outline of cardiology outline of cardiology the following outline is provided as an overview of and topical guide to cardiology, the branch of medicine dealing with disorders of the human heart. the field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology. physicians who specialize in cardiology are called cardiologists. what type of thing is cardiology cardiology can be described as all of the following: an academic discipline branch of science branch of applied science branch of medicine branch of internal medicine branches of cardiology adult cardiology – cardiac electrophysiology – study of the electrical properties and conduction diseases of the heart. clinical cardiac electrophysiology –clinical cardiac electrophysiology, is a branch of the medical specialty of cardiology and is concerned with the study and treatment of rhythm disorders of the heart. cardiologists with expertise in this area are usually referred to as electrophysiologists. electrophysiologists are trained in the mechanism, function, and performance of the electrical activities of the heart. cardiogeriatrics (geriatric cardiology) –cardiogeriatrics, or geriatric cardiology, is the branch of cardiology and geriatric medicine that deals with the cardiovascular disorders in elderly people. echocardiography – use of ultrasound to study the mechanical function/physics of the heart. interventional cardiology – use of catheters for the treatment of structural and ischemic diseases of the heart. nuclear cardiology – use of nuclear medicine to visualize the uptake of an isotope by the heart using radioactive sources. pediatric cardiology – pediatric cardiologists specialize in diagnosing and treating heart problems in children. anatomy of the heart heart – chordae tendinae – right atrium – right ventricle – tricuspid valve – left atrium – left ventricle – mitral valve – endocardium – myocardium – pericardial cavity – transverse pericardial sinus – pericardium – physical exam main article: cardiac examination the cardiac physical exam focuses on portions of the physical exam that elucidate information about diseases and disorders outlined below. clinical judgment, of course, should guide the physical exam but the following are pertinent things related to a general / broad cardiac exam. apex beat (point of maximum impulse) bruits: carotid, renal edema of the lower extremities and ascites that may indicate right heart failure heart sounds, heart murmurs, pericardial rub, mechanical heart valve clicking jugular venous distension retina exam with ophthalmoscope for signs of hypertension (retinal hemorrhage) and diabetic retinopathy (cotton wool spots) pulses: carotid, dorsalis pedis, femoral, popliteal, posterior tibial, radial, temporal, ulnar heart rate pulse quality: pulsus paradoxus, pulsus parvus et tardus respiratory sounds for crackles (edema) and other lung pathologies that can affect the heart rheumatic diseases can have significant cardiac findings and is too lengthy to include here arthritis is common amongst rheumatic diseases skin exam for rashes (systemic lupus erythematosus, scleroderma, dermatomyositis, vasculitis) skin exam diabetic neuropathy endocarditis signs: janeway lesions, osler's nodes, splinter hemorrhages peripheral vascular disease scars indicating procedures: sternotomy, thoracotomy, pericardial window, carotid endarterectomy, thyroidectomy, etc. skin bulges indicating implanted devices: pacemaker, icd, implantable loop recorder, vagus nerve stimulation vasculitis rashes xanthomas & xanthelasmas vital signs blood pressure – hypertension, congenital heart disease manifestations heart rate – bradycardia & tachycardia respiratory rate – in distress, shortness of breath causes heart disorders hypertension – elevated blood pressure above "normal." long term high blood pressure is a major risk factor for coronary artery disease, stroke, heart failure, peripheral vascular disease, vision loss, and chronic kidney disease. lowering blood pressure is key for preventing these diseases. types of hypertension essential hypertension – hypertension with no known cause, which is about 90–95% of people with hypertension. often thought to be due to lifestyle. management is through medications and blood pressure that does not respond is a red flag that it may be secondary hypertension. due to the widespread nature of hypertension, cardiologists will end up managing or recommending treatments for essential hypertension. secondary hypertension – most causes of secondary hypertension are from kidney and endocrine disorders. cardiovascular causes of hypertension include coarctation of aorta, atherosclerosis, and aortic stenosis. complications of hypertension hypertrophic cardiomyopathy – increased pressure results in hypertrophy of the myocardium, particularly left ventricular hypertrophy. pulmonary hypertension — which is separate from "hypertension" described above — can result in right ventricular hypertrophy. hypertensive crisis – generally considered to be a systolic blood pressure over 180. if there is no organ dysfunction it is called a hypertensive urgency, but if there is (e.g., confusion, breathlessness) then it is called hypertensive emergency. pre-eclampsia (pree) / eclampsia – pree is a disease of pregnancy that results in hypertension and proteinuria. pree has negative consequences for both the mother and fetus/baby. progression to eclampsia involves seizures. currently, the only definitive treatment is delivery of the fetus. hemorrhagic stroke – infarction of the brain due to internal bleeding from charcot–bouchard aneurysms. hypertensive encephalopathy, hypertensive nephropathy, hypertensive retinopathy – damage to organs from chronic hypertension. cardiac arrhythmias – conditions in which the heartbeat is irregular, too fast, or too slow. many types of arrhythmia have no symptoms. when symptoms are present these may include palpitations or feeling a pause between heartbeats. more seriously there may be lightheadedness, passing out, shortness of breath, or chest pain. while most types of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure. others may result in cardiac arrest. atrial fibrillation (afib or af) – fibrillation of the atria is fairly common and more common with increased age and overall disease of the heart. if the ventricular rate exceeds 100 then the afib is further classified as "afib with rvr" meaning rapid ventricular response. atrial flutter (afl) – a re-entrant tachycardia greater than 240 beats per minute and produces a characteristic saw-tooth pattern on ecg. it often degenerates to atrial fibrillation. heart block – a decrease in the ability of the conduction system to transmit action pulses in the orderly manner. blockage of the signal at different areas results in different types