Category Archives: Myocardial Infarction

ST-segment elevation myocardial infarction (STEMI) is the term cardiologists use to describe a classic heart attack. It is one type of myocardial infarction in which a part of the heart muscle (myocardium) has died due to the obstruction of blood supply to the area. The ST segment refers to the flat section of an electrocardiogram (ECG) reading and represents the interval between jagged heartbeats. When a person has a heart attack, this segment will no longer be flat but will appear abnormally elevated. STEMI is one of three types of acute coronary syndrome (ACS). ACS occurs when a plaque ruptures from within a coronary artery, causing the partial or complete obstruction of that artery. The obstruction itself is caused when blood clots form around the area of the rupture. When obstructed, the portion of the heart muscle serviced by that artery will quickly suffer from a lack of oxygen, called ischemia. Chest pains (angina) are often the first signs of this. If the obstruction is extensive enough, some of the heart muscle will begin to die, resulting in myocardial infarction. We categorize ACS by the level of obstruction and the resulting damage to the heart muscle: Regardless of how an … Continue reading →

It is often importantto be able to determine the localization of myocardial infarction and ischemia, as well as being able to determine which coronary artery that is iccluded, and where the occlusion may be located. As discussed below, this may facilitate diagnosis of ischemia and infarction, and it may also guide management. For example, administering nitroglycerin(to alleviate ischemic chest pain) may cause hemodynamic collapsein patients with right ventricular ischemia/infarction; therefore, it is crucial to recognize ECG signs of right ventricular ischemia/infarction. Most clinicians will benefit from this knowledge. For cardiologists particularly interventional cardiologists this knowledge is of paramount importance as they must be able to directly pinpoint where the coronary artery occlusion is located (itaffects the selection of coronary catheter). The termculprit which means the guilty one is used to denote the occluded coronary artery. In the vast majority of cases, it is only possible to determine the ischemic/infarct area (and thus the culprit) if the ECG displaysST segment elevations. However, there are a fewdistinct ECG syndromes (e.g Wellens syndrome, de Winters sign, global ST segment depressions) in which it is possible to determine the ischemic/infarct area despite theabsence of ST segment elevations. The two main coronary arteries emanate from … Continue reading →

An acute myocardial infarction, also called a heart attack, happens when a blood vessel in the heart suddenly becomes blocked. Blood vessels carry blood and oxygen. When a blood vessel in the heart gets blocked, blood cannot get to part of the heart. This part of the heart does not get enough oxygen. This is called ischemia. When the heart muscle becomes ischemic (does not get enough blood and oxygen), the ischemia often causes chest pain. This is called Angina Pectoris. If the ischemia lasts long enough, the heart muscle that is not getting enough oxygen dies. This is called an infarction. "Myocardial infarction" means "infarction (muscle death) in the heart muscle." A heart attack is a medical emergency. The first few minutes are very important for keeping the person alive. Some of the damage from the heart attack can be repaired if the person gets treatment during the first hour of the attack. Most heart attacks are caused by Coronary Artery Disease (CAD). In coronary artery disease, a wax-like material called plaque builds up on the inside walls of arteries in the heart. This is called atherosclerosis. Plaque is made of cholesterol and other cells. The amount of plaque … Continue reading →

[Guideline] Amsterdam EA, Wenger NK, Brindis RG, Casey DE Jr, Ganiats TG, Holmes DR Jr, et al. 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014 Dec 23. 130 (25):e344-426. [Medline]. [Full Text]. [Guideline] O'Gara PT, Kushner FG, Ascheim DD, et al. American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2013 Jan 29. 127 (4):e362-425. [Medline]. [Full Text]. [Guideline] Roffi M, Patrono C, Collet JP, et al. 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: Task Force for the Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-Segment Elevation of the European Society of Cardiology (ESC). Eur Heart J. 2016 Jan 14. 37 (3):267-315. [Medline]. [Full Text]. [Guideline] Task Force on the management of ST-segment elevation acute myocardial infarction of the European Society of Cardiology (ESC); Steg PG, James SK, Atar D, et al. ESC Guidelines for … Continue reading →

Myocardial infarction diagnosisMedical diagnosticsPurposediagnose myocardial infarct via physical exam and EKG(plus blood test) A diagnosis of myocardial infarction is created by integrating the history of the presenting illness and physical examination with electrocardiogram findings and cardiac markers (blood tests for heart muscle cell damage).[1][2] A coronary angiogram allows visualization of narrowings or obstructions on the heart vessels, and therapeutic measures can follow immediately. At autopsy, a pathologist can diagnose a myocardial infarction based on anatomopathological findings. A chest radiograph and routine blood tests may indicate complications or precipitating causes and are often performed upon arrival to an emergency department. New regional wall motion abnormalities on an echocardiogram are also suggestive of a myocardial infarction. Echo may be performed in equivocal cases by the on-call cardiologist.[3] In stable patients whose symptoms have resolved by the time of evaluation, Technetium (99mTc) sestamibi (i.e. a "MIBI scan"), thallium-201 chloride or Rubidium-82 Chloride can be used in nuclear medicine to visualize areas of reduced blood flow in conjunction with physiologic or pharmocologic stress.[3][4] Thallium may also be used to determine viability of tissue, distinguishing whether non-functional myocardium is actually dead or merely in a state of hibernation or of being stunned.[5] According to the … Continue reading →

