Unit 2 Day 2 (Wednesday 4/8) Flashcards
Qualities of Normal Endothelium
- anti-inflammatory
- anti-thrombotic
- vasodilatory
- plays large role in mechanisms of ischemia
Stroke
- Common mechanism: Atheroembolization from carotid bifurcation lesion
- Source: lesion does not need to be obstructive (<70% diameter reduction)
- Ophthalmic artery
- Common mechanism: Thromboembolization from L atrial appendage in setting of A fib
Coronary Artery Disease (MI, Angina)
- Myocardial infarction and chronic stable angina are both manifestations of CAD
- However, vascular pathology is different
- MI – ruptured plaque, in-situ thrombosis, not necessarily obstructive prior to rupture
- Angina – stable, obstructive (>70% diameter reducHon) lesion
Myocardial Infarction- 2 Types
- Not all the same severity
- non occlusive embolus- stabilize with anticoagulation and vasodilators
- occlusive embolus- clinical emergency, recanalize
Peripheral Artery Disease
-Claudication and acute limb ischemia are manifestations of PAD
-However, underlying endothelial pathology differs
-Claudication: obstructive (>70% diameter reduction),
stable plaque
-Acute limb ischemia: acute event obstructs blood flow without prior development of collaterals, and could be atheroembolization or thromboembolization - rarely in-situ thrombosis
Venous Vs. Arterial Thrombosis
-Venous Thrombosis Fibrin rich RBC Areas of stasis Genetic predisposition Environmental predisposition Treated with anticoagulation
-Arterial Thrombosis Platelet rich Plaque rupture Areas of high flow Atherosclerosis trauma APLA Focus more on antiplatelet therapy
Vasospastic Disorders
- Raynaud’s (primary vs secondary)
- Pernio
- Erythromyalgia
- Acrocyanosis
- Dysfunctional endothelium involved but not necessarily thrombosis or atherosclerosis
Acute Coronary Syndromes
- what is it: unstable angina, NSTEMI, STEMI
- causes: atherosclerotic plaque rupture with thrombus formation as result
- pathophys: inflammation, risk factors (diabetes, hyperension, hyperlipidemia, tobacco)
NSTEMI
-non ST segment elevation MI
-partial coronary vessel occlusion with myocardial necrosis
-EKG: ST depression
-tx: halt thrombotic process from completely occluding artery by giving anticoagulant (unfractionated heparin, low-molecular weight heparin, fondaparinux) and antiplatelet ( P2Y12 inhibitors (clopidogrel, prasugrel, ticagrelor), GIIb/IIIa inhibitors
PLUS Aspirin) agents. If hemodynamically stable, also consider beta blockers or nitrates to dec. O2 demand
STEMI
- ST segment elevation MI
- complete vessel occlusion
- EKG: ST elevation
- tx: if artery can be opened in 90 min, go to cath lab to mechanically open, if not consider fibrinolytics. Also consider beta blockers or nitrates to decrease O2 demand
Unstable Angina (UA)
-partial coronary vessel occlusion, escalating symptoms, without myocardial necrosis
-discomfort which is new in onset or is increased in duration, frequency or intensity with less exertion or at rest compared to previous episodes of discomfort
-EKG: ST depression
-tx: halt thrombotic process from completely occluding artery by giving anticoagulant (unfractionated heparin, low-molecular weight heparin, fondaparinux) and antiplatelet ( P2Y12 inhibitors (clopidogrel, prasugrel, ticagrelor), GIIb/IIIa inhibitors
PLUS Aspirin) agents. If hemodynamically stable, also consider beta blockers or nitrates to dec. O2 demand
CK-MB
- biomarker
- less sensitive than TnI
- time to initial elevation: 4-6 hrs
- time to peak elevation: 18 hrs
- time to return to normal: 2-4 days
Troponin I
- biomarker
- time to initial elevation: 4-6 hrs
- time to peak elevation: 12 hrs
- time to return to normal: 3-10 days
Stable Angina
- present when there is increased demand for myocardial oxygen in a reproducible fashion
- due to atherosclerotic obstructing plaque
- relieved by rest
- exacerbated by large meals, exposure to cold, smoking
- typically pain last a few minutes, not seconds or hours
- at least 2 months in duration without inc. in frequency or intensity
- usually relieved in 1-3 min by sublingual nitroglycerin
- tx: primary: aspirin, statin, stop smoking, and tx hypertension or metabolic syndrome if present
- tx: secondary: beta blockers, nitrates, angioplasty or bypass surgery, ranolazine, long acting nitrates, CCBs
Stable Angina
-present when there is increased demand for myocardial oxygen in a reproducible fashion
