Drugs for cardiac arrhythmias 1

Question 1

List the sinus rythms and values

Answer 1

Sinus rhythms
* Sinus bradycardia <60
* Sinus tachycardia >100

Question 2

List the atrial rythm

Answer 2

Atrial rhythms
(Supraventricular tachycardia SVT)
* Atrial flutter
* Atrial fibrillation
* AV nodal re-entrant tachycardia

Question 3

List the ventricular rhythms

Answer 3

Ventricular rhythms
* Ventricular tachycardia (V-tach)
* Ventricular fibrillation (V-fib)

Question 4

What is the disadvantage for drug therapy for arrhythmias

Answer 4

• Drug therapy for serious arrhythmias is unsatisfactory and dangerous

Question 5

Antiarrhythmic may do what?

Answer 5

Antiarrhythmic may suppress arrhythmias successfully, but paradoxically increase mortality.

Question 6

Pharmacological therapy, particulary chronic therapy should be instituted only for what?

Answer 6

Pharmacological therapy, particularly chronic therapy should be instituted only for haemodynamically important sustained arrhythmias, after a search for correction of any simple precipitating factors and consideration of alternative treatment (e.g. catheter ablation, implantable cardioverter / defibrillator).

Question 7

Only uses whihc classes in consultation with an arrhythmia expert

Answer 7

Only use Class I and III agents in consultation with an arrhythmia expert.

Question 8

List drug classes for antiarrhythmic drugs

Answer 8

• Class I: drugs that block voltagesensitive sodium channels. They are subdivided: Ia, Ib and Ic
• Class II: β-adrenoceptor antagonists
• Class III: drugs that substantially prolong the cardiac action potential
• Class IV: calcium antagonists

Question 9

List the drugs name for class la of antiarrhythmics

Answer 9

Disopyramide,
quinidine,
procainamide

Question 10

Mechanisms for antirrhthymics class la

Answer 10

Sodium channel block (intermediate dissociation) – prolong action potential duration

Question 11

Drug name for class lb of antirrhythmics

Answer 11

Lidocaine

Question 12

Mechanisms of Lidocaine

Answer 12

Sodium channel block (fast dissociation) – shorten action potential duration

Question 13

List drug name for class lc of antirrhythmics

Answer 13

Flecainide

Question 14

MoA of flecainide

Answer 14

Sodium channel block (slow dissociation) – do not affect action potential duration

Question 15

List drugs for class II in antiarrhythmics

Answer 15

Propranolol
Esmolol
Metopralol

Question 16

MoA for class II of antiarrhythmics

Answer 16

Beta blockers

Question 17

List drugs for class III in antiarrhythmics

Answer 17

Amiodarone, Sotalol

Question 18

MoA of class III for antiarrhythmics

Answer 18

Potassium channel block - prolong duration of cardiac action potential

Question 19

List drugs for class IV in antiarrhythmics

Answer 19

Verapamil, diltiazem

Question 20

MoA of class IV in antiarrhythmics

Answer 20

Calcium channel block – block slow inward calcium channel of SA and AV nodes