[Guideline] Amsterdam EA, Wenger NK, Brindis RG, Casey DE Jr, Ganiats TG, Holmes DR Jr, et al. 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014 Dec 23. 130 (25):e344-426. [Medline]. [Full Text]. [Guideline] O'Gara PT, Kushner FG, Ascheim DD, et al. American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2013 Jan 29. 127 (4):e362-425. [Medline]. [Full Text]. [Guideline] Roffi M, Patrono C, Collet JP, et al. 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: Task Force for the Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-Segment Elevation of the European Society of Cardiology (ESC). Eur Heart J. 2016 Jan 14. 37 (3):267-315. [Medline]. [Full Text]. [Guideline] Task Force on the management of ST-segment elevation acute myocardial infarction of the European Society of Cardiology (ESC); Steg PG, James SK, Atar D, et al. ESC Guidelines for … Continue reading →

Ischemia occurs when part of the heart muscle, the myocardium, is deprived of oxygen and nutrients.Common causes of ischemia are: A short period of ischemia causes reversible effects: The heart cells will be able to recover. When the episode of ischemia lasts for a longer period of time, heart muscle cells die. This is called a heart attack or myocardial infarction. That is why it is critical to recognize ischemia on the ECG in an early stage. Severe ischemia results in ECG changes within minutes. While the ischemia lasts, several ECG changes will occur and disappear again. Therefore, it may be difficult to estimate the duration of the ischemia on the ECG, which is crucial for adequate treatment. Signs and symptoms of myocardial ischemia: Narrowing of the coronary artery, leading to a myocardial infarction, usually develops over several years. An increased risk of cardiovascular disease, which may lead to a myocardial infarction or cerebrovascular accident, can be estimated using SCORE system which is developed by the European Society of cardiology (ESC).As shown in the figure, the most important risk factors for myocardial infarction are: An exercise test such as a bicycle or treadmill test, may be useful in detecting myocardial … Continue reading →

Sources Used in Current Review Zafari, A.M. et. al. (2015 September 15, Updated). Myocardial Infarction. Medscape Drugs and Diseases [On-line information]. Available online at http://emedicine.medscape.com/article/155919-overview. Accessed on 11/01/15. (2015 August 14). About Heart Attacks. American Heart Association [On-line information]. Available online at http://www.heart.org/HEARTORG/Conditions/HeartAttack/AboutHeartAttacks/About-Heart-Attacks_UCM_002038_Article.jsp. Accessed on 11/01/15. (2014 December 17). Heart Disease and Stroke Statistics At-a-Glance. American Health Association [On-line information]. Available online at http://www.heart.org/idc/groups/ahamah-public/@wcm/@sop/@smd/documents/downloadable/ucm_470704.pdf. Accessed on 11/01/15. (2013 December 17, Updated). What Is a Heart Attack? National Heart Lung and Blood Institute [On-line information]. Available online at http://www.nhlbi.nih.gov/health/health-topics/topics/heartattack. Accessed on 11/01/15. Mayo Clinic Staff (2014 November 15). Heart Attack. Mayo Clinic [On-line information]. Available online at http://www.mayoclinic.org/diseases-conditions/heart-attack/basics/risk-factors/con-20019520. Accessed on 11/01/15. Warnica, J. (2013 May, Revised). Acute Coronary Syndromes (ACS). Merck Manual Professional Version [On-line information]. Available online at http://www.merckmanuals.com/professional/cardiovascular-disorders/coronary-artery-disease/acute-coronary-syndromes-acs. Accessed on 11/01/15. Lehman, C. and Straseski, J. (2015 September, Updated). Ischemic Heart Disease ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/IHD.html?client_ID=LTD. Accessed on 11/01/15. Sources Used in Previous ReviewsThomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition]. Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO. National Heart, Lung, and Blood … Continue reading →

A myocardial infarction or MI occurs when the blood supply to some part of the heart muscle is abruptly stopped. MIs are caused by a number of factors. In most cases a thrombus associated with plaque rupture occludes arteries, also less frequently embolization of arteries leads to MI or coronary spasm in the absence of plaque in arteries.[1] The assessment of a heart attack is commonly based on a person's history and on a physical exam. Since there are many causes of chest pain the first task of a naturopathic doctor or any other primary care physician is to rule out life threatening conditions.[2] In order to stimulate the innate ability of the body to heal the causes of disease must be identified and addressed. With Myocardial infarction, the causes are variable and include lifestyle, social and environmental factors. A detailed assessment is required to determine which risk factors are contributing to the overall risk an individual has of suffering a heart attack. Common questions regarding a heart attack include:[3] They would also inquire about your dietary and lifestyle habits, your exercise regimen and any acute or chronic stressors. The tests used to determine if you had a heart attack … Continue reading →

ST-segment elevation myocardial infarction (STEMI) is the term cardiologists use to describe a classic heart attack. It is one type of myocardial infarction in which a part of the heart muscle (myocardium) has died due to the obstruction of blood supply to the area. The ST segment refers to the flat section of an electrocardiogram (ECG) reading and represents the interval between jagged heartbeats. When a person has a heart attack, this segment will no longer be flat but will appear abnormally elevated. STEMI is one of three types of acute coronary syndrome (ACS). ACS occurs when a plaque ruptures from within a coronary artery, causing the partial or complete obstruction of that artery. The obstruction itself is caused when blood clots form around the area of the rupture. When obstructed, the portion of the heart muscle serviced by that artery will quickly suffer from a lack of oxygen, called ischemia. Chest pains (angina) are often the first signs of this. If the obstruction is extensive enough, some of the heart muscle will begin to die, resulting in myocardial infarction. We categorize ACS by the level of obstruction and the resulting damage to the heart muscle: Regardless of how an … Continue reading →