The cardiovascular system Myocardial Infarction - definition, symptoms, treatment and ECGMyocardial Infarction - definition, symptoms, treatment and ECG
What is Myocardial Infarction and Definition
Death of HEART tissue. The most common cause of myocardial infarction is occlusion of the CORONARY ARTERIES such as occurs as a consequence of CORONARY ARTERY DISEASE (CAD) or less frequently of coronary ARTERY spasm. Myocardial infarction is the clinical term doctors use for HEART ATTACK. The MYOCARDIUM has very high oxygen needs, as oxygen is the only energy source for myocardial cells (unlike most other cells in the body, except the BRAIN, that also use GLUCOSE for energy). Myocardial tissue does not have significant ability to regenerate.
Myocardial tissue that dies not only can no longer contract to aid in the heart’s function but also cannot conduct electrical impulses to reach undamaged tissue. Myocardial infarction results in “dead” areas of the heart MUSCLE that cannot participate in the CARDIAC CYCLE, which often results in ARRHYTHMIA as well as ineffective pumping ability. The cellular structure of these areas changes, initially becoming soft and subsequently becoming fibrous (scarlike). New arteries are often able to develop, through a process called angiogenesis, to carry BLOOD around infarcted areas of the heart. This helps the rest of the heart remain functional. However, large infarctions may overcome the heart, resulting in heart attack or CARDIAC ARREST.
Diagnosis Myocardial Infarction and Treatment
ELECTROCARDIOGRAM (ECG) and ECHOCARDIOGRAM are the diagnostic procedures that typically identify myocardial infarction. Treatment includes eliminating the cause of the infarction, such as coronary artery occlusion, and stabilizing the heart’s function to the best extent possible with medications. Because CAD is nearly always the culprit, ANGIOPLASTY or CORONARY ARTERY BYPASS GRAFT (CABG) are nearly always among the treatment options.
See also CARDIOVASCULAR DISEASE PREVENTION; MEDICATIONS TO TREAT CARDIOVASCULAR DISEASE; MICROINFARCTION; MYOCARDIAL PERFUSION IMAGING; STROKE; SURGERY BENEFIT AND RISK ASSESSMENT; TRANSIENT ISCHEMIC ATTACK (TIA).
