Cardiology: Acute Coronary Syndrome Flashcards
how is ACS defined?
spectrum of clinical syndromes caused by plaque disruption or vasospasm that leads to acute myocardial ischemia
what is unstable angina defined as?
chest pain that is new onset, accelerating or occurs at rest, distinguished from stable angina pectoris by pt history
how is unstable angina different from NSTEMI?
unstable=signals impeding infarction base on plaque instability. no elevation in cardiac enzymes, but ST changes in ECG
NSTEMI=myocaridal necrosis marked by elevations in troponin I and CK-MB without St segment elevations on ECG
how are pts with ACS risk stratified?
using Thrombolysis in Myocardial Infarction (TMI) History: Age>65 years >3CAD risk factors Known CAD (stenosis >50%) ASA use in past 7 days Presentation: Severe angina (>2 episodes w/i 24 hrs) ST deviation >0.5mm \+cardiac marker each factor is 1 pnt >3pnts= higher risk pts
how is ACS treated?
same as for stable angina
clopidogrel, unfractionated heparin, enoxaparin
what should be given to ACS pts with chest pain refractory to medical therapy, an TIMI score >3 a troponin elevation, or ST changes>1mm
give IV heparin and schedule angiography and possible revascularization (percutaneous coronary intervention PCI or CABG)
how is STEMI defined?
ST elevation myocardial infarction is defined as ST-segment elevations and cardiac enzymes secondary to prolonged cardiac ischemia and necrosis
how does STEMI present?
acute onset substernal chest pain, commonly described as pressure or tightness that can radiate to left arm, neck or jaw
what associated symptoms of STEMI?
diaphoresis, SOB, lightheadedness, anxiety, nausea/vomiting, and syncope
what PE findings are associated with STEMI?
arrhythmias, hypotension (cardiogenic shock), and evidence of new CHF
what is the best predictor of survival in STEMI?
left ventricular EF
what MOAN mnemonic for treatment of MI
Morphine
Oxygen
NItrogen
ASA
how is STEMI seen on ECG?
ST segment elevations or new LBBB.
posterior wall infarct=ST segment depression and dominant R waves in leads V1-V2
Describe sequence changes in STEMI
peaked T waves, ST segment elevation, Q waves, T wave inversion, ST segment normalization, T wave normalization over several hrs to days
what is the most sensitive and specific cardiac enzyme? what other enzymes are checked? when do they rise?
troponin I
CK-MB and CK-MB/total CK ration (CK index)
both can take up to 6hrs to rise following onset of chest pain
ST segment elevation in which leads is associated with inferior MI? which arteries are involved? what should be obtained afterwards?
II, III, avF
involves the RCA/PDA and :CA
obtain an right-sided ECG to look for ST elevations in the right ventricle
ST segment elevations in which leads is associated with anterior MI? which arteries?
leads V1-V4
involves the LAD and diagonal branches
ST segment elevations in which leads points to a lateral MI? which artery?
I, avL, and V5-V6
LCA
ST segment depression in leads V1-V2 is associated with? what should be obtained?
acute transmural infarct in posterior wall
obtain posterior ECG leads V7-V9 to assess for ST segment elevations
describe typical pattern of serum marker elevation after an acute MI. include myoglobin, CK-MB, LD1, MLC, cTnl, and cTnT
see figure 2.1-9 on pg 33
A woman is found with pulseless electrical activity on hospital day 7 after suffering a lateral wall STEMI. The ACLS protocol is initiated. What is the next best step?
this pt has likely suffered a left ventricular free wall rupture with acute cardiac tamponade. emergent pericardiocentesis is the next best therapeutic and diagnostic step
what six key medications should be considered in treatment of ACS?
ASA, beta-blockers, clopidogrel, morphine, nitrates, and O2
If pt with ACS is in heart failure or cardiogenic shock, do not give what? what should be given instead?
beta-blockers
give ACEIs provided pt is no hypotensive
what procedures should be performed in pt with ACS?
emergent angiography and PCI
what is the time limit for PCI? what can be given after this?
90 minutes
after this there is no contranindication to thrombolysis,if within 3 hrs of chest pain onset given tPa and thrombolysis, reteplase, or streptokinase
what is longterm treatment for ACS?
ASA, ACEIs, beta blockers, high dose statins, and clopidogrel (if PCI was performed)
name indications for CABG using mnemonic UnLimiTeD
Unable to perform PCI (diffuse disease)
Left main coronary artery disease
Triple-vessel disease
Depressed ventricular function
what is the most common complication following acute MI? what is most frequent cause of death?
arrhythmia
letal arrhythmia
name some less common complications following acute MI?
reinfarction, left ventricular wall rupture, VSD, pericarditis, papillary muscle rupture (with MR), left ventricular aneurysm or pseudoaneurysm, and mural thrombi
define Dressler’s syndrome? when does it occur? how does it present? (5 symptoms)
autoimmune process, occurs 2-10 weeks post MI, presents with fever, pericarditis, pleural effusion, leukocytosis, and increased ESR
describe the timeline of common post-MI complications as follows
first day-1
heart failure
describe the timeline of common post-MI complications as follows
2-4 days (2)
arrhythmia, pericarditis
describe the timeline of common post-MI complications as follows
5-10 days (5)
left ventricular wall rupture (acute pericardial tamponade causing electrical alternans, pulseless electrical activity), papillary muscle rupture (severe mitral regurgitation)
describe the timeline of common post-MI complications as follows
wks-months (6)
ventricular aneurysm (CHF, arrhythmia, persistent St-segment elevation, mitral regurgitation, thrombus formation)
