Day 6.3 Cardio Flashcards
Types of lipids in cholesterol (?)
LDL (bad) HDL (good) VLDL IDL Triglycerides
4 signs of hyperlipidemia
- Atheromas (plaq in bld vessel walls)
- Xanthomas (plaqs/nodules md of lipid-laden histiocytes in the skin, esp eyelids- xanthelasma)
- Tendinous xanthoma (lipid deposit in tendon, esp achilles)
- Corneal arcus (lipid deposit in cornea, non-specific- aka arcus senilis)
What are the 3 kinds of arteriosclerosis?
3 kinds:
Monckberg
AterioLOsclerosis
Atherosclerosis
Monckeberg
Calcification in the media (only) of the arteries, esp radial or ulnar arteries.
Usu benign
Pipestem arteries
Intima is NOT involved, so does not obstruct flow.
Arteriolosclerosis
Hyaline thickening of sml arteries
In essential HTN or in DM
Hyperplastic “onion skinning” in malignant HTN
Atherosclerosis
Fibrous plaqs and atheromas form in the intima of arteries - bad bc restricts flow.
Dz of elastic arteries and M/Lg muscular arteries.
Risk factors for atherosclerosis
Smoking HTN DM Hyperlipidemia Fam HX
Pathway of progression for atherosclerosis
Endothelial cell dysfn leads to macrophg and LDL accumulation. Foam cells form, cause fatty streaks. There is smooth musc cell migration (involving PDGF and FGF-beta), resulting in a fibrous plaq. This leads to complex atheromas.
Where is atherosclerosis usually located?
From most common to least: Abd aorta (can lead to AAA) Coronary artery Popliteal artery Carotid artery
What is an aneurysm? What is AAA?
Aneurysm - widening of blood vessel bc it’s weak.
AAA - abd aortic aneurysm. monitor closely and when it gets to 5cm, surgery. If it ruptures will have massive bleed in belly.
Symptoms of atherosclerosis
Usu asympt
Can have angina, claudication (angina in legs)
Complications of atherosclerosis
Aneurysms, ischemia, infarct, peripheral vascular dz, thrombus, emboli
What drugs are used to treat atherosclerosis?
The lipid lowering agents: HMG coA reductase inhibitors Niacin Bile acid resins (not common) Cholesterol absorption blockers Fibrates Omega 3 FA (fish oil, flaxseed)
HMG-coA reductase inhibitors
Effect, MoA, Side effects
Lovastatin, Pravistatin, Simvastatin, Atorvastatin, Rosuvastatin
Main effect is to decrease LDL
(Also raise HDL slightly and lower TG slightly)
MoA: inhibit cholesterol precusor mevalonate
SEff: hepatotoxicity, rhabdomyolysis
Niacin
Effect, MoA, Side effects
Drug of choice to increase HDL
also lowers LDL and TG
Inhibits lypolysis in adipose tsu and reduces hepatic VLDL secretion into circulation
SEff: red flushed face (decreases w longterm use or w aspirin), Hyperglycemia (acanthosis nigricans skin hyperpigmt), Hyper uricemia (worsens gout)
Bile acid resins
Effect, MoA, side effects
Cholestyramine, coestipol, colesevelam
Decreases LDL
also slightly increases HDL and slightly (bad) increases TG
Prevents intestinal reabs of bile acids, so liver must use up cholesterol to make more
Side eff: pts hate it- tastes bad, GI discomfort. decreased abs of fat-sol vit (ADEK). cholesterol gall stones.
What can Cholestyramine be used for?
To bind C. diff toxin and reduce toxin load.
Chlosterol absorption blockers
Effect, MoA, Side eff
Ezetimibe
Decreases LDL
Prevents cholesterol reabs at sml intest brush border.
Side eff: can actually mk plaq thicker. not really used.
Fibrates
Effect, MoA, Side eff
gemfibrozil, clofibrate, bezafibrate, fenofibrate
Decrease triglycerides (a lot)
Also decrs LDL, incrs HDL
They upregulate LPL to increase TG clearance.
Side eff: myositis + hepatotoxicity (so DON”T combo w statins usu), cholesterol gallstones
Omega 3 FA
Effect, side eff
Decreases TG
Can also reduce severity of rheumatic dz; decreases risk of arrhythmias in pts w heart dz
Side eff: smells. need to give a LOT to get effect.
Which is more imp to treat first: high LDL or high TG?
Treat high TG first, bc they can cause acute pancreatitis, which can be fatal
Aortic dissection
Longitudinal intraluminal tear forming a false lumen.
Assoc w HTN or cystic medial necrosis (Marfan’s)
Tearing chest pain radiates to scapula/back
CXR shows mediastinal widening
False lumen occupies most of the descending aorta.
Can result in aortic rupture and death.
Rx for aortic dissection
Type A (before subclavian)- more dangerous, prob need surgery Type B (after subclavian): give B-blockers (reduces overall BP, plus reduces slope of rise of BP)
4 manifestations of ischemic heart dz
Angina (stbl, unstbl, prinzmetal)
MI
Sudden cardiac death
Chronic ischemic heart dz
Angina
CAD narrowing more than 75% (is less usu don’t have sympt)
Stable: mostly 2ndary to atherosclerosis
ST depression on EKG (retrosternal chest pain w exertion)
Unstable/Crescendo: Thrombosis but no necrosis. ST deprsn on EKG (worsening pain at rest, w v little exertion)
Prinzmetal angina: occurs at rest, but secondary to coronary artery spasm.
see ST elevation (!!) on EKG- means severe ischemia.
