Coronary artery disease (CAD),also called coronary heart disease (CHD),ischemic heart disease (IHD),myocardial ischemia,or simply heart disease,involves the reduction of blood flow to the cardiac muscle due to build-up of atherosclerotic plaque in the arteries of the heart. It is the most common of the cardiovascular diseases. Types include stable angina,unstable angina,and myocardial infarction.
Troponin,or the troponin complex,is a complex of three regulatory proteins that are integral to muscle contraction in skeletal muscle and cardiac muscle,but not smooth muscle. Measurements of cardiac-specific troponins I and T are extensively used as diagnostic and prognostic indicators in the management of myocardial infarction and acute coronary syndrome. Blood troponin levels may be used as a diagnostic marker for stroke or other myocardial injury that is ongoing,although the sensitivity of this measurement is low.
Coronary thrombosis is defined as the formation of a blood clot inside a blood vessel of the heart. This blood clot may then restrict blood flow within the heart,leading to heart tissue damage,or a myocardial infarction,also known as a heart attack.
Cardiac markers are biomarkers measured to evaluate heart function. They can be useful in the early prediction or diagnosis of disease. Although they are often discussed in the context of myocardial infarction,other conditions can lead to an elevation in cardiac marker level.
Stephen E. Epstein is the Head of Translational and Vascular Biology Research at the MedStar Heart and Vascular Institute,MedStar Washington Hospital Center and Clinical Professor of Medicine at the Georgetown University School of Medicine.
Acute coronary syndrome (ACS) is a syndrome due to decreased blood flow in the coronary arteries such that part of the heart muscle is unable to function properly or dies. The most common symptom is centrally located pressure-like chest pain,often radiating to the left shoulder or angle of the jaw,and associated with nausea and sweating. Many people with acute coronary syndromes present with symptoms other than chest pain,particularly women,older people,and people with diabetes mellitus.
A primary care physician (PCP) is a physician who provides both the first contact for a person with an undiagnosed health concern as well as continuing care of varied medical conditions,not limited by cause,organ system,or diagnosis. The term is primarily used in the United States. In the past,the equivalent term was 'general practitioner' in the US;however in the United Kingdom and other countries the term general practitioner is still used. With the advent of nurses as PCPs,the term PCP has also been expanded to denote primary care providers.
Unstable angina is a type of angina pectoris that is irregular or more easily provoked. It is classified as a type of acute coronary syndrome.
Percutaneous coronary intervention (PCI) is a minimally invasive non-surgical procedure used to treat narrowing of the coronary arteries of the heart found in coronary artery disease. The procedure is used to place and deploy coronary stents,a permanent wire-meshed tube,to open narrowed coronary arteries. PCI is considered 'non-surgical' as it uses a small hole in a peripheral artery (leg/arm) to gain access to the arterial system,an equivalent surgical procedure would involve the opening of the chest wall to gain access to the heart area. The term 'coronary angioplasty with stent' is synonymous with PCI. The procedure visualises the blood vessels via fluoroscopic imaging and contrast dyes. PCI is performed by an interventional cardiologists in a catheterization laboratory setting.
P2Y12 is a chemoreceptor for adenosine diphosphate (ADP) that belongs to the Gi class of a group of G protein-coupled (GPCR) purinergic receptors. This P2Y receptor family has several receptor subtypes with different pharmacological selectivity,which overlaps in some cases,for various adenosine and uridine nucleotides. The P2Y12 receptor is involved in platelet aggregation and is thus a biological target for the treatment of thromboembolisms and other clotting disorders. Two transcript variants encoding the same isoform have been identified for this gene.
Bivalirudin,sold under the brand names Angiomax and Angiox,among others,is a specific and reversible direct thrombin inhibitor (DTI). Chemically,it is a synthetic congener of the naturally occurring drug hirudin,found in the saliva of the medicinal leech Hirudo medicinalis. It is manufactured by The Medicines Company.
Door-to-balloon is a time measurement in emergency cardiac care (ECC),specifically in the treatment of ST segment elevation myocardial infarction. The interval starts with the patient's arrival in the emergency department,and ends when a catheter guidewire crosses the culprit lesion in the cardiac cath lab. Because of the adage that "time is muscle",meaning that delays in treating a myocardial infarction increase the likelihood and amount of cardiac muscle damage due to localised hypoxia,ACC/AHA guidelines recommend a door-to-balloon interval of no more than 90 minutes. As of 2006 in the United States,fewer than half of STEMI patients received reperfusion with primary percutaneous coronary intervention (PCI) within the guideline-recommended timeframe. It has become a core quality measure for the Joint Commission on Accreditation of Healthcare Organizations (TJC).
