Arrhythmias

Question 1

quinidine

Answer 1

Ia
For A-fib, a-flutter, PSVT, ventricular arrhythmias
ECG: may increase sinus rate, QT, and QRS
AEs: N/V/D (30%); TdP (first 72 hours)
DIs: warfarin, digoxin

Question 2

disopyramide

Answer 2

Ia
For paroxysmal supraventricular tachycardia (PSVT)
ECG: may increase sinus rate, QT, and QRS
CI: glaucoma
AEs: anticholinergic effects; TdP; ADHF
Renal dosing

Question 3

mexiletine

Answer 3

Ib
For ventricular arrhythmias
ECG: may decrease sinus rate
CI: 3rd degree AV HB
AEs: CNS

Question 4

propafenone

Answer 4

Ic
For a-fib, a-flut, PSVT, ventricular arrhythmias
ECG: may decrease sinus rate; increase PR & QRS
CIs: HF class II-IV, liver dx, valvular dx (TdP), CAD, VT
AEs: metallic taste, dizziness
DIs: may increase digoxin & warfarin levels

Question 5

flecainide

Answer 5

Ic
For a-fib, a-flut, PSVT, ventricular arrhythmias
ECG: may decrease sinus rate; increase PR & QRS
CIs: HF, CAD, valvular/LV hypertrophy (TdP)
AEs: dizziness, tremor, VT
DI: increase digoxin levels; flecainide levels may be increased by haloperidol, cimetidine, & fluoxetine

Question 6

B-Blockers (i.e. metoprolol)

Answer 6

II
For a-fib, a-flut, PSVT, ventricular arrhythmias
ECG: decrease sinus rate

Question 7

amiodarone

Answer 7

III
For SV & ventricular tachycardias
ECG: decrease sinus rate; increase PR, QRS & QT
CIs: iodine hypersensitivity; hyperthyroid; 3rd degree AV HB
AEs: pulmonary fibrosis; thyroid dysfunction; heparotoxicity; neurologic tox; TdP; AV block; photosensitivity; visual disturbances; sinus brady
DIs: decrease warfarin & digoxin dose by 25-50%; simvastatin max dose = 20mg

Question 8

dronedarone

Answer 8

III
For Paroxysmal or persistent a-fib & a-flut
ECG: decreased sinus rate; increased PR

Question 9

sotalol

Answer 9

III
For ventricular arrhythmias, maintenance of a-fib & a-flut
ECG: decreased sinus rate; may increase PR, QT
Renal elimination & dosing
CIs: baseline QTc > 0.45 sec or CrCl < 40 in atrial arrhythmias
AEs: HF exacerbation, bradycardia, AV heart block, bronchospasm, TdP 3-8% w/in 3 days (start in hospital)

Question 10

dofetilide

Answer 10

III
For supraventricular arrhythmias; a-flut and a-fib conversion
ECG: increase QT
Renal & hepatic elimination
CIs: baseline QTc > 0.44 sec or CrCl < 20
AEs: TdP, dizziness, diarrhea
DIs: CYP 3A4 inhibs; ketoconazole, verapamil, trimethoprim, megestrol, d/c HCTZ
*need 3 month washout after amiodarone
**REMS: initiate in hospital, renally dose, ECG monitor

Question 11

diltiazem & verapamil

Answer 11

IV
For a-fib, a-flut, PSVT
ECG: decreased sinus rate

Question 12

digoxin

Answer 12

For a-fib

ECG: decreased sinus rate

Question 13

Class Ia

Answer 13

Na channel blockers

quinidine, disopyramide

Question 14

Class Ib

Answer 14

Na channel blockers

mexiletine

Question 15

Class Ic

Answer 15

Na channel blockers
propafenone, flecainide
Avoid w/HF or post-MI

Question 16

Class II

Answer 16

beta blockers

metoprolol

Question 17

Class III

Answer 17

K channel blockers

amiodarone, sotalol, dofetilide

Question 18

atrial tachycardia

Answer 18

first line: nondihydropyridine calcium channel blockers; B-Blocker (assess pulmonary status)
second line: combo of class Ia or class Ic w/ an atrioventricular nodal-blocking agent; class III agent

Question 19

atrial fibrillation rate control

Answer 19

B-blockers (mortality benefit in post-MI and LV dys)
non DHP CCB (avoid in LV dys)
digoxin (consider in pts w/HF, not usually monotherapy)
amiodarone (when not responding to AV node blockers)
AV node ablation

Question 20

a-fib rhythm control cardioversion

Answer 20

flecainide, propafenone;

sotalol (does not convert but prevents recurrence), amiodarone (most effective), dofetilide, dronedarone

Question 21

postoperative a-fib

Answer 21

prevention: B-Blockers, sotalol, amiodarone
Rate control: AV blocking agents
recurrent or refractory: antiarrhythmic agents
*also need antithrombotics when it occurs

Question 22

a-flutter

Answer 22

AV node blocking agents (more difficult to control rate)
Class Ia and Ic drugs
Class III drugs

Question 23

AV node re-entrant tachycardia

Answer 23

long-term pharmacologic managment:
standard: nonDHP CCBs; B-blockers; digoxin
nonresponsive without structural heart dx: Class Ic (flecainide and propafenone) (pill in the pocket)
nonresponsive with structural heart dx: class III, class Ia

Question 24

premature ventricular contractions (PVCs)

Answer 24

no drug therapy necessary unless systolic HF & frequent PVCs then B-blockers or amiodarone if neccessary

Question 25

sustained VT

Answer 25

ICD

if needed: ablation, sotalol, B-blocker plus amiodarone, amiodarone