Arrhythmics Flashcards

1
Q

Pathway of a heartbeat

A
  1. SA node
  2. R/L atria - atria contract
  3. AV node
  4. Bundle of His > ventricles
  5. right bundle branch
  6. left bundle branch
    purkinje fibers
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2
Q

Arrthymia is caused

A

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

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3
Q

Phase 0

A

rapid ventricular depolarization
-influx of Na = ventricular contraction (represented by the QRS)

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4
Q

Phase 1

A

early rapid repolarization
-Na channels close

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5
Q

Phase 2

A

influx of Ca and efflux of K

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6
Q

Phase 3

A

rapid ventricular repolarization
efflux of K = ventricular relaxation (T wave)

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7
Q

Phase 4

A

resting membrane potential is established
atrial depolarization occurs (represented by P wave)

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8
Q

QT prolonging drugs: antiarrhythmics

A

class Ia, Ic, III

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9
Q

QT prolonging drugs: anti-infectives

A

antimalarials, azole antifungals (all except Cresemba), macrolides, quinolones, lefamulin

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10
Q

QT prolonging drugs: antidepressants

A

SSRIs (escitalopram and citalopram), TCAs, mirtazapine, trazodone, venlafaxine

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11
Q

QT prolonging drugs: antimetics

A

5-HT3 receptor antagonists, droperidol, metoclopramide, promethazine

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12
Q

QT prolonging drugs: antipsychotics

A

1st gen (haldol, chlorpromazine, thioridazine)
second gen (ziprasidone)

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13
Q

QT prolonging drugs: oncology medications

A

ADT (leuprolide)
TKI (nilotinib)
Oxaliplatin

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14
Q

QT prolonging drugs: other

A

cilostazol, donepezil, fingolimod, hydroxyzine, loperamide, methadone, ranolazine, solifenacin, tacrolimus

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15
Q

Class I

A

Disopyramide, Quinidine, Procainamide
-pro-arrhythmic

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16
Q

Class Ib

A

Lidocaine, Mexiletine
-pro-arrhythmic

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17
Q

Class Ic

A

flecainide, propafenone
-pro-arrhythmic

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18
Q

Class II

A

BB
-slow ventricular rate in AF

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19
Q

Class III

A

dronedarone, dofetilide, sotalol, ibutilide, amiodarone

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20
Q

Class IV

A

Verapamil, diltiazem

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21
Q

Way to remember classes of antiarrthymics

A

Double Quarter Pounder
Lettuce Mayo
Fries Please!
Because
Dieting During Stress is always
Very Difficult

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22
Q

Class I: Na channel blockers

A

proarrhythmic

23
Q

Class II: BB

A

slow ventricular rate in AF

24
Q

Class III: K channel blockers

A

-amiodarone and dronedarone block K channels, Ca channels, Na channels, and alpha- and beta-adrenergic receptors
-amiodarone and dofetilide are used for AF in patients with HF

25
Q

Class IV: Ca-channel blockers, non-DHP

A

slow ventricular rate - DO NOT USE IN PATIENTS WITH HFREF

26
Q

Digoxin

A

Na-K-ATPase blocjer
-decrease HR by enhancing vagal tone and positive iontropy

27
Q

Adenosine

A

activates adenosine receptors to decrease AV node conduction
-used for paroxysmal SVT

28
Q

Valvular AF

A

AF with moderate to severe mitral stenosis or with mechanical heart valve; long-term anticoagulation with warfarin is indicated

29
Q

Non-valvular

A

AF without moderate to severe mitral stenosis or mechanical heart valve `

30
Q

Goal resting HR in those with symptomatic AF

A

<80 BPM

31
Q

Goal for resting HR for those with asymptomatic AF

A

< 110 BPM

32
Q

Rate control

A

BB or Non-DHP CCBs (sometimes digoxin in patients with refractory or those who cannot tolerate first line agents)

33
Q

Rhythm control

A

-restore and maintaine NSR
-Class Ia, Ic, or III drug or cardioconversion (must be anti-coagulated before cardioconversion)
-if AF is permanent, avoid rhythm-control strategy

34
Q

Stroke ppx

A

-NOACs are preferred over warfarin for stroke prevention in non-valvular AF
-warfarin is indicated for stroke prevention in patients with AF and a mechanical heart valve

35
Q

Amiodarone safety

A

-pulmonary toxicity
-hepatotoxicity
-iodine hypersensitivity
-Hyper/hypo thyroidism
-optic neuropathy
-photosensitivity (slate blue skin discoloration)
-peripheral neuropathy

36
Q

Amiodarone induced thyroid disorder

A

inhibits peripheral conversion of T4 to T3

37
Q

Amiodarone infusion

A

infusions > 2 hours require a non-PVC container (polyolefin or glass); PVC tubing is okay
-use 0.22 micron filter, central line preferable
-incompatible with heparin (flush line with saline); many Y-site additive incompatibilities

38
Q

Amiodarone and digoxin

A

decrease digoxin dose by 50%

39
Q

Amiodarone and Warfarin

A

decrease dose by 30-50%

40
Q

Amiodarone and simvastatin and lovastatin

A

20 mg TDD of simvastatin and 40 mg TDD of lovastatin

41
Q

amiodarone and sofosbuvir

A

increases the bradycardiac effect of amiodarone - do not use together

42
Q

Digoxin range for AF

A

0.8-2 ng/mL

43
Q

when to draw digoxin levels

A

12-24 hrs after dose

44
Q

digoxin antidote

A

Digifab

45
Q

What disorders increase the risk of digoxin toxicity

A

Hypokalemia, hypomagnesemia, and hypercalcemia

46
Q

disopyramide

A

anticholinergic (myasthenia gravis)

47
Q

Quinidine

A

take with food or milk
-hemolysis (G6PD deficiency)
-DILE
-Cinchonism - tinnitus, hearing loss, blurred vision, headache, delirium

48
Q

Procainamide

A

-injection
-active metabolite NAPA and is renally cleared
-therapeutic level: 4-10 mcg/mL
-boxed warning: agranulocytosis, antinuclear antibody (ANA) that leads to DILE
-acetylation leading to drug accumulation and toxicity

49
Q

Lidocaine

A

-injection
-refractory VT/cardiac arrest

50
Q

Flecainide

A

do not use in HF or MI

51
Q

Propafenone

A

do not use in HF or MI
-metallic taste

52
Q

Dronedarone (Multaq)

A

-increased risk of death, stroke and HF in patients with decompensated HF or permanent AF
-Do not use strong CYP3A4 inhibitors and QT prolonging drugs
-hepatic failure, pulmonary disease,
-does not contain iodine and has little effect on thyroid

53
Q

Sotalol (Betapace AF, Betapace, Sotylize Sorine)

A

-CrCl < 60 mL change the frequency and adjust dosing to CrCl