Cardiac Pt 2 Flashcards
What do antiangial drugs treat
Symptoms cause by inadequate coronary blood flow associated with vasospasms/stress/exercise/athersclerosis
Examples of antiangials and MOA
Propranolol- beta antagonist that decreases cardiac output. Decreases the work of the heart and decreases myocardial anoxia
Nitroglycerin- stimulates NO production, induces coronary vasodilation and increases oxygen delivery to the myocardium
Why is sublingual forms of nitroglycerin ineffective when swallowed?
High first pass effect. Better to bypass the stomach
Treatment for cardiac arrest
Epinephrine or isoproterenol are b1 agonist in cardiac tissue increase sns activity of SA node that can induce myocardial systole (contractions)
What reduces the spread of necrosis from myocardial infarctions
Treat with fibrolytic drugs that dissolve blood clots.
Which drugs serve as enzymes that catalyze plasmin formation within a clot that leads to fibrolysis
Tissue plasminogen activator (tpa), streptokinase, urokinase
Flow of plasminogen to reduce anoxia and spread of necrosis
Plasminogen to plasmin, catalyzes the depolymerization (scaffolding) of fibrin network within a clot, fibrolysis, reinstates blood flow, and reduce anoxia and spread of necrosis
Amiodarone
Class iii potassium channel blocker. Used to control a fib and v tach caused by ectopic foci (pacemakers outside of SA node) aka beat is being made outside of SA node. its effects are mediated by inhibition of sodium and calcium channels
The direction of ion movement across membranes during an action potential is influenced by what?
The concentration gradients of ions and membrane permeability
Phase 0 cardiac action potential
Fast sodium channels open and rapid influx of sodium. Rapid depolarization (systole)
Phase 1 cardiac action potential
Sodium channels close, potassium channels start to open.
Phase 2 cardiac action potential
Calcium channels open, potassium channels are still open
Phase 3 cardiac action potential
Calcium channels close, potassium still open
Phase 4 cardiac action potential
Potassium channels finally close.
Amiodarone toxic side effects
Lung fibrosis, thyroid damage (amio has iodine), liver damage
What happens when the enzyme that break down bradykinin is inhibited by the ace inhibitor
Bradykinin accumulates along the respiratory airway and stimulates an inflammatory like condition that makes a chronic cough
Good side effect of accumulation of bradykinin
Stimulates myocardial fibrolysis that reduces progression of cardiac remodeling which prolongs the life of patients with cardiac failure
What are first line treatments of patients with symptoms of fluid overload
Diuretics (thiazide/loop) combined with ace and arb
Tolvaptan
Oral vasopressin (antidiuretic hormone) antagonist that is used to treat hyponatremia/hypervolemia is secondary to end stage heart failure
Why do you need to be careful with dosing for metoprolol in heart failure
May block heart too much that can make heart failure worse
Ivabradine
Selectively inhibits a unique sodium potassium ion channel in the SA node of the heart that reduces pacemaker activity and lowers heart rate
Digoxin and other cardiac glycosides
Produce a positive inotropic effect on the myocardium which increases cardiac output that helps tissue perfusion
Entresto combo med
Neprilysin inhibitor (sacubitril) *it is not ace inhibitor * and angiotensin ii receptor blocker ARB (valsartan)
Neprilysin is an enzyme that breaks down what
Natriuretic peptides like ANP
Potent natriuretic and vasodilators properties, Inhibit rass, reduce sympathetic drive, have antiproliferative and antihypertrophic effects
Natriuretic peptides have
Hdl
Good cholesterol - removed cholesterol from the walls
LDL
Bad, cling onto arteries walls
Do we make cholesterol endogenously?
Yes through acetyl CoA. Cholesterol used to make steroids
Exogenous cholesterol is from what?
Diet- animal proteins
Hyperlipidemia is associated to which cholesterol
LDL
Hyperlipidemia is associated to which cholesterol
LDL
Lovastatin
Hepatic 3 hydroxy 3 methyl glutarate (HMG) coenzyme e reductase inhibitor which suppresses lipoprotein synthesis
Inhibits hepatic triglyceride synthesis thus suppressing lipoprotein synthesis
Gemfibrozil
Inhibits hepatic triglyceride synthesis thus suppressing lipoprotein synthesis (increases production of hdls that activate reverse cholesterol transport from peripheral vascular beds )
Gemfibrozil
Niacin
Triglyceride lipase inhibitor in adipose tissue that reduces hepatic triglyceride synthesis and lipoprotein synthesis
Ion exchange resin that binds to bile salts and results in their elimination through the feces. Hepatic production of cholesterol is diverted from production of lipoproteins to bile salts
Cholestryamine
Ezetimibe
Inhibitor of cholesterol transport protein, blocks absorption of dietary cholesterol and cholesterol that enters the entrohepatic circulation
Why might the combo of ezetimibe and simvastatin be expected to have a great effect on blood levels of ldl then a mono therapy with a hmg-coa reductase inhibitor?
Working on two different systems.
Evolocumab (repatha)
Enzyme inhibitor of proprotein convertase subtitlisin/kexin type 9 ( PCSK9) that controls destruction of LDL receptors ( LDLRs) on many tissues including the liver
What hyperactive gene causes hypercholesterolemia that leads to early death from CAD
PCSK9
Circulating PCSK9 proteins bind to and control the destruction of ______ that arises in the uptake and metabolism of ____ _____ in the liver
LDL receptors (LDLRs)
LDL cholesterol
Aspirin
Inhibits cyclooxygenase ( COX) which reduces thromboxane production (reduce platelet adhesion)
ADP receptor antagonist on platelets
Clopidogrel (plavix)
Tirofiban
Serves as an antagonist to the GPIIb/IIIa platelet receptor which blocks platelet binding to fibrinogen in an area of platelet plug formation
Protease activated receptors (par-1) mediate thrombins effects on platelet aggregation.
______ is a selective inhibitor of par-1 on platelets
Vorapaxar (zontivity)
How is intrinsic pathway activated ?
Internal damaged tissues ex. sepsis, inflammation
How is extrinsic pathway activated
A trauma ex, fall; injury
Warfarin facts
Inhibits vitamin k depending clotting factors. (Inhibits 7 on extrinsic, 9, 10 on intrinsic) Onset time is delayed, limit vitamin k rich foods, need blood testing inr/pr, dose adjusted to blood test, antidote is available
Dabigatran
Reversible inhibition of thrombin, onset time is rapid (hours), few food drugs interactions, no blood testing, fixed dose, less bleeding
Fibrolytic drugs like TPA are known _____ ______ . They are used to dissolve ______ blood clots
Clot busters, Pre-formed
Heparin
Inhibit the functions of the clotting cascade in the blood which prevents blood clot formation, treats pulmonary embolisms, DVT
