Block II: Antiarrythmics Flashcards
What constitutes a prolonged QTC interval and may bar you from initiating an antiarrythmic?
M > 450
F > 470
What drugs belong to class Ia?
- quinidine
- procanimide
- disopryramide
Double
Quarter
Pounder
Where do class Ia drugs exert their effects primarily?
Supraventricular/ventricular arrythmias
What ion channel do class Ia drugs affect?
Na+
What drugs are class Ib
- lidocaine
2. mexiletine
where do class Ib drugs exert their effect?
ventricular arrythmias
what ion channel do class Ib drugs alter?
Na +
Where to BB exert their effects?
supraventricular, ventricular
what ion channel to BB block
Ca+
What are class Ic drugs?
- flecaninide
2. propfanone
where do class Ic drugs exert their effects?
supraventricular, ventricular
what ion channel do class Ic drugs exert their effects on?
Na+
Where do non-DHP CCBs exert their effects?
termination SVT, slow rapid Afib or Aflutter
what drugs belong to class III
- amiodarone
- Dofetilide
- dronedarone
- sotalol
- ibutilide
What drugs belong to class II
BB
where do class III drugs exert their effects?
any tachycardia
what ion to class III drugs work on?
K+
what are class IV drugs?
Non-DHP CCB
Quinidine belongs to what class?
Ia (supravent/ventricular Na+ block)
Procanimide belongs to what class?
Ia (supravent/ventricular Na+ block)
Disopyramide belongs to what class?
Ia (supravent/ventricular Na+ block)
Lidocaine belongs to what class?
Ib ventricular, Na+ block
Mexiletine belongs to what class?
Ib ventricular, Na+ block
Flecanide belongs to what class?
Ic supravent, vent Na+ block
Propafenone belongs to what class?
Ic supravent, vent Na+ block
How can you remember class one drugs?
Ia: Double- Disopyramide Quarter-Quinidine Pounder- Procanimide Ib: Lettuce-Lidocaine Mayo-Mexiletine Ic: Flecainidie- fries Please- Propafenone
What class does Amiodarone belong to?
III, tachyarrythmias K+
What class does dofetilide belong to?
III, tachyarythmias, K+
What class does Dronedarone belong to?
III, tachyarythmias, K+
What class does sotalol belong to?
III, tachyarythmias, K+
What class does Ibutalide belong to?
III, tachyarythmias, K+
What class does verapamil belong to?
IV, termination SVT and slowing rapid Afib/flutter
What class does diltiazem belong to?
IV, termination SVT and slowing rapid Afib/flutter
What is the MOA class Ia
Prolong phase 0, rapid depolarization phase, and widen QRS
Moderate Na+ channel blocker may increase ERP (refractory period)- prolongs action potential
-risk for secondary arrythmia (dose dependent)
Disopyramide is a strong []
anticolingergic
Quinidine is a []
anticholinergic
Procanamide may cause []
lupus like syndrome
MOA class Ib drugs
shorten refractory period, shorten AP, and shorten QTc
Class Ib drugs are only used for
ventricular arrythmias
What is mexilteines dosage limitation
severe nausea
MOA class Ic drugs
NO change refractory period, QTc, no risk secondary arrythmias
what is the mc use Ic drugs
atrial arrythmias or life threatening ventricular
What is the MOA class II drugs
BB
Block adrenergic stimulation (decrease HR, CO, Force contraction)
What is the use Class II drugs
BB
- terminate re-entrant arrythmia at AV node
- control ventriculat rate in afib/flutter
- exercise tachycardia
What BB are used to treat arrythmias?
- metoprolol
- propanolol
- esmolol
What is the MOA class III drugs
K+ channel blocker prolong repolarzation (phase 3) AP -halt exit K+, prolong repolarization, refractoriness, an QT interval
How are class III drugs used
to control tachyarrythmias
SE class III drugs
may be pro arrythmic
what is the MC antiarrythmic?
