Exam 2 - Ischemic Heard Disease Flashcards
What are the 2 most important risk factors for development of atherosclerosis?
- Male gender
- Increasing age
Non-modifiable risk factors
What are the first 3 manifestations of IHD?
- Angina pectoris
- Acute MI
- Sudden death (dysrhythmias)
What are the modifiable risk factors for IHD?
- High cholesterol
- HTN
- Smoking
- DM
- Obesity
- Sedentary lifestyle
What chemical mediators are released during 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
This decreases myocardial oxygen demand (good)
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 (chest pain at rest)
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
Tropnin levels bump in ____ , remain elevated for ____
3-4 hours
2 weeks
What is nuclear stress testing utilized for?
How is this done?
- Assessment of coronary perfusion
- Injection of thallium or technetium during exercise; decreased tracer activity = decreased blood flow
What test can differentiate a new vs and old perfusion abnormality?
Nuclear Stress Testing
What nuclear stress test drugs are used without exercise?
Atropine
Dobutamine
Pacing
Dipyridamole
What test would be useful for imaging wall motion abnormalities or valvular function?
Echocardiography
What is Prinzmetal Angina?
How can it be diagnosed?
- Coronary Spasm
- Angiography
- EKG will show ST segment elevation during angina
What test determines the location of occlusive disease and assesses results of stenting?
Coronary angiography
What test can measure the stability of plaques?
There is no satisfactory test to measure this yet
Most AMI occurs from rupture of a plaque that produced ____ stenosis of the coronary artery.
< 50%
Treatments for coronary atherosclerosis?
- Stop smoking
- Lose weight
- Diet changes
- Statins
- Treating HTN
What is the mechanism of action for aspirin?
COX-1 Inhibition → TXA2 inhibition → Plt aggregation inhibition.
How can aspirin be reversed?
Platelet transfusion
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?
MOA?
- Clopidogrel, Prasugrel, and Ticagrelor
- Prodrugs that inhibit ADP and platelet aggregation (irreversable)
What common drug class will antagonize P2Y12 inhibitors?
PPIs
This P2Y12 inhibitor has more stable pharmacokinetics but has a higher risk of bleeding?
Prasugrel (Effient)
CV effects of nitrates?
- Decreases angina pectoris
- ↓ SVR, preload
- Dilates coronaries
- Decreaes myocardial oxygen consumption
What drug classes are synergistic with nitrates?
- β-blockers
- CCBs
More pronounced hypotension
When are nitrates contraindicated?
- Aortic Stenosis
- Hypertrophic Cardiomyopathy
Reduces preload and CO which is vital for these patients
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 in the heart muscle?
- Myocardial hypertrophy
- Interstitial myocardial fibrosis
- Coronary vasoconstriction
- Inflammatory responses
ACE inhibitors treat?
- HTN
- HF
- Cardioprotective
These drugs reduce mortality in noncardiac and vascular surgeries?
Statins
When is revascularization necessary for IHD?
- Failure of medical therapy
- > 50 % L main coronary occlusion
- > 70 % occlusion of epicardial coronary
- EF < 40%
When is a CABG preferred over PCI?
- Significant left main coronary disease
- 3 vessel CAD
- DM with 2-3 vessel CAD
Which substances contribute to thrombogenesis?
- Collagen, ADP, epinephrine, serotonin
- Thromboxane A2
- Glycoprotein IIb/IIIa receptors
- Fibrin deposit
What criteria diagnoses a STEMI?
Detection of troponin AND at least one of the following:
- Symptoms of ischemia
- ECG changes (ST/T, new LBBB)
- Pathologic Q waves
- Regional wall motion abonormality
- Thrombus identified bia angiography
Is troponin or CK-MB more specific for myocardial injury?
Troponin
When is evaluation of with an echo helpful in patients with angina?
- LBBB
- Uncertain AMI diagnosis
- Suspected AAA
What is the primary goal in patients with a STEMI?
Reestablish blood flow ASAP
What 2 drugs should be avoided in patients with an acute STEMI?
- Glucocorticoids
- NSAIDs (besides aspirin)
When should thrombolytic therapy be given for MI?
- 30-60 mins of hospital arrival
- Within 12 hours of symptom onset
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
When is CABG an option for MI?
- Failed angioplasty
- Coronary anatomy that inhibits PCI
- Evidence of MI related septal rupture or mitral regurg
What is the treatment goal for NSTEMIs?
- Decreasing myocardial O2 demand
- Prevention of progression of plaque formation/rupture
What risks are associated with PCI (percutaneous coronary intervention) ?
- Vessel rupture/endothelial injury
- Bleeding
- Thrombosis
How long does reendothelialization take after balloon angio, bare metal stent placement, and drug eluting stent placement?
Balloon angio: 2-3 weeks
Bare metal stent: 12 weeks
Drug eluting stent: 1 year or more
What is Dual Antiplatelet Therapy (DAPT) ?
- ASA w/ P2Y12
What is the most significant predictor of stent thrombosis?
P2Y12inhibitor discontinuation
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 induced by BB?
Glycopyrrolate
Provides less tachycardia which you want to avoid in patients with ischemic heart disease
What pressor is preferred in patients who are beta blocked?
Vasopressin
Phenylephrine
Ephedrine
What components are worth 1 point on the Revised Cardiac Risk Index (RCRI) ?
more than 2 is considered elevated risk
What does 1 MET equal?
3.5 mL O₂/kg/min
How many METs preferred prior to surgery?
5 - climbing 1 flight of stairs, dancing, bicycling
What drugs can be given to blunt the SNS response to DL in patients with IHD?
- Lidocaine
- Esmolol
- Fentanyl
- Remifentanil
- Dexmedetomidine
Want to prevent tachycardia which worsens myocardial ischemia
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