Rx for Prinzmetal angina
Ca2+ chnl blocker- dihydropyridine (aka works at vessles) like nifedipine
MI
usu acute thrombosis d/t coronary artery atherosclerosis
results in myocyte necrosis
if complicated, leads to sudden cardiac death
Sudden cardiac death
Death from cardiac causes w/in one hour of onset of sympt
Most often d/t lethal arrhythmia (e.g. V-fib)
Chronic ischemic heart dz
Progressive onset of CHF over many years d/t chronic ischemic myocardial dmg
5 deadly causes of chest pain
Aortic dissection Unstable angina MI Tension pneumothorax Pulmonary embolus
Most common cause of non-cardiac chest pain?
GERD
also esophageal spasm, msk, costochondritis
Acute onset of dyspnea, tachycardia, and confusion in a hospitalized pt
Pulm Embolism (classic for hospitalized pts)
What is costrochondritis?
Chest pain where ribs insert into sternum, often d/t coughing.
Sternal pain
Rx NSAIDs
Sharp pain lasting hrs-days that is kinda helped by sitting fwd
Pericarditis
Goal of anti-anginal therapy
Reduce myocardial O2 consumption (MVO2) by decreasing one or more determinants of MVO2. They are: EDV BP HR Contractility Ejection time
What are the drugs used in anti-anginal therapy?
Nitrates, Beta-blockers, or the two in combination.
CCBs-
Nifedipine has similar effects as Nitrates
Verapamil has similar effects as Beta-blockers
Do nitrates and beta-blockers affect preload or afterload?
Nitrates- decrease preload (decrs EDV)
Beta-blockers- decrease afterload (decrs BP)
How is EDV affected by nitrates and b-blockers?
Nitrates decrease preload, so they decrs EDV
B-blockers decrease afterload, so they increase EDV
N+BB has no effect or decreases EDV
How is BP affected by nitrates and b-blockers?
Nitrates decrs preload so they decrs BP
B-blockers decrs afterload so they decrs BP
Together they decrs BP a lot
How is contractility affected by nitrates and b-blockers?
Nitrates decrease preload, but there is a reflexive response to the decrs in BP, so contractility is increased.
B-blockers decrease contractility
N+BB has no effect
How is HR affected by nitrates and b-blockers?
Nitrates decrease preload, but there is a reflexive response to the decrs in BP, so HR is increased.
B-blockers decrease HR
N+BB has decreases HR
How is ejection time affected by nitrates and b-blockers?
Nitrates decrease preload, so they decrs ejection time.
B-blockers decrease afterload, so they increase ejection time.
N+BB has no effect
How is overall MVO2 affected by nitrates and b-blockers?
Nitrates decrease preload, so they decrs MVO2.
B-blockers decrease afterload, so they decrs MVO2.
N+BB acts to very much decrease MVO2 - this is the goal.
If you add an ACE inhibitor, it will reduce it even more!
What 3 drugs are given together to reduce MVO2?
Nitrates, B-blockers, ACE inhibitors
What B-blockers are contraindicated in angina?
Pindolol and acebutolol- they are partial Beta-agonists.
MI: which coronary arteries are most likely to be occluded?
LAD > RCA > CFX
Sympt of MI
diaphoresis, naus/vom, severe retrosternal pain, pain in L arm and/or jaw, SoB, fatigue, adrenergic sympt (tachycardia)
During what time period is myocardial ischemia reversible?
Up to 20-40 min. After that, dmg is permanent.
MI Day 1
Artery is occluded, infarct occurs.
Dark mottling of infarcted tsu; pale w tetrazolium stain
Risk for arrhythmia
No visible chg by light microscopy in first 2-4 hrs
Contraction bands visible after 1-2 hrs
Early coag necrosis after 4 hrs
Rls of contents of necrotic cells into bloodstream (CK-MB, Troponin I, CPK, myoglobin) and beginning of neutrophil emigration
MI 2-4 Days
Hyperemia in infarcted tsu
Risk for arrhythmia (Arrhythmia is most common complication! Keep K+ >4 and Mg2+ >2)
Tsu surrounding infarct show acute inflam (see neutrophils)
Dilated vessels (hyperemia- redness)
Neutrophil emigration
Musc shows extensive coag necrosis
MI 5-10 days
Hyperemic (red) border w central yellow/brown softening. Max yellow and soft at by 10 days
Risk for free wall rupture; tamponade; papillary musc rupture; IVseptal rupture (all d/t macrophgs having degraded imp structural components)
Outer zone (See ingrowth of granulation tissue)
MI >10 days
Artery recanalized (at 7 wks) Infarcted tsu is grey/white
Risk for ventricular aneurysm- the scar tsu doesn’t contract. Over time it starts to bulge.
Contracted scar is complete
LAD occlusion results in which type of MI?
Anterior wall MI