amiodarone
MOA amiodarone
Class III: K+ blocker, some Na+ activity, alpha block, and beta block activity
What is the use amiodarone
prevent recurrent ventricular arrythmias, sinus rhythm w/ paradoxical afib,
SE amiodarone
EXTENSIVE, may cause neuropathies
What is the MOA Sotalol
Class III
NOS BB Ca2+ channel effective
Pearl on Sotalol
check baseline EKG!! to eval. QTc
and titrate accordingly
don’t use if over 500
Use Ibutalide
class III
IV only
Afib/flutter
pearl ibutalide
SULFONAMIDE
*sulfa allergy
Use dofetilade
class III Afib/flutter
Pearl dofetalide
renal dose adjustment
Monitor EKG x3 days post intiation and 12 hrs post dose increase
use non-DHP CCB
Class IV
affect slow response myocardial tissue by blocking long Ca++ channels
Supraventricular tachycardia
RATE control afib/flutter
work in SA and AV node
Who should avoid diltiazem/verapamil
HF or decreased ventricular function
If a pt. has sinus bradycardia with symptoms of hemodynamic compromise, what is the tx of choise
Atropine
If a pt. has sinus bradycardia with symptoms of hemodynamic compromise and a likelihood or coronary ischemia, what is the treatment of choice?
Isoproterenol, dopamine, epi, dobutamine
What if a pt is hemodynamically compromised and is refractory to medical therapy
temporary pacing until pacemaker can be set
How are you treating a 1st degree AV block?
No tx
- eval meds, dc causative agents
- check lytes
How are you treating 2nd degree AV block
Pacemaker
How are you treating a 3rd degree Av Block
Pacemaker
Pts. showing symptoms of bradycardia and hemodynamic compromise must receive
atropine
How are you treating a pt. with hemodynamic compromise and suffering acute MI
Aminophylline
How are you treating Asystole
Epi
what should you run through in a PEA pt?
H’s and T’s
H: hypovolemia, H+ acidosis, Hypo/Hyper kalemia, Hypoxia, hypoglycemia, hypothermia
T: thrombosis, trauma, tension/pneumothorax, tamponade, toxines
How are you treating a PEA pt?
Epi (asystole)
Are PEAs shockable?
NO, shocking gets you in rythm, if no beat no rythm to fix
How are you treating a hemodynamically stable Vtach pt
IV procainamide, amiodarone, or sotalol
How are you treating a hemodynamically unstable Vtach pt?
Defibrillation
How are you treating a polymorphic Vtach pt. due to MI
BB
unless torsades!!!!
How are you treating a torsades pt?
Mg IV
D/c offending agent
How are you treating your Vfib patient?
SHOCK
How are you treating your SVT pt who is hemodynamically stable?
- vagal maneuvers, cold water, carotid massage
2. adenosine, BB, non-DHP CCB if all else fails
How are you treating your SVT patient who is hemodynamically unstable?
shock (DCC) direct cardio version
MOA Adenosine
slow conduction through AV node, interrupt re-entrant pathway, flatline x10 s
SE adenosine
flushing, HA, SOA
How are you treating acute Afib?
Rate control
BB, non-DHP CCB, digoxin
How are you treating Afib pts. long term?
- Rate control (easier, less SE)
vs. - Rythym (if sympomatic)
- stroke prevention
How are you treating Afib rate control and why?
if asypmtomatice, easier with less SE
- BB
- Non-DHP CCB
- Digoxin (can only be adjunct, only works when pt. at rest)
What is the rate goal Afib?
< 110 BPM if stable LV function
<80 BPM at rest
How are you treating afib ryhtm control and why?
If symptomatic, get rythm
- cardioversion, will need anticoag. post shock x 4 weeks.
will need antiarrythmic after schock too. - Dofetalide, Flecanide, Ibulilide, propafenone, amiodarone
If afib > [] hrs (or UK time), what is needed prior to shock?
48 hours, warfarin or DOAC x 3 weeks prior, 4 weeks after shock
*heparin if hemodynamically unstable
What is 1st line rythm maintenance in an Afib pt. with no structural heart defects?
- flecainide
- propafenone
- stoalol
What is 1st line rythm maintenance Afib with CAD
- dofetalide
2. sotalol
What is 1st line rythm maintenance in afib with HF
- amiodarone
2. dofetilide
What is second line Afib rythm maintenance
- amiodarone
- dofetalide
- catheter ablation
What is second line afib rythm maintenance if CAD
- amiodarone
2. cath ablation
what is second line afib rythm mainteneance if HF
amiodarone
what drug is category X
dronedarone
What drug is category D
amiodarone
[] anticoag is used if mechanical valves
warfarin
What CHADs is women req. anticoag
3
what CHADs in men req. anticoag
2
Dabigitran is a [] drug
factor IIa DOAC
Rivaroxaban is a [] drug
Factor Xa DOAC
How would you treat symptomatic PVCs
BB
Afib patients must be [] to be considered rate controlled
asymptomatic
What can cause pharmacologic cardioversion?
Dofetilide, flecainide, ibutilide, propafenone, amiodarone