Term
Match the following with the correct waves on an ECG.
Atrial depolarization, ventricular depolarization, ventricular repolarization |
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Definition
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Term
| What does the QT interval represent? |
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Definition
| ventricular depolarization to end of ventricular repolarization |
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Term
| During an action potential what ion channels are associated with phase 0,1,2,3, and 4? |
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Definition
0-Na
1- probably K?
2- Ca
3- K
4- K/Na pump |
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Term
| Differenetiate fast and slow APs. |
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Definition
fast have all phases and are found in the atria, ventricles, and purkinje fibers
Slow have no phase 1 or 2(kinda) and are found in the SA AV nodes |
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Term
| Pacemaker APs are slow or fast APs? |
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Definition
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Term
| Differentiate effective vs relative refractory periods |
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Definition
effective- no second ap can be generated
relative can have a second ap but it requires a greater stimulus to reach threshold |
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Term
| Differentiate parasympathetic and sympathetic influences on the nodes, which channels they use and overall affect on heart rate. |
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Definition
para-SA and AV nodes, decrease Ca, increase K, decrease heart rate
symp- SA only, increase Ca, increase HR |
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Term
| What are the two problems that cause arrhythmias? |
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Definition
impulse formation problems
impulse conduction problems |
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Term
| What are the two specific impulse conduction problems? |
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Definition
Conduction block(abnormal conduction)
Re-entry impulse excites area twice |
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Term
| Type 1 antiarrhythmics class |
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Definition
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Term
| Type 2 antiarrhythmics class |
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Definition
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Term
| Type 3 antiarrhythmics class |
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Definition
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Term
| Type 4 antiarrhythmics class |
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Definition
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Term
| What are type one used for? |
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Definition
local anesthetics
dont completely block otherwise you would die |
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Term
Drugs: Type 1A
affinity? causes what? |
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Definition
procainamide, disopyramide, quinidine
(PDQ)
medium affinity
decreases upstroke of AP (qt prolongation) so if 2nd ap comes while still going no heartbeat |
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Term
| What is the name for QT prolongation? |
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Definition
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Term
Drugs: Type 1B
affinity? causes what? affect normal tissue? |
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Definition
lidocaine, mexiletine
low affinity for Na channel
decreases slope of phase 4(shifts end left)
decreases automacity
only affects depolarized tissue |
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Term
Drugs: Type 1C
affinity? causes what? problem with? |
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Definition
propafenone, flecainide
high affinity for Na Channel
decrease in conduction
very Arrhythmogenic |
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Term
| Which of the Type ones needs to be very short term use? |
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Definition
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Term
| Which two of the type ones also blocks K? |
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Definition
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Term
Drugs: Type 2
affect, sa or av?, treat? |
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Definition
propranolol, metoprolol, esmolol
decrease sympathetic
SA much greater
decreases tachycardia |
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Term
| Which type is good for reentry circuits? |
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Definition
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Term
Drugs: Type 3
causes, caution? |
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Definition
amiodarone, sotalol, dofetilide, ibutilide
delays repolarization
arrhythmogenic |
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Term
| Which two types cause prolonged qt? |
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Definition
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Term
| Which phases does type 3 affect? |
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Definition
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Term
Drugs: Type 4
sa or av, three affects |
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Definition
verapamil, diltiazem
sa and av
slowed conduction
prolonged refractory period
slow ventricular response |
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Term
| What is the safest type? little arrhythmogenic activity |
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Definition
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Term
Adenosine
ion channel? where are channels found? Net effect? |
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Definition
increases K channel
atria, sa/av
decreased AP duration
decreased automacity |
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Term
Digoxin
type of effect? sa or av? effect on Ca and K channels? Net effect? |
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Definition
vagotonic effects
both sa/av
decrease Ca
increase K
Decreases AP formation |
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Term
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Definition
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Term
| What is important in the treatment of angina? |
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Definition
| you want to reduce demand of oxygen by the heart in relation with the supply |
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Term
| What are the consequences of angina? |
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Definition
wall thickening and thinning
hypotension
decreased contractility
myocardial damage |
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Term
| What are the four major factors affecting heart oxygen demand? |
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Definition
heart rate
preload
afterload
contractility |
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Term
| Describe how contractility is dependent on preload and afterload |
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Definition
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Term
| What are the three types of angina? |
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Definition
fixed-stable occlusion (artery mostly blocked)
spasm- occlusion/damage (artery swells?)
unstable- thrombosis/spasm (complete blockage) |
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Term
| Which type of angina is from a complete occlusion? |
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Definition
unstable
takes 1/3 blood from heart |
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Term
| What are the three types of drugs for angina? |
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Definition
Nitrates
beta blockers
Ca blockers |
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Term
| What are the nitrates for angina? |
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Definition
| Nitroglycerin and isosorbide |
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Term
| What are the nitrates mech of action? |
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Definition
MAO cleaved and forms NO
increases guanylate cyclase
increases cGMP
vasorelaxion |
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Term
| Differentiate low dose vs high dose nitrates |
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Definition
low dose- venodilation, decreased preload and o2 consumption
high dose- arterial and venous dilation |
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Term
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Definition
vessel growth to try and replace coronary blood supply in angina patients
not very effective |
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Term
| Do nitrates dilate the new blood vessels from coronary steal? |
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Definition
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Term
| Beta blockers for angina? |
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Definition
propranolol
metoprolol
atenolol
acebutolol |
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Term
| What is the mech of action of angina beta blockers? |
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Definition
| block beta1 which decreases heart rate which decreased oxygen consumption |
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Term
| Ca blockers for angina? Effects? |
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Definition
verapamil, amlodipine, nifedipine, nicardipine, diltiazem
decrease contractility and slight decrease in heart rate which leads to less oxygen consumption |
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Term
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Definition
| decreases intracellular Na which affects Na dependent Ca channels which decreases heart contractility which decreases o2 demand |
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Term
Ivabradine
mech? effect? ADR? |
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Definition
decrease Na in SA node which decreases APs which decreases heart rate which reduces o2 demand
adr-enhanced visual brightness(luminous phenomenon) |
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Term
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Definition
drugs that ramp up heart
for CHF |
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Term
| What are the three types of inotropes? |
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Definition
cardiac glycosides
beta agonists
phosphodiesterase inhibitors |
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Term
| Cardiac glycoside drug? mech? effect? adr? |
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Definition
digoxin
decreases na/k atpase which slightly increases Na which alters driving force for Na/Ca exchanger which increases Ca in SR which increases contraction
adr- hallucinations |
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Term
| beta agonists? *inotropes |
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Definition
| dopamine, dobutamine, isoproterenol |
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Term
Dopamine
Low, intermediate, high dose? |
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Definition
low- vasodilation by stimulating dopamine receptors
intermediate(2-5mg)- increase inotropy/contractility by beta agonist
high- vasoconstriction by alpha stimulation |
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Term
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Definition
| beta 1 predominates and increases inotropy |
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Term
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Definition
nonselective beta agonist
increase in inotropy and chronotropy
decrease PVR |
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Term
Phosphodiester inhibitors
effects? |
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Definition
amrinone and milrinone
increase contractility
increase heart relaxation
increase arteriole dilation(only new blood vessels?) |
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