Term
state dependent blockade concept |
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Definition
antiarrhythmics have a higher affinity for channels in the activated or inactivated state because these are the channels most likely to be excessively stimulated (causing the problem). The channels at rest are not the problem. |
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Term
What is the common property of the Class I drugs? |
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Definition
to slow conduction in myocardial tissues in which conduction velocity is controlled by sodium channels
(so, myocytes) |
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Term
t/f: class IA are less effective and less well tolerated than drugs like amiodarone for prevention of AF |
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Definition
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Term
Class IA are CI in what condition? |
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Definition
left ventricular hypertrophy |
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Term
Which NA channel blockers are 2/3rd line therapy for long term treatment of atrial arrythmias?
(they are considered safe in patients with implantable defibrillator) |
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Definition
Class IA
quinidine, procainamide, disopyramid |
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Term
What is the first line treatment for Wolff Parkinson White syndrome? |
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Definition
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Term
Where are Class IB's greatest effects? |
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Definition
depolarized tissue where it depresses conduction |
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Term
Where does lidocaine (IB) soar? |
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Definition
arrhythmias associated with MI |
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Term
How do flecainide and propafenone work?
what are they used for? |
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Definition
most potent na channel blockers of class I
prolong the ap potential at faster rates??
suppress PVCs |
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Term
What are flecainide and propafenone CI in? |
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Definition
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Term
Flecainide and propafenone cause greater prolong of action potential duration at faster rates. Why does this matter? |
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Definition
Contributes to the efficiacy for a fib |
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Term
Which Class I drug is effective for suppressing PVCs? |
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Definition
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Term
What drugs are most effective in controlling arrhymias in patients:
1. surviving MI
2. Advanced heart failure with reducted ventrcular function
3. adjunctive therapy for implantable defibrilators |
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Definition
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Term
What are the three uses of beta blockers? |
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Definition
1. stop re-entrant arry in AV node
2. controle ventricular response rate in afib/aflutter
2. torsades with emotional stress |
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Term
Which class is better for suppressing ventribular ectopic depolarizations? I or II? |
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Definition
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Term
I am a selective beta 1 antagonist availiable for IV use only
half life less than 10 minutes
no ISA
I am useful in the rapid control of ventricular rate in patient with atrial flutter or fibrillation |
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Definition
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Term
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Definition
Amiodarone
analog of thyroid hormone |
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Term
What is amiodarone's MOA? |
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Definition
1. block sodium channels (phase 0 = decrease slope)
1. k channel block (phase III) |
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Term
When do you use Amiodarone? |
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Definition
ventricular arrhythmias
(v. tach, v fib)
off label: maintianing sinus rhythm in paroxysmal a fib |
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Term
Which is more pro-arrhythmic?
Class III (amiodarone) or Class I? |
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Definition
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Term
What cause the decreased TPR (afterload) following IV administration of amiodarone? |
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Definition
amiodarone's alpha and beta adrenergic antagonist effects
may be responsible for its antianginal effects |
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Term
Name the drug that causes these ADRs:
1. optic neuropathy
2. liver dysfuntion
3. thyroid dysfuntion
4. neuromuscular
5. photosensitivy
6. pulmonary fibrosis |
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Definition
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Term
What are the three main PK precautions we put on our study guide for amiodarone? |
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Definition
cyp 3a4 substrate
watch out for QT prolongation drugs
may increase risk of AV block with CCbs, Bblocker and Dig |
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Term
What drug is comparable to amiodarone but is safer? |
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Definition
dronedarone (due to iodine removal...but this causes more thyroid adverse effects)
it is less lipophilic and it's half life is only 15 hours as compared to ami |
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Term
Sotalol is the weirdo of the class III. What other class could it fit into? |
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Definition
Class II - beta blocker (low doses)
class III (high doses) |
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Term
should you take sotalol with food? |
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Definition
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Term
t/f: kidney function matters with sotalol |
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Definition
true
very important!!!!
