Myocardial Infarction Flashcards
When does acute coronary syndrome occur
when the heart tissue endures prolonged ischemia without recovery
How is acute coronary syndrome classified
STEMI or nonSTEMI
STEMI heart attack
elevated ST, damage goes through the entire cardiac wall
nonSTEMI heart attack
depressed ST, damage does not go through the entire cardiac wall (subendocardial)
When does myocardial infarction begin
with coronary artery atherosclerosis with causes obstruction then ischemia
What are the ways an obstruction can occur
ruptured plaque attracts platelets, which then forms a thrombus
What can result if coronary artery blood supply remains constant but myocardial demands increase
severe hypertension, left ventricular hypertrophy
Risk factors
atherosclerosis, hyperlipidemia, diabetes, hypertension, smoking, family history
What is the extent of damage influenced by
location/level of occlusion in coronary artery, length of time the coronary artery is occluded, and heart’s availability of collateral circulation
Womens s/s
SOB, sweating, nausea, vomiting, ingestion, panic/anxiety
Diagnostic tests
ECG, blood tests, echocardiogram, coronary angiography
Blood tests
CPK-MB fraction, troponin 1
Why are blood tests used
when heart cells die, intracellular contents spill into the bloodstream
Troponin 1
a cardiac protein highly specific for cardiac muscle necrosis released only when myocardial cell death has occured
When does troponin increase
cell death
Echocardiogram
identifies what portion of the heart has been affected by the MI, identify abnormal wall motion/contractile dysfunction
Primary goal of treatment
re-establish blood flow to the heart muscle and minimize damage
What can be taken at the start of chest pain
antiplatelet agent (aspirin)
What does morphine do
pain relief, anxiety relief, improve gas exchange
Treatment options
antiplatelet agent, nitrates, morphine, thrombolytic medicine, beta-blockers, heparin, PTCA/CABG
Drug eluting stent
a polymer coating over the mesh, that emits a drug over time to help keep the blockage from coming back, stay slippery to prevent cells from getting stuck
Complications
dysrhythmias, papillary muscle rupture, thromboembolism, ventricular rupture, pericarditis, heart failure, cardiogenic shock
What happens if the cardiac muscle loses blood supply and electrical pathways are disrupted
the precise electrical pathways become interrupted because infarcted tissues no longer conduct
What complications can arise from disruption in electrical pathways
fatal dysrhythmias, ventricular tachycardia, ventricular fibrillation
What does slowing/blocking of impulses cause
some impulses to change direction, disrupt conduction, and the cardiac tissue to fire inappropriately
Follow-up
cardiac stress testing, cardiac rehabilitation, nutrition consultation, routine cardiologist visits
