fibrillation – ventricular fibrillation is fibrillation of the ventricles of the heart. rhythmic contraction is necessary for efficient movement of blood, and fibrillation disrupts this rhythm sufficiently to cause cardiac arrest. disorders of the myocardium cardiomyopathy – cardiomyopathy is a deterioration of the myocardium. several classifications have been used to categorize cardiomyopathies with the most common being primary vs. secondary, and dilated vs. restrictive vs. hypertrophic (presented below). ischemic cardiomyopathy – cardiomyopathy causing ischemia of the heart due to coronary artery disease. nonischemic cardiomyopathy – cardiomyopathy caused by something other than ischemia. amyloid cardiomyopathy – cardiomyopathy caused by amyloidosis. hypertrophic cardiomyopathy (hcm) – cardiomyopathy caused by hypertrophy of the heart and is the leading cause of sudden cardiac death in young adults. hypertrophic obstructive cardiomyopathy (hocm) (idiopathic hypertrophic subaortic stenosis (ihss)) : dilated cardiomyopathy (dcm) – cardiomyopathy caused by dilation of the heart, typically caused by "drugs and bugs." it is the most common form of non-ischemic cardiomyopathy and the dilatation of the heart results in larger chamber volumes & thinner myocardial walls, both of which decrease the ability to pump. specific kinds of dilated cardiomyopathy are listed below, and other causes include chagas disease, chemotherapeutic agents (e.g., doxorubicin), tuberculosis, and pregnancy. alcoholic cardiomyopathy – a type of dilated cardiomyopathy caused by chronic abuse of alcohol and results from direct toxicity of ethanol on the myocardium. tachycardia induced cardiomyopathy – a type of dilated cardiomyopathy caused by chronic tachycardia. a common arrhythmia that can lead to this form of cardiomyopathy is the common atrial fibrillation. takotsubo cardiomyopathy (transient apical ballooning, stress-induced cardiomyopathy) – a type of dilated cardiomyopathy caused by a sudden temporary weakening of the myocardium, which can include emotional stress (i.e. broken-heart syndrome). it presents as sudden heart failure with ecg changes similarly found in myocardial infarction and typically is found in post-menopausal women. arrhythmogenic right ventricular dysplasia (arrhythmogenic right ventricular cardiomyopathy) – cardiomyopathy caused by a genetic mutation of the desmosomes that connect myocytes. restrictive cardiomyopathy (rcm) – cardiomyopathy caused by excessive rigidity of the heart that prevents effective contraction and pumping. in comparison to dcm, rcm is often secondarily caused by other diseases such as amyloidosis, scleroderma, hemachromatosis (iron overload) and eosinophilic granulomatosis with polyangiitis. as such, the treatment for rcm is to treat the disease causing the rcm. heart failure – heart failure is failure of the heart to produce sufficient blood flow to meet metabolic demands of the body, or to do so at higher filling pressures. the hallmark signs of heart failure include shortness of breath (especially on exertion, at night, or while lying down) and leg swelling. chest pain is rarely a feature of heart failure, which would point a diagnosis more toward angina pectoris or myocardial infarction. perhaps confusingly, heart failure can be caused by coronary artery disease (cad) and myocardial infarction (mi) that result in a deficiency in pumping that then leads to heart failure. treatment of heart failure, like most secondary disorders, depends upon treatment of the primary cause which includes cad & mi but also valvular problems like aortic stenosis and hypertension. cor pulmonale – untreated cor pulmonale can cause right heart failure from chronic pulmonary hypertrophy. ventricular hypertrophy – hypertrophy of the ventricle. thickening of the myocardium (i.e., hypertrophy) can be physiological (a normal response) or pathological. an example of physiological hypertrophy is the result of significant athletic training (athletic heart syndrome). left ventricular hypertrophy (lvh) – hypertrophy of the left ventricle is more common than in the right and typically due to increased afterload on the heart such as from hypertension and aortic stenosis, but also from long standing mitral valve regurgitation. it can be diagnosed by echocardiography or ecg. right ventricular hypertrophy (rvh) – hypertrophy of the right ventricle and, it too, can be physiological from athletic training. other causes include pulmonary hypertension and copd as well as several congenital heart defects like ventricular