Antiarrhythmic Flashcards
2nd class antiarrhythmics are
1st and 2nd gen BAB
4th class antiarrhythmic are
Verapamil and diltiazem (non dihydropiridine calcium channel blockers)
1class antiarrhythmic are
Procainamide1A,1B- lidocaine, 1C-ethacizine,propafenon, flecainid
Prcainamide has
cholinolytic activity
Ethacizine has class
4 property
Propafenon has both
Class 2 and 4 property
Flecainid has
Class 3 property
Class 3 antiarrhythmic agents are
Amiodarone, sotalol, vernakalant
Amiodarone class 3 has properties of
Class 1a,2 and 4
Sotalol class 3 has alo property of
Class 2
Vernakalant class 3 has also property of class
1b
Non classified antiarrhythmic agents are
Magnesium sulphate, Atropine, Digoxin, epinephrine
Phase 0 depolarization of SA node and AV nodeis provided by
Calcium influx
Phase 3of repolarization is provided by
K outflux
Phase 4 of slow depolarisation is provided by
Na influx through HCN channel and calcium influx
Arrythmia is defined as
Change in location of impulse origin ,change in HR and change in rhythm, conduction disturbance
Norm HR
55 to 80
Batmotropy
Ability to excite in response to stimulus
Dromotropy
Ability to conduct from one cell to other
Hemodynamics means
Providing rhythm and frequency control
Class 2 and 4 of antiarrhythmic inhibits
Phase 0 and 4 calcium influx in SA and AV
Class 3 inhibits
K outflux in phase 3 of CM
Class 1b and class 1c inhibits
Phase 0 Na influx in CM
Class 1a inhibits
CM in phase 0 Na influx and in phase 3,K outflux
Except 1b all others are used in
Supraventricular arrythmia
Except class 4 and vernakalant all others are used in
Ventricular arrythmia
For all 1a in ECG
Increase in QRS duration and QT increase
For all 1b class in ECG
Qt decrease
For. Al class 1c in ECG
QRS duration increase
1a and 1c has more affinity to
Open na channel than inactivated
Dissociation kinetics of drugs in na channels
1b faster than 1a faster than 1c
SE of Procainamide1A
Hypotension, lupus erythematous syndrome,TdP
Class 1 a has
Pro arrythmia effect(exacerbate or create new arrythmia)
Lidocaine doesn’t change QRS duration, because of
Fast DK
Lidocaine use
VA
Lidocaine has first pass metabolism,it has SE
CNS toxicity
Class 1 c use
SVA including Afib
SE of class 1 c
Heart failure
Class 3 effect on ECG
QT interwal prolongation
Amiodarone changes in ECG
Prolonged QRS,RR I,PRi,,QT i
Use of amiodarone
SVA(including Afib),VA
SE of amiodarone
Hypo or hyperthyroidism, pneumofibrosis, photo toxicity and hepatotoxicity, blue skin pigmentation (smurf skin), corneal deposition, rarely Tdp
Amiodarone is structurally similar to
Thyroxine
Amiodarone has long T1)2of
50 days and large distribution volumes
Amiodarone which is lipid soluble accumulates in
Liver ,muscle,lung,skin,fat
Acute overdose of amiodarone cause
Bradyarrythmia and hypotension
Chronic overdose of amiodarone cause
Bradyarrythmia, ventricular arrythmia, pulmonary toxicity, hypothyroidism etc
Treatment of amiodarone toxicity
QRS prolongation, bradyarrythmia and hypotension can be treated by sodium bicarbonate (reverse cardiac depression),Treat Torsades de pointes with magnesium
Use of vernakalant
Acute Afib
SE of vernakalant
Hypotension and bradycardia
Use of BAB in arrythmia
Frequency control of SVA and VA treatment
Magnesium sulphate action
Reduction of calcium inflow in ventricular cardiomyocyte
Magnesium sulphate use
TdP treatment
Atropine use
Sinus bradycardia and AV node block
Epinephrine use
CPR
Digoxin use
SVA