because it is eliminated unchanged! |
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Term
If sotalol accumulated due to kidney issues what would be the possible outcome? |
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Definition
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Term
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Definition
1. asthma
2. heartblock
3. qt prolongation
4. uncompensated chf
5. CrCl < 40 |
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Term
sotalol must be initated in a setting with continuous ecg monitoring
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Definition
if QT>450 msec at baseline do not use |
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Term
When should you recheck your patient's QT after administering sotalol? |
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Definition
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Term
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Definition
1. other QT prolongers
2. CCBs
3. Beta blockers
4. Antacids
5. bile acid sequestrants
6. calcium |
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Term
Which drug rapidly converts patients with a fib or atrial flutter of recent onset (<90 days) to normal sinus rhythm?
What class does this drug belong to? |
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Definition
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Term
Which is worse, flutter or fibrillation? |
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Definition
fib is worse because it is unorganized
ibutilide is more successful on atrial flutter (50%) than a fib (30%) |
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Term
Ibutilide does what to the AP duration and acts on what channel (unique to class III)? |
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Definition
prolongs AP duration
increases sodium (slow) in, so the plateau phase is increase |
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Term
adverse effects of ibutilide? |
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Definition
torsades
av block
sustain ventr. tachy |
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Term
What drugs do ibutilide interact with? |
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Definition
class I (increases v tach or torsades)
QT prolongers (phenothiazine, TCA, FQ) |
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Term
What is the last class III drug?
ha (this is really strategic for memorizing purposes)
What is it used for? |
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Definition
dofetilide
to restore normal sinus rhythm in patients with a fib or flutter
to maintain NSR following conversion by other means |
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Term
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Definition
torsades
QT syndrome
QT interval > 450
renal impariment
HR < 50 bpm, bradycardia
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Term
t/f: dofetilide needs ECG monitoring |
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Definition
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Term
t/f: dofetilide should be dosed based on renal function. |
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Definition
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Term
Which CCBs are not used as antiarrh? |
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Definition
dihydropyradines
nifedipine |
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Term
What are the three drugs in the Class IV, that we are concerned with? |
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Definition
verapamil
diltazem
bepridil |
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Term
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Definition
l type channel blocker
decrease calcium current
decrease recovery (meaning increase refractory period)
increased frequency, then increased action
decreases conduction velocity thru AV node |
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Term
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Definition
contorl ventricular response rate in a fib or aflutter
diltiazem is oftern the DOC for this indication
also, reentrant supraventircular tachy involving the AV node |
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Term
What class does adenosine belong to? |
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Definition
TRICK question
it's misc
(nucleoside) |
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Term
What should you use to rapidly convert PSVT?
(paroxysmal supraventricular tachycardia) |
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Definition
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Term
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Definition
It increases the refractory period by increasin outward K in phase 3. Then it inhibits Cacium (because it decreases Camp), which decreases the slope in phase 0 and 4. |
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Term
What does theophylline and caffeine do to the dose of adenosine? |
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Definition
you must increase the dose |
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Term
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Definition
promotes clearance of adenosine...decrease the dose
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Term
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Definition
dig induced arry, torsades, acute MI
slows rapid signals from SA node |
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Term
digoxin is used for what? |
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Definition
control ventricular rate during chronic afib |
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Term
What wave represents the depolarization of the atria? |
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Definition
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Term
When does the signal get to the AV node? |
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Definition
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Term
What does the QRS represent? |
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Definition
depolarization of the ventricles |
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Term
t/f: all four classes decrease automaticity? |
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Definition
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Term
What effect on the ECG oes class IC have? |
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Definition
Increases QRS (depolarization) |
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Term
What effect do beta blockers have on the ECG? |
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Definition
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Term
What shows up on ECG with class III?
(ami and dofeilide) |
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Definition
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Term
What ECG changes occur with CCBs in nodal tissue?
non nodal? |
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Definition
nodal = increased PR (decreased HR)
non nodal = decreased QT |
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