Angina Flashcards
coronary artery partly blocked
reduced blood flow through narrowed arteries cannot meet increased oxygen demand
EKG: ST depression
Classic Angina
results from spasm of one of the largest arteries of heart
EKG: ST elevation
coronary angiography normal - no narrowing
Variant angina/ Prinzmetal angina
occurs when significant occlusion of coronary artery angina symptoms occur at rest might signal MI medical emergency EKG: ST depression
Acute coronary syndrome/ Unstable Angina
chest pain 5-10 min
nitrate relieves pain
plasma enzymes troponin, CPK-MB normal
Angina
chest pain > 20 min
nitrate does not relieve pain
Increase plasma enzymes troponin, CPK-MB
EKG: Q wave, ST upwardly convex elevation, T inverse
MI
Chest pain continues for days dull sit up & lean forward to relieve pain fever friction rub EKG: ST concave elevating WBC increases
Pericarditis (bacteria, virus)
release NO - activates guanylyl cyclase to form cGMP - dephosphorylates MLC leading to smooth muscle relaxation
reduce cardiac preload at lower dose
dilate artery at high doses
nitrates
nitrate given sublingually, IV, oral, ointment, slow release patch
Nitroglycerin
nitrate given sublingually & orally for chronic maintenance
isosorbide dinitrate
nitrate given orally for chronic maintenance
isosorbide mononitrate
ADR: severe headache, tolerance (tachyphylaxis) [drug holiday - Monday dz: re-sensitize], postural hypotension, methemoglobinemia
nitrates
Contraindications: w/in 24 hours of nitrates use can not use __________- severe hypotension, may lead to MI
Sildenafil
oppose action of adrenaline in heart, reduce work load of heart, helps prevent future angina, used in prophylaxis only
contraindications: prinzmetal angina
Beta blockers
both nitrate & K ch opener effects
stabilizes excitable cells near resting membrane potential
causes relaxation of smooth muscle (vasodilation)
decreases preload & afterload
dilates coronary artery
Nicorandil
treats chronic angina (limits size of ischemia & infarct area)
1. inhibits Na+ current and more Ca2+ excreted - less contraction
2. at high doses - pFOX inhibitor, shifts from pFOX to glucose oxidation
SE: Q-T prolongation
Ranolazine
phosphodiesterase type 2 inhibitor
decreases cAMP degradation
inhibits platelet & vasodilator
treats: leriche syndrome (leg intermittent claudication)
Cilostazol
other drugs: aspirin (prevent TXA2 production)
Clopidogrel
Abciximab (Gb2b3a inhibitor)
non selective CCB
causes long QT syndrome
blocks Na+ ch activity
Bepridil
CCB that prevent vasospasm in subarachnoid hemorrhage to prevent ischemic stroke complication
Nimodipine
Nicardipine
slows cardiac conduction
decreases HR & O2 demand
blocks P glycoprotein drug efflux transporter
reverses chloroquine resistance in malaria treatment
never combine with beta blockers
verapamil
mainly artery dilator
useful for treatment of variant angina
given with beta blocker to prevent reflex tachycardia
Nifedipine
slows cardiac conduction
decreases HR & O2 demand
specific coronary vasodilation effect relieving coronary vasospasm
useful in treatment for variant angina
Diltiazem
major action of nitrates on capacitance vessels (veins)
venodilation -> decrease preload (venous return) -> decrease cardiac work -> decrease oxygen requirement