septal defect, tetralogy of fallot and hypoplastic left heart syndrome. heart cancer – cancer of the heart is very rare and those cancers tend to be benign. myxoma – most common tumor of the heart. it is a benign tumor most commonly found in the left atrium and can be associated with carney syndrome. myocardial rupture and ventricular aneurysm – rupture is a gross structural failure of the heart. commonly a result of myocardial infarction that weakens the wall sufficiently to result in frank rupture and is typically seen 7–10 days after infarction. if not significant enough, the wall can develop into a ventricular aneurysm. myocarditis – infection and inflammation of the myocardium is myocarditis. most causes are infectious (parvovirus b19, lyme disease, chagas disease), toxic (ethanol, anthracyclines, clozapine), or immunologic (systemic lupus erythematosus, sarcoidosis, and some of the vasculitides (see below)). definitive diagnosis requires a biopsy. uhl anomaly – a congenital heart defect in which the right ventricular myocardium is too thin or absent. it is a very rare disorder. disorders of the pericardium pericarditis – inflammation of the pericardium that is typically idiopathic or infectious in nature. treatment of viral & idiopathic pericarditis is nsaids or aspirin. constrictive pericarditis – pericarditis that constricts the expansion of the heart and inhibits heart function. causes include infections (tuberculosis, fungus, parasites) and surgery. definitive surgery is a pericardiectomy. dressler syndrome – a form of pericarditis that develops 2–3 weeks after myocardial infarction and is accompanied by fever, pleuritic chest pain, and symptoms of pericarditis. pericardial effusion – the serous pericardium normally contains fluid that reduces friction, but an abnormal accumulation of fluid in the pericardium is called a pericardial effusion. the list of causes is lengthy but includes pericarditis, rheumatic diseases (e.g., systemic lupus erythematosus), trauma, and blood from myocardial rupture. if an effusion worsens then the fluid can inhibit heart function and symptoms of cardiac tamponade appear. treatment includes pericardiocentesis to drain the fluid, if necessary, and treatment of the underlying cause. pericardial tamponade – tamponade is a medical emergency resulting from accumulation of fluid in the pericardium that inhibits heart function. tamponade is a consequence of the fibrous pericardium being too inelastic to permit adequate heart expansion during diastole. the classic finding is pulsus paradoxus as well as beck's triad (low arterial blood pressure, distended neck veins, & soft heart sounds). treatment is supportive until in a hospital where pericardiocentesis or a pericardial window can be performed to drain the fluid. disorders of the heart valves specific valvular problems – specific problems of each valve. aortic valve – disorders and treatments of the aortic valve that separates the left ventricle and aorta. aortic regurgitation / aortic insufficiency – deficiency of the aortic valve that permits regurgitation from the aorta into the left ventricle. aortic stenosis – narrowing of the aortic valve opening that reduces blood flow through the valve. stenosis commonly occurs from calcification of the valve, which happens prematurely in those with a bicuspid aortic valve. stenosis of the aortic valve produces a harsh systolic murmur that classically radiates in the carotid arteries as well as pulsus parvus et tardus. aortic valve replacement – replacement of the aortic valve due to aortic regurgitation, aortic stenosis, or other reasons. a special kind of replacement called percutaneous aortic valve replacement is done through catheters are does not require open-heart surgery. aortic valve repair – repair, instead of replacement, of the aortic valve. aortic valvuloplasty – repair of the valve by using a balloon catheter to force it open. mitral valve – disorders and treatments of the mitral valve that separates the left atrium and left ventricle. mitral valve prolapse – prolapse of the mitral valve into the left atrium during ventricular systole. mitral regurgitation / mitral insufficiency – deficiency of the mitral valve that permits regurgitation from the left ventricle into the left atrium. regurgitation produces a systolic murmur that radiates into the axilla. mitral stenosis – narrowing of the mitral valve opening that reduces blood flow through the valve. mitral valve replacement – replacement of the mitral valve due to mitral regurgitation, mitral stenosis, or other