Troponin I is a cardiac and skeletal muscle protein family. It is a part of the troponin protein complex,where it binds to actin in thin myofilaments to hold the actin-tropomyosin complex in place. Troponin I prevents myosin from binding to actin in relaxed muscle. When calcium binds to the troponin C,it causes conformational changes which lead to dislocation of troponin I. Afterwards,tropomyosin leaves the binding site for myosin on actin leading to contraction of muscle. The letter I is given due to its inhibitory character. It is a useful marker in the laboratory diagnosis of heart attack. It occurs in different plasma concentration but the same circumstances as troponin T - either test can be performed for confirmation of cardiac muscle damage and laboratories usually offer one test or the other.
A myocardial infarction (MI),commonly known as a heart attack,occurs when blood flow decreases or stops in one of the coronary arteries of the heart,causing infarction to the heart muscle. The most common symptom is retrosternal chest pain or discomfort that classically radiates to the left shoulder,arm,or jaw. The pain may occasionally feel like heartburn.
Cocaine intoxication refers to the subjective,desired and adverse effects of cocaine on the mind and behavior of users. Both self-induced and involuntary cocaine intoxication have medical and legal implications.
Reperfusion therapy is a medical treatment to restore blood flow,either through or around,blocked arteries,typically after a heart attack. Reperfusion therapy includes drugs and surgery. The drugs are thrombolytics and fibrinolytics used in a process called thrombolysis. Surgeries performed may be minimally-invasive endovascular procedures such as a percutaneous coronary intervention (PCI),which involves coronary angioplasty. The angioplasty uses the insertion of a balloon and/or stents to open up the artery. Other surgeries performed are the more invasive bypass surgeries that graft arteries around blockages.
Francis Miller Fesmire was an American emergency physician and a nationally recognized expert in myocardial infarction. He authored numerous academic articles and assisted in the development of clinical guidelines on the standard of care in treating patients with suspected myocardial infarction by the American College of Emergency Physicians and the American Heart Association/American College of Cardiology. He performed numerous research investigations in chest pain patients,reporting the usefulness of continuous 12-lead ECG monitoring,two-hour delta cardiac marker testing,and nuclear cardiac stress testing in the emergency department. The culmination of his studies was The Erlanger Chest Pain Evaluation Protocol published in the Annals of Emergency Medicine in 2002. In 2011 he published a novel Nashville Skyline that received a 5 star review by ForeWord Reviews. His most recent research involved the risk stratification of chest pain patients in the emergency department.
Management of acute coronary syndrome is targeted against the effects of reduced blood flow to the affected area of the heart muscle,usually because of a blood clot in one of the coronary arteries,the vessels that supply oxygenated blood to the myocardium. This is achieved with urgent hospitalization and medical therapy,including drugs that relieve chest pain and reduce the size of the infarct,and drugs that inhibit clot formation;for a subset of patients invasive measures are also employed. Basic principles of management are the same for all types of acute coronary syndrome. However,some important aspects of treatment depend on the presence or absence of elevation of the ST segment on the electrocardiogram,which classifies cases upon presentation to either ST segment elevation myocardial infarction (STEMI) or non-ST elevation acute coronary syndrome (NST-ACS);the latter includes unstable angina and non-ST elevation myocardial infarction (NSTEMI). Treatment is generally more aggressive for STEMI patients,and reperfusion therapy is more often reserved for them. Long-term therapy is necessary for prevention of recurrent events and complications.
Harlan M. Krumholz,MD,SM is an American cardiologist,leading research scientist,and the Harold H. Hines,Jr. Professor of Medicine at Yale School of Medicine,where he has been on faculty since 1992. A pioneer in the development of the field of outcomes research,his groundbreaking contributions to science have directly led to improvements in healthcare outcomes for patients and populations. He is an international expert in the science to evaluate and improve the quality and efficiency of care,reduce disparities,improve integrity in medical research,promote better health policies and regulations,and promote patient-centeredness in research and clinical care. He is the founder and director of the Yale New Haven Hospital Center for Outcomes Research and Evaluation.
Mental stress-induced myocardial ischemia (MSIMI) is a medical condition in which acute psychological stress can trigger a transient myocardial ischemia,which is a state of reduced blood flow to the heart muscle,often without the presence of significant coronary artery disease (CAD). It is distinct from conventional stress ischemia caused by physical exertion or pharmacological agents. MSIMI is often silent and detected through specific cardiac function tests during mental stress challenges.