of heart block (e.g., first-degree av block, left bundle branch block). long qt syndrome – lengthening of the qt interval can result in arrhythmias and sudden cardiac death. specifically, it can lead to torsades de pointes than can then lead to ventricular fibrillation. it can be an inherited disorder or be acquired. certain medications are associated with lengthening of the qt interval — drug-induced qt prolongation — and an ekg may be warranted before starting the medication to ensure a normal qt interval, but this practice is debated. premature atrial contractions (pacs or apcs) – normal beats originate in the sa node and extra beats originating from the atria are called pacs. they can be found in normal hearts and be asymptomatic; symptomatic pacs can be treated with beta blockers. pacs, like pvcs, can pair up with normal beats in a pattern called bigeminy. premature ventricular contractions (pvcs) – normal beats are conducted through the av node to the ventricles resulting in a narrow qrs complex. with pvcs, the extra beat originates within the ventricles and results in a wide qrs complex. like pacs, they can be found in healthy hearts but are more likely to be found in bigeminy than pacs. sick sinus syndrome, bradycardia-tachycardia syndrome (bts) – disease of the sa node that results in irregular changes in heart rate and in the case of bts the arrhythmia alternates between bradycardia and tachycardia. supraventricular tachycardia (svt) – a collection of tachycardia rhythms that originate before the ventricles and include the sa node, atria, and av node. it is a broad, encompassing term that includes other rhythms in this list (e.g., afib with rvr) and others. torsades de pointes – a polymorphic arrhythmia that can be symptomatic and tends to resolve to a normal sinus rhythm. however, there is a concern ventricular fibrillation (vfib) – fibrillation of the ventricles is a life-threatening arrhythmia and should be treated by defibrillation and is a medical emergency. vfib results from uncoordinated contraction of the ventricles and defibrillation acts as a 'reset' to synchronize contraction (i.e., a normal rhythm). ventricular tachycardia (vtach) – tachycardia that originates from within the ventricles. typically, "vtach" implies monomorphology but it can be an umbrella term for both monomorphic and polymorphic (i.e., torsade de pointes). to classify a ventricular rhythm as vtach, at least 3 beats in a row must originate from the ventricles and have a rate over 100. if it lasts longer than 30 seconds, it can additionally be labelled as a sustained vtach. coronary circulation disorders atherosclerosis – atherosclerosis is the condition in which an artery wall thickens as the result of a build-up of fatty materials (e.g., cholesterol) and white blood cells ("foam cells"). atherosclerosis of a coronary artery leads to coronary artery disease (cad). atherosclerosis is a broad term referring to loss of elasticity of arteries and more specific terms exist — arteriosclerosis and arteriolosclerosis — to narrow which arteries are diseased and can easily be confused due to similar spelling. overall, atherosclerosis tends to affect the arteries of highest pressure: aorta, coronary, renal, femoral, cerebral, and carotid. coronary artery disease (cad)– coronary artery disease is a general term for any reduction in coronary circulation. one such cause is atherosclerosis. cad can lead to ischemia (angina pectoris) or infarction (myocardial infarction). treatment of cad includes angioplasty, stenting, and coronary artery bypass surgery (cabg). acute coronary syndrome (acs) – acs is a medical emergency and is a broad term encompassing many acute myocardial infarction symptoms. as a syndrome, it consists of a constellation of symptoms and can have many causes. the top three causes of acs are st elevation myocardial infarction (stemi, 30%), non st elevation myocardial infarction (nstemi, 25%), or unstable angina (38%). the first two are myocardial infarctions which are more commonly known as "heart attacks." angina pectoris – angina pectoris literally means "chest pain" that refers to pain caused by ischemia of the heart. the main cause of angina is coronary artery disease, but can result from other non-atherosclerotic causes such as anemia and heart failure. stable angina results if the angina resolves with rest or nitroglycerin, but can progress to unstable angina which is a form of acute coronary syndrome. myocardial infarction (also known as heart attack) – a myocardial infarction is the death of a part of the heart which is typically caused by a blockage of the coronary circulation but can be caused by other insufficiency such as cardiogenic shock. restenosis – recurrence of stenosis after being treated (e.g., stenting). cardiac arrest – cessation of normal systemic circulation due to failure in proper contraction of the heart. there are several conditions that can cause cardiac arrest. treatment of cardiac arrest includes cardiopulmonary resuscitation (cpr), defibrillation, and advanced cardiac life support (acls), and treatment of the underlying cause of arrest. asystole ("flatline") – asystole refers to the absence of electrical activity of the heart and is sometimes referred to as a "flatline" because the electrocardiogram shows a solid line due to the absence of electrical activity. this flatline is commonly used in television and movies to signal death. there are numerous causes of asystole that may be reversible if determined quickly enough, however, survival is very unlikely (~2% if not in a hospital). in contrast, asystole is desired and induced during cardiopulmonary bypass through a cardioplegia solution containing very high amounts of potassium. one additional example is the use of high potassium in lethal injection that results in asystole, cardiac arrest, and then death. pulseless electrical activity (pea) – pulseless electrical activity is when the electrocardiogram shows a rhythm that should produce a pulse but it does not. pea is commonly caused by the 6 h's and 6 t's (see pea article) and results in decreased cardiac output and insufficient oxygen delivery to the body. pulseless ventricular tachycardia – pulseless ventricular tachycardia (vt) is one classification of vt such that no pulse is felt because of an ineffective cardiac output which causes cardiac arrest, which also results in insufficient oxygen delivery to the body. sudden cardiac death (scd) – concept of natural death rather than a specific medical condition. there are several causes of sudden cardiac death and it is distinct from cardiac arrest. the leading cause of scd in young athletes is hypertrophic cardiomyopathy but can also result from commotio cordis that is often sustained during athletic activity. ventricular