Arrhythmics Flashcards
Pathway of a heartbeat
- SA node
- R/L atria - atria contract
- AV node
- Bundle of His > ventricles
- right bundle branch
- left bundle branch
purkinje fibers
Arrthymia is caused
by a disruption somewhere in the conduction system:
-SA node can be firing at an abnormal rate or rhythm
-Scar tissue from a prior MI
another part of the heart may be acting like a pacemaker
Phase 0
rapid ventricular depolarization
-influx of Na = ventricular contraction (represented by the QRS)
Phase 1
early rapid repolarization
-Na channels close
Phase 2
influx of Ca and efflux of K
Phase 3
rapid ventricular repolarization
efflux of K = ventricular relaxation (T wave)
Phase 4
resting membrane potential is established
atrial depolarization occurs (represented by P wave)
QT prolonging drugs: antiarrhythmics
class Ia, Ic, III
QT prolonging drugs: anti-infectives
antimalarials, azole antifungals (all except Cresemba), macrolides, quinolones, lefamulin
QT prolonging drugs: antidepressants
SSRIs (escitalopram and citalopram), TCAs, mirtazapine, trazodone, venlafaxine
QT prolonging drugs: antimetics
5-HT3 receptor antagonists, droperidol, metoclopramide, promethazine
QT prolonging drugs: antipsychotics
1st gen (haldol, chlorpromazine, thioridazine)
second gen (ziprasidone)
QT prolonging drugs: oncology medications
ADT (leuprolide)
TKI (nilotinib)
Oxaliplatin
QT prolonging drugs: other
cilostazol, donepezil, fingolimod, hydroxyzine, loperamide, methadone, ranolazine, solifenacin, tacrolimus
Class I
Disopyramide, Quinidine, Procainamide
-pro-arrhythmic
Class Ib
Lidocaine, Mexiletine
-pro-arrhythmic
Class Ic
flecainide, propafenone
-pro-arrhythmic
Class II
BB
-slow ventricular rate in AF
Class III
dronedarone, dofetilide, sotalol, ibutilide, amiodarone
Class IV
Verapamil, diltiazem
Way to remember classes of antiarrthymics
Double Quarter Pounder
Lettuce Mayo
Fries Please!
Because
Dieting During Stress is always
Very Difficult