Myocardial Infarction Flashcards
What is myocardial infarction(heart attack)?
An acute coronary syndrome which describes the short term and long term changes as blood flow decreases or stops to a part of the heart, causing damage to the heart muscle.
Refers to tissue death (infarction) of the heart muscle (myocardium).
Common symptoms of heart attack?
Chest pain (left or center, is most common) with nausea, sweating, vomiting, fainting or discomfort which may travel into the shoulder, arm, back, neck, upper abdomen or jaw. The discomfort may occasionally feel like heartburn. Other symptoms: shortness of breath, nausea, feeling faint, a cold sweat, palpitations, ab-normalcy in heart or feeling tired
What can MI cause?
Can cause heart failure, an irregular heartbeat, cardiogenic shock, tissue death or cardiac arrest
Most occur because of coronary artery disease.
Heart with a limited blood supply subject to increased oxygen demands, such as in fever, a fast heart rate, hyperthyroidism, less red blood cells in the bloodstream, or low blood pressure. Damage or failure of procedures such as percutaneous coronary intervention or coronary artery bypass grafts
What are some risk factors of MI?
High blood pressure, smoking, diabetes, lack of exercise, obesity, high blood cholesterol, poor diet, and excessive alcohol intake, male sex, low levels of physical activity, a past family history, tobacco smoking and obesity
High levels of blood cholesterol is a known risk factor, particularly high low-density lipoprotein, low high-density lipoprotein, and high triglycerides
What is the underlying mechanism of MI?
The complete blockage of a coronary artery caused by a rupture of an atherosclerotic plaque
What are tests used to diagnose MI?
ECGs, blood tests, and coronary angiography
An ECG, which is a recording of the heart’s electrical activity, may confirm an ST elevation MI (STEMI) if ST elevation is present. Commonly blood tests include troponin and less often creatine kinase MB
What is the immediate treatment for MI?
Aspirin is an appropriate immediate treatment for a suspected MI. Beta blockers and statin are recommended after MI.
Nitroglycerin or opioids may be used to help with chest pain but they do not improve overall outcomes.
Supplemental oxygen should be used in those with low oxygen levels or shortness of breath.
What are the treatments for STEMI which restores blood flow to the heart?
Percutaneous coronary intervention (PCI), where the arteries are pushed open and may be stented Thrombolysis, where the blockage is removed using medications
What are the treatments for people with NSTEMI?
Non-ST elevation myocardial infarction (NSTEMI) use blood thinner heparin, with the additional use of PCI in those at high risk.
What are treatments for people with blockages of multiple coronary arteries and diabetes?
Coronary artery bypass surgery (CABG) may be recommended rather than angioplasty.
When does MI occur and how is it measured and classified?
Occurs when there is cell death, as measured by a blood test of cardiac enzymes such as troponin or CK-MB. When there is evidence of an MI, it may be classified as an ST elevation myocardial infarction (STEMI) or Non-ST elevation myocardial infarction (NSTEMI) based on the results of an ECG.
How is MI different from heart attack?
An MI is different from—but can cause—cardiac arrest, where the heart is not contracting at all or so poorly that all vital organs cease to function, thus causing death. It is also distinct from heart failure, in which the pumping action of the heart is impaired. However, an MI may lead to heart failure.
What is Levine’s sign?
A person localizes the chest pain by clenching one or both fists over their sternum, thought to be predictive of cardiac chest pain.
Pain that responds to what does not indicate the presence or absence of MI?
Nitroglycerin
Which symptom of MI occurs when damage to the heart limits the output of the left ventricle, with breathlessness arising either from low oxygen in the blood, or pulmonary edema?
Shortness of breath.