reasons. mitral valve repair – repair, instead of replacement, of the mitral valve. mitral valvuloplasty – repair of the valve by using a balloon catheter to force it open. pulmonary valve – disorders of the pulmonary valve that separates the right ventricle and pulmonary artery. pulmonary regurgitation / pulmonary insufficiency – deficiency of the pulmonary valve that permits regurgitation from the pulmonary artery into the right ventricle. pulmonic stenosis – narrowing of the pulmonary valve opening that reduces blood flow through the valve. tricuspid valve – disorders of the tricuspid valve that separates the right atrium and right ventricle. tricuspid regurgitation / tricuspid insufficiency – deficiency of the tricuspid valve that permits regurgitation from the right ventricle into the right atrium. tricuspid stenosis – narrowing of the tricuspid valve opening that reduces blood flow through the valve. ebstein's anomaly – a congenital heart defect that results in the tricuspid valve leaflets being deeper in the heart (toward the apex) than normal. the annulus of the valve is in the correct position, however, and the portion of the ventricle affected becomes "atrialized" with thinner walls. the right atrium becomes hypertrophied and can result in conduction defects (e.g., wolff–parkinson–white syndrome). tricuspid atresia – a congenital heart defect that results in the absence of the tricuspid valve endocarditis – the thin, inner lining of the heart is the endocardium and inflammation of this layer is called endocarditis. endocarditis commonly affects the heart valves. infective endocarditis – commonly affects the valves due to absence of blood supply to the heart valve, which results in a decreased immune response to the valve leaflets. typically, bacteria cause infective endocarditis of the mitral valve, but intravenous drug users (e.g., heroin, methamphetamine) have an increased risk of infection of the tricuspid valve. common signs include janeway lesions (non-tender), osler's nodes (tender), and splinter hemorrhage of the nails. nonbacterial thrombotic endocarditis (nbte) – growths on the valves that are not from an infectious source and are composed of fibrin and platelets, and is associated with a history of rheumatic fever. the aortic valve is the most common valve affected (followed by mitral, tricuspid, & then pulmonary). libman–sacks endocarditis – a form of nonbacterial endocarditis specific to systemic lupus erythematosus (sle) and tends to affect the mitral valve (unlike nbte which affects the aortic valve). it is the second most common heart finding in sle after pericarditis congenital heart defects – defects in the structure of the heart which are present at birth and are often the result of aberrant embryological development. defects can be syndromic or non-syndromic, with the later meaning defects that are isolated and not found in patterns (i.e., a syndrome). the top two syndromic causes of congenital heart defects are noonan syndrome and down syndrome. down syndrome is more common than noonan syndrome, but has a lower incidence of congenital heart defects, which makes noonan syndrome the most common syndromic cause of congenital heart defects. atrial septal defect (asd) – defect in the interatrial septum that permits blood flow between atria, including a patent foramen ovale (pfo). bicuspid aortic valve – formation of two valve leaflets in the aortic valve instead of three leaflets. this leads to aortic stenosis as the valve prematurely calcifies (as compared to calcification of a trileaflet valve). coarctation of the aorta (coa) – narrowing of the aorta, typically of the aortic arch and is classically found in turner syndrome. a "complete" coarction is called an interrupted aortic arch. cor triatriatum – a membrane that divides one of the atria results in "three" atria (hence "triatriatum"). this tends to affect the left atrium more than the right atrium. the membrane may be present without complete division of the atrium. it presents similarly to stenosis of the respective semilunar valve (i.e., tricuspid stenosis for right atrium). dextrocardia – dextrocardia is a condition in which the apex of the heart is on the right side of the body, instead of the left. this can exist in isolation or as a part of situs inversus in which the entire body is mirrored not just the heart. situs inversus can be a part of primary ciliary dyskinesia (aka kartagener syndrome) that has recurrent respiratory infections and male infertility. a simple chest xray is sufficient to diagnose dextrocardia, provided