and HF Questions and Answers|Latest Update
Unstable Angina Enzymes Cardiac enzymes may take up to 12 hours to see levels
elevated in NSTEMI
*In UA cardiac enzymes may not be elevated
Acute Coronary Syndrome and Stable Angina Severity - much worse with ACS and will last
much longer
Partial relief with nitrates with stable angina - not ACS
Pain descriptors in angina - severe chest pain
Accompanying symptoms of ACS - diaphoresis, syncope, N/V, dizziness and impending doom
Acute Myocardial Infarction Ruptured plaque with thrombus formation
,Infarction - blood flow disruption is PROLONGED or blood flow disruption is TOTAL
ECG changes occur - ST elevation
Cardiac enzymes - troponin levels elevated
*Tissue will die and become necrotic
Infarction - irreversible injury occurs within: 30 min - 4 hours
Infarction - tissue necrosis begins by: 4 hours
*Limit the area of necrosis and recover the area of ischemia
Infarction - necrotic tissue is cleared away by: 1-2 weeks
,Infarction - tough fibrous scar tissue replaces necrotic tissue by: 6 weeks
*Will see permanent changes in EKG due to scar tissue
Myocardial Ischemia Causes Thrombus in coronary artery
Accumulation of hardened atherosclerotic plaque - which calcifies and becomes more fragile
Artery vasospasm - variant angina is caused by coronary artery spasm - when the artery relaxes
circulation is returned to the myocardial tissue
Anemia -the respiratory and circulatory systems are working properly but there are not enough
RBC to carry the O2
*Will start having symptoms as they exercise with increased plaque
If the coronary artery diameter is blocked by 50-70% an inadequate amount of blood flows past
the blockage and ischemia results: True
, *Less than 50% will have no symptoms typically
A patient with CAD will need a Hgb of at least: 8-9 g/dL
*Never less than 7 g/dL
Acute MI Is an acute coronary syndrome (ACS) that occurs when the heart tissue endures
prolonged ischemia without recovery
Myocardial cells suffer IRREVERSIBLE DAMAGE
MIs are classified according to findings on an ECG as: STEMI or NSTEMI
Three Factors - Reflecting Amount of Acute MI Damage 1. Location or level of occlusion in
the coronary artery
2. Length of time that the coronary artery has been occluded