Care of Patients with Acute Coronary Syndromes Flashcards
coronary artery disease
single largest killer of American men and women ion all ethnic groups, Broad term that includes chronic stable angina and acute coronary syndromes. Affects the arteries that provide blood, oxygen, and nutrients to the myocardium. Ischemia occurs when insufficient oxygen is supplied to meet the requirements. Infarction occurs when severe ischemia is prolonged and decreased perfusion causes irreversible damage to tissue.
angina pectoris
chest pain caused by temporary imbalance between the coronary arteries’ ability to supply oxygen and the cardiac muscle’s demand for oxygen. ischemia that occurs is limited in duration and does not cause permanent damage.
Two types: chronic stable angina and unstable angina
chronic stable angina
chest discomfort that occurs with moderate to prolonged exertion in a pattern that is familiar to the patient. Frequency, duration, and intensity of symptoms remain the same over several months. Results in only slight limitation of activity and is usually associated with a fixed atherosclerotic plaque. Usually relieved by nitroglycerin or rest; managed with drug therapy.
acute coronary syndrome
term used to describe patients who have either unstable angina or acute myocardial infarction. Atherosclerotic plaque in the coronary artery ruptures, resulting in platelet aggregation (clumping), thrombus (clot) formation and vasoconstriction. ACS classified into one of three categories according to the presence or absence of ST- segment elevation on the ECG and positive serum troponin markers:
- STEMI: ST elevated MI (traditional manifestation)
- NSTEMI: Non ST elevated MI (common in women)
- unstable angina pectoris
unstable angina pectoris
chest pain or discomfort that occurs at rest or with exertion and causes severe activity limitation. Pressure may last longer than 15 min. Poorly relieved by rest or nitroglycerin. May present with ST changes but do not have changes in troponin or creatine kinase levels.
New onset angina
variant Prinzmetal’s angina
Pre-infarction angina
new onset angina
describes the patient who has his or her first angina symptoms, usually after exertion or other increased demands on the heart.
variant Prinzmetal’s angina
chest pain or discomfort resulting form coronary artery spasm and typically occurs after rest.
pre-infarction angina
refers to chest pain that occurs in the days or weeks before an MI
Myocardial Infarction (MI or AMI)
occurs when myocardial tissue is abruptly and severely deprived of oxygen. When blood flow is quickly reduced by 80% to 90%, ischemia develops. Ischemia can lead to injury and necrosis of myocardial tissue if blood flow is not restored. Evolves over a period of several hours. Extent of infarction depends on collateral circulation, anaerobic metabolism and workload demands. Physical changes do not occur in the heart until 6 hours after the infarction. Once infarction occurs, scare tissue permanently changes the size and shape of the entire left ventricle, called ventricular remodeling.
NSTEMI
Non ST segment elevation myocardial infarction. ST and T-wave changes on ECG. Indicates myocardial ischemia. Cardiac enzymes may be initially normal but elevate over the next 3-12 hours.
causes of a NSTEMI
coronary vasospasm, spontaneous dissection, sluggish blood flow due to narrowing of the coronary artery.
STEMI
ST elevated myocardial infarction. ST elevation in two leads on a ECG. Indicates myocardial infarction/necrosis. Attributable to rupture of the fibrous atherosclerotic plaque leading to platelet aggregation and thrombus formation at the site of rupture. Thrombus causes an abrupt 100% occlusion to the coronary artery.
CAD/ ACS Etiology
atherosclerosis is the primary factor in the development of CAD; non-modifiable and modifiable risk factors contribute to atherosclerosis
non-modifiable risk factors of atherosclerosis
age, gender, family history, ethnic background
modifiable risk factors of atherosclerosis
elevated serum lipid levels, smoking, limited physical activity, HTN, DM, obesity, excessive alcohol, excessive stress/ decrease coping skills.
CAD/ACS incidence
average age for first MI, 65.1 years in men, 72 for women, postmenopausal women have lower incidence than men, postmenopausal women in their 70s or older have an equal chance.
CAD/ACS health promotion
control or alter modifiable risk factors for CAD
CAD Prevention
eliminate smoking and tobacco use, diet, have lipid levels checked regularly, increase physical activity, manage diabetes, manage HTN, manage weight, limit alcohol use, manage stress
Physical assessment of ACS
may complain of pain or pressure, assess according to onset, location, radiation, intensity, duration, precipitating factors, relieving factors.
assess for associated symptoms such as NV, diaphoresis, dizziness, weakness, palpitations, SOB
assess BP, HR, Cardiac rhythm, dysrhythmias; sinus tach with PVC frequently occur in the first few hours after an MI
assess distal peripheral pulses and skin temp; poor cardiac output can be manifested by cool, diaphoretic skin and diminished or absent pulses.
auscultate for S3 gallop which often indicates HF (complication of MI)
assess resp rate and breath sounds, crackles and wheezes may indicate LSHF
assess for presence of JVD and peripheral edema.
Assess for fever, patient with MI may experience temperature elevation for several days, in response to myocardial necrosis, indicating the inflammatory response.
key features of angina
substernal chest discomfort: radiating to the left arm, precipitated by exertion or stress (or rest in variant angina) relieved by nitroglycerin or rest, lasting less than 15 min.