Ischemic Heart Disease (Exam IV) Flashcards
What chemical mediators are released from ischemia that activate cardiac nociceptors?
Adenosine and Bradykinin
What is the path for cardiac pain signals to reach the spinal cord?
Cardiac nociceptors → Afferent Neurons → T1 - T5 SNS ganglia.
What is the CNS response to cardiac ischemia?
- ↓ AV conduction and thus ↓HR
- ↓ Contractility
Differentiate stable vs unstable angina.
- Stable - No change in chest pain severity or frequency in 2-mo period.
- Unstable - Increasing frequency and severity of chest pain.
Are cardiac biomarkers (troponin) present with unstable angina?
NO. If they were, that would be an MI.
What EKG abnormality is associated with old MI’s and/or current ischemia?
T-wave inversion
What is nuclear stress testing utilized for?
Coronary Perfusion assessment
What determines the significance of CAD during a nuclear stress test?
Size of the perfusion abnormality
Arrows point to arrows of lesser perfusion.
What test can differentiate a new vs and old perfusion abnormality?
Nuclear Stress Testing
What nuclear stress test tracers are used with exercise?
Thallium
What nuclear stress test drugs are used without exercise?
Atropine
Dobutamine
Pacing
When are adenosine and dipyridamole used with nuclear stress testing? Why?
Used after test to dilate normal, non-ischemic areas of the heart.
What test would be useful for imaging wall motion abnormalities or valvular function?
Echocardiography
What is Prinzmetal Angina?
Coronary Spasm
What is the mechanism of action for aspirin?
COX-1 Inhibition → TXA2 inhibition → Plt aggregation inhibition.
How can aspirin be reversed?
Trick question. It can’t be, platelets are damaged until they die and are replaced.
What is the mechanism of action of abciximab, eptifibatide, and tirofiban?
Platelet glycoprotein IIb/IIIa receptor antagonists
Inhibit platelet activation, adhesion, and aggregation.
What drugs (discussed in lecture) are P2Y12 inhibitors?
Clopidogrel and Prasugrel
What common drug class will antagonize P2Y12 inhibitors?
PPIs
How does Prasugrel compare to Clopidogrel?
More predictable pharmacokinetics but greater bleeding risk.
How do P2Y12 inhibitors work?
Inhibit ADP receptor P2Y12 and thus inhibit platelet aggregation.
What drug classes are synergistic with nitrates?
- β-blockers
- CCBs
When are nitrates contraindicated?
- Aortic Stenosis
- Hypertrophic Cardiomyopathy
What drug class is the only one proven to prolong life in CAD patients?
β-blockers
What properties do β-blockers have?
- Anti-ischemia
- Anti-HTN
- Anti-dysrhythmic
Which β blockers are cardioselective?
- Atenolol
- Metoprolol
- Acebutolol
- Bisoprolol
Which β blockers are non-selective?
- Propanolol
- Nadolol
What risk is associated with non-selective β blockers in asthma patients?
↑ risk of bronchospasm in reactive airway disease patients.
What drug class is uniquely effective is decreasing the severity/frequency of coronary vasospasm?
CCBs
Angiotensin II will increase what four things?
- Myocardial hypertrophy
- Interstitial myocardial fibrosis
- Coronary vasoconstriction
- Inflammatory responses
Is troponin or CK-MB more specific for myocardial injury?
Troponin
How soon with troponin start to increase after myocardial injury?
3 hours
What diagnostic studies might indicate a myocardial infarction?
- EKG: abnormality (ex. LBBB)
- US: Regional wall motion abnormalities
What are indications for PCI treatment of an MI?
- Contraindicated tPa therapy
- Severe HF and/or pulm edema
- S/S for 2-3 hours
- Mature clot
What risks are associated with PCI (percutaneous coronary intervention) ?
- Endothelial destruction
- Bleeding
- Thrombosis
What is Dual Antiplatelet Therapy (DAPT) ?
- ASA w/ P2Y12
How long would one want to wait for elective surgery post angioplasty with no stenting?
2 - 4 weeks
How long would one want to wait for elective surgery post angioplasty with bare-metal stent placement?
At least 30 days (12 weeks preferable)
How long would one want to wait for elective surgery post angioplasty with drug-eluting stent placement?
At least 6 months (12 months if post ACS)
How long would one want to wait for elective surgery post-CABG?
At least 6 weeks (12 weeks preferable)
Is glycopyrrolate or atropine preferred for treatment of bradycardia?
Glycopyrrolate
Are β blockers or ACE-inhibitors continued peri-operatively?
β-blockers
Are β blockers or ACE-inhibitors discontinued 24 hours prior to surgery?
ACE inhibitors
What components are worth 1 point on the Revised Cardiac Risk Index (RCRI) ?
What % risk of major cardiac events would be conferred by a RCRI score of 0 ?
0.4%
What % risk of major cardiac events would be conferred by a RCRI score of 1 ?
1.0%
What % risk of major cardiac events would be conferred by a RCRI score of 2 ?
2.4%
What % risk of major cardiac events would be conferred by a RCRI score of ≥3 ?
5.4%
What does 1 MET equal?
3.5mLO₂/kg/min
What drug is the preferred treatment for tachycardia?
Esmolol
What anticholinergic is the better option for treatment of bradycardia in CAD patients?
Glycopyrrolate > Atropine
What coronary artery would you expect to be effected from abnormalities noted on II, III, and aVF?
RCA
What coronary artery would you expect to be effected from abnormalities noted on I and aVL?
Circumflex artery
What coronary artery would you expect to be effected from abnormalities noted on V3 - V5?
LAD
