophic (thick myocardium, dynamic LVOT obstruction); (3) Myocarditis—inflammation of myocardium from viral infection (enterovirus, adenovirus), autoimmune disease, or toxic exposure; (4) Pericarditis—inflammation of pericardium from viral infection, autoimmune disease, uremia, or malignancy; (5) Congenital heart disease—atrial septal defect (ASD), ventricular septal defect (VSD), patent ductus arteriosus (PDA), tetralogy of Fallot, transposition of great arteries, coarctation of aorta. Presentation varies by lesion: valvular stenosis causes outflow obstruction (dyspnea, syncope, angina); regurgitation causes volume overload (dyspnea, peripheral edema); cardiomyopathy causes systolic/diastolic dysfunction (heart failure, arrhythmias); pericarditis causes pericardial pain, friction rub, tamponade risk. Diagnosis: physical exam findings (murmurs, rubs), ECG (chamber enlargement, ischemic changes), echocardiography (visualizes structures, quantifies valve dysfunction, measures EF). Management is lesion-specific: valve replacement/repair for severe valvular disease, beta-blockers and diuretics for cardiomyopathy, NSAIDs/colchicine for pericarditis.