Anti-arrhythmics

Question 1

use of anti-arrhythmics

Answer 1

restricted to dangerous/symptomatic arrhythmias –> Vtach, rapid afib

Question 2

Class I/II MOA

Answer 2

block Na, K channel

myocyte AP

Question 3

Class II/IV

Answer 3

slow sinus and AV node conduction

pacemaker AP

Question 4

Class I MOA

Answer 4

• some block Na –> prolong QRS
• some block K –> prolong Qt
• use dependence (effective @ fast HR)

Question 5

use dependence

Answer 5

• Class I (IC*)
• bind best in open/inactivated state
• (depress tissue that is freq depolarized –> tachycardia)

Question 6

Class Ia drugs

Answer 6

quinidine
procanimide
disopyramide

Question 7

Class Ia MOA

Answer 7

• block Na (phase 0) (inc QRS)

- some block K (inc QT)

Question 8

Class Ia AE

Answer 8

TDP (prolong QT)

Question 9

quinidine

Answer 9

• Ia
• oral
• dec recurrence rate of afib

AE: inc mortality, Cinchonism

Question 10

procanimide

Answer 10

• Ia
• IV
• slow conduction in accessory path (WPW), arrhythmias (bypass tracts)

AE: drug-induced lupus

Question 11

Class Ib drugs

Answer 11

lidocaine

mexiletine

Question 12

Class Ib MOA

Answer 12

• least effect on AP of CI
• slight dec AP
• RAPID unbind (effective in tachy)
• bind depolarized tissue (ischemia) (B=Best post MI)

AE: CNS stim (tremor, agitation)

Question 13

lidocaine

Answer 13

• Ib

- terminates arrhythmias by turning unidirectional block –> bidirectional block

Question 14

mexiletine

Answer 14

• Ib

- oral version of lidocaine

Question 15

Class Ic drugs

Answer 15

flecainide

propafenone

Question 16

Class Ic MOA

Answer 16

• block open Na, very SLOW unbinding (PROLONGED QRS!!!!!!!!!)
• use in struc NORM heart
• dec afib recurrence

AE: proarrhythmic, cardiac arrest, cox at high HR

Question 17

structurally normal heart

Answer 17

IC

Question 18

use post-MI

Answer 18

IB

B=Best post-MI

Question 19

Class III drugs

Answer 19

amiodarone
ibutilide
dofetilide
sotalol

AIDS

Question 20

Class III MOA

Answer 20

• block K+ –> delay repolarization, prolong QT/AP/ERP in cardiomyocytes
  use: afib, a flutter, vtach

AE: torsades

Question 21

most adverse effects of any of the anti-arrhythmics

Answer 21

amiodarone

Question 22

amiodarone MOA

Answer 22

-CIII, but I/II/IV effects
-blocks K+, Qt
(lowest torsades incidence)

-use: afib, Vtach

-LIPOPHILIC and LONG half life…
AE: liver/lung accumulation, hypER/hypOthyroidism,
inc LFTs, skin sensitivity to sun, blue/gray man, normal deposits, DEATH BY PULMONARY FIBROSIS

Question 23

monitor these labs when rx amiodarone

Answer 23

CXR
PFTs
TFTs
LFTs

Question 24

sotalol

Answer 24

CIII

Question 25

dofetilide

Answer 25

CIII

Question 26

sotalol | dofetilide

Answer 26

- block K+ (inc QT) - REVERSE use-dependence AE: torsades, tox @ slow HR

Question 27

REVERSE use-dependence

Answer 27

- bind best at resting state - tox @ slow HR - CIII

Question 28

Ibutilide

Answer 28

- CIII - IV - use: chemical cardioversion AE: torsades

Question 29

class II antiarrhymics MOA

Answer 29

beta blockers main effects @ pacemaker cells of SA/AV node - dec slope of phase 4 (funny current, Na) --> slows HR - prolong phase 3 (repolariz) --> slows conduction in AV node - -> prolonged PR AE: type I AV block, wenkebach (mobitz I) use: afib, prevent SCD in systolic HF (dec EF pts) --> DEC MORTALITY

Question 30

Class II drugs

Answer 30

``` metoprolol propanolol esmolol atenolol timolol carvedilol ```

Question 31

Class IV drugs

Answer 31

verapamil diltiazem (non-dihydropyridine CCBs)

Question 32

class II AE

Answer 32

AE: type I AV block, wenkebach (mobitz I) - impotence - COPD exacerbation and asthma - CVS effects (bradycardia, AV block, HF) - Mask signs of hypOglycemia

Question 33

Class IV MOA

Answer 33

- block phase 0 of pacemaker AP - slow HR - slow AV conduction use: afib (control ventric. rate) (SVTs) AE: type I AV block, wenkebach (mobitz I)

Question 34

adenosine

Answer 34

"breaks AVNRT" -inc K out (HYPERpolarize) -dec Ca out ^dec AV node conduction - short half life use: dx/terminate certain forms of SVT ``` AE: flushing/hypotension (vasodilator) CP dyspnea doom bronchospasm ```

Question 35

Mg

Answer 35

- blocks Ca influx (avoids early after depolarizations) | use: acute management of torsades AND digoxin toxicity

Question 36

atropine

Answer 36

- muscarinic r. antagonist - parasympathetic block use: bradycardia (*esp via AV block)

Question 37

ivabradine

Answer 37

- selective inhibit of funny Na chan, prolong phase 4, dec SA node firing - negative chronotropic effect w/o isotropy - reduces cardiac O2 req use: chronic stable angina in pt who can't take beta blockers, chronic HF w/ reduced EF AE: luminous phenomena/visual brightness, HTN, bradycardia

Question 38

metoprolol

Answer 38

B1 selective

Question 39

propranolol

Answer 39

B1 and 2 (non-selective)

Question 40

carvedilol

Answer 40

B1 and 2 (non-selective)