Cardiac Arrhythmia Drugs

Question 1

Name the types of cardaic arrhythmic drugs

Answer 1

Class IA, IB, IC - Na channel blockers

Class II - beta blockers

Class III - K channel blockers

Class IV - CCB

Adenosine

Vernakalant

Atropine

Digoxin

Ivabradine

Question 2

Name some class IA antiarrhythmics and how they are given

Answer 2

Procainamide

Quinidine

Disopyramide

Given IV or PO

Question 3

What cardiac effects do class IA antiarrhythmics have and how does this look on an ECG

Answer 3

Decreased conduction by decreasing phase 1/Na entery

Increased refractory by increased the AP duration and increasing Na channel inactivation

Decreased automacitiy by decreasing the slope of phase 4

Increased threshold

ECG: increased QRS, increased QT

Question 4

What are class IA antihypertensives used for

Answer 4

Quinidine - maintain sinus rhythm in AF and atrial flutter, and prevents recurrence.

Procainamide - acute IV treatment of supraventricular and ventricular arrhythmias

Question 5

What are the side effects of class IA antiarrhythmics

Answer 5

Hypotension

Decreased CO

Proarrhythmic

Insomnia

Seizure

GI effects

Lupus-like syndrome

Question 6

Name some class IB antiarrhythmics and how they are given

Answer 6

Lidocaine - IV

Question 7

What cardiac effects do class IB arrhythmics have and how does this appear on an ECG

Answer 7

Decreased AP duration

Decreased phase 0 conduction in fast beating/ischaemic tissue

Increased threshold

ECG: increased QRS in fast/ischaemic tissue

Question 8

Name some uses of class IB arrhythmics

Answer 8

Acute - ventricular tachycarida

Not used in atrial arrhythmias or AV junctional arrhythmias

Question 9

Name some side effects of class IB arrhythmics

Answer 9

Proarrhythmic - less than class IA

Dizziness

Drowsiness

Abdominal upset

Question 10

Name some class IC antiarrhythmics and how they are given

Answer 10

Flecainide

Given PO or IV

Question 11

What cardiac effects do class IC antiarrhythmics have and how does this appear on an ECG

Answer 11

Decreased phase 0

Increased threshold

Increased AP duration

Increased refractory period

ECG: increased PR, increased QRS, increased QT

Question 12

Name some uses of class IC antiarrhythmics

Answer 12

Supraventricular arrhythmias

Premature ventricular contractions

Wolff-Parkinson-White syndrome

Question 13

Name some side effects with the use of class IC antiarrhythmics

Answer 13

Proarrhythmic

Risk of sudden death

CNS and GI effects like other local anaesthetics

Increased ventricular response to supraventricular arrhythmias - flecainide flutter

Question 14

Name some class II antiarrhythmics and how they are given

Answer 14

Propranolol - PO/IV

Bi​soprolol - PO

Question 15

Describe the cardiac effects of class II antiarrhythmics and how they affect the ECG

Answer 15

Increased refractory period - prolong plateau

Decrease phase 4 depolarisation

Increased AP duration and refractory period in AV node to slow conduction

ECG: increased PR, decreased HR

Question 16

Name some uses of class II antiarrhythmics

Answer 16

Sinus and catecholamine depenedent tachycardia

Converting re-entrant arrhythmias at AV node

Protect ventricles from high atrial rate

Used following MI

Question 17

Name some side effects from the use of class II antiarrhythmics

Answer 17

Bronchospasm

Hypotension

Question 18

Name some class III antiarrhythmics and how they are given

Answer 18

Amiodarone - PO/IV

Sotalol - PO

Question 19

Describe the cardiac effects of amiodarone and how this appears on an ECG

Answer 19

Increased refractory period

Increased AP duration

Increased threshold

Decreased phase 0 and conduction

Decreased phase 4

Decreased speed of AV conduction

ECG: decreased HR, increased PR, increased QRS, increased QT

Question 20

Name some uses for amiodarone and name some side effects of its use

Answer 20

Effective for most arrhythmias

Serious side effects that increase with time, e.g. pulmonary fibrosis, hepatic injury, increased LDL, thyroid disease, photosensitivity, optic neuritis

Question 21

Describe the cardiac effects of sotalol and how they appear on an ECG

Answer 21

Increased AP duration

Slow phase 4

Slow AV conduction

ECG: increased QT, decreased HR

Question 22

Name some uses and side effects of sotalol

Answer 22

Uses: supraventricular and ventricular tachycardia

Side effects: proarrhythmic, fatigue, insomnia

Question 23

Name some class IV antiarrhythmics and how they are given

Answer 23

Verapamil - PO/IV

Diltiazem - PO

Question 24

Describe the cardiac effects of class IV antiarrhythmics and how they appear on an ECG

Answer 24

Slow conduction through the AV node

Increased refractory period in AV node - increased plateau phase of AP

Increased slope of phase 4 in SA node to slow HR

ECG: increased PR, increased or decreased HR

Question 25

Name some uses and side effects of class IV antiarrhythmics

Answer 25

Uses: SVT, convert SVT

Caution when parital AV block as get asystole is beta-blocker also used

Caution when hypotensive, decreased CO or sick sinus syndrome

Side effect: GI upset