1. 4-ANTIARRHYTHMIC DRUGS
CARDIAC ARRHYTHMIAS
All arrhythmia Result From
2-Abnormalities of impulse formation
2-Abnormalities of impulse conduction.
3-Both.
Types of arrhythmia :
1. Sinus tachycardia.
2. Sinus bradycardia
3. Extra systoles
4. Atrial flutter
5. Atrial fibrillation
6. Paroxysmal atrial tachycardia
7. Paroxysmal ventricular tachycardia
8. Ventricular fibrillation

2. 9. Heart block
8. Bundle branch block
N.B.
Wolf-Parkinson-White Syndrome (WPW):
accessory atrioventricular pathway which conduct more

3. ANTIARRHYTHMIC DRUGS
 Non-pharmacological treatment are preferred because:
1-Arrhythmogenic effect of the drugs used in treatment of arrhythmias.
2-Efficacy of these methods.
Non Pharmacological techniques
Ablation technique..
Implantable cardiovector defibrillator .
Artificial pacemaker.

4. A-Mechanistic Classifications
CLASS I (SODIUM CHANNEL BLOCKERS)
Ia: Quinidine
Ib: Lidocaine
CLASS II (BETA-BLOCKERS)
CLASS III (POTASSIUM CHANNEL BLOCKERS)
Amiodarone
CLASS IV
 Calcium channel blockers e.g. verapamil, diltiazem( not nifidipine cus it will caus reflex sympathetic stimulation )
Potassium channel openers ( indirect C.C.B) e.g. adenosine

5. B-Therapeutic Classification of Antiarrhythmic Drugs
Supraventricular arrhythmias:
verapamil
digoxin
beta-blockers
Ventricular arrhythmias:
Lidocaine
Supraventicular and ventricular arrhytmias:
Amiodarone
Quinidine

6. CLASS Ia ANTIARRHYTHMICS
QUINIDINE.
Pharmacodynamics
Fast sodium channels blocker
atropine like action
alpha receptor blocking effect

7. Pharmacological Effects
 Effects on the cardiovascular system
 Cardiac effects
-ve inotropic effect.
↓ excitability
↓ automaticity
ENHANCE conductivity in the A-V node ( cus it has atropine like effect) and bundle of His
^ this effect is dangerous can cause paradoxical techacardiya causin death
Effect on blood vessels and BP:
vasodilatation
hypotension with large dose

8. Therapeutic Indications
Atrial fibrillation (of less than 6 months duration).
Patient should be digitalized before quinidine?
to prevent the possible occurrence of "Paradoxical tachycardia".
Atrial flutter
less active than in atrial fibrillation
can be used when digitalis fails.
Paroxysmal atrial tachycardia.
Extrasystoles. Atrial and ventricular.
Ventricular tachycardias.
Maintenance of sinus rhythm
after successful direct current cardioversion.

9. Side Effects and Toxicity
 Idiosyncrasy : abnormal individual response
Cinchonism: حس إن أجراس تدق باذنه وجاي من اسم الشجرة ringing of the ear
Embolism
Paradoxical tachycardia.
Quinidine syncope.
Hypotension: particularly if given intravenously.

10. Precautions before giving QUINIDINE
1st give testing dose 2-digoxin (digitalize the heart) 3-give anti coagulant 4-u shouldn't give QUINIDINE for Old standing atrial fibrillation ( AF) more than 6 months

11. Old standing atrial fibrillation. Congestive heart failure.
Contraindications
Complete A.V block
Old standing atrial fibrillation.
Congestive heart failure.
Hypotension.
Hypersensitivity.
Myasthenia gravis.

12. PROCAINAMIDE
Pharmacological Effects Similar to quinidine It has weak anticholinergic effects. has a ganglion blocking effect. It doesn’t have alpha blocking activity Therapeutic Uses more in Ventricular arrhythmias

13. CLASS Ib ANTIARRHYTHMICS
LIDOCAINE**
the least cardio toxic of antiarrhythmic
Therapeutic Uses
Ideal drug for treatment of ventricular arrhythmias .
*Given IV only
PHENYTOIN (Diphenylhydantoin, DPH)
1-treating epileptic seizures
2-ventricular arrhythmias.
Adverse Effects
Gum hyperplasyia
gingival hyperplasia

14. CLASS III AMIODARONE**لا يخلو امتحان من سؤال عن هذا الدواء
CLASS II BETA-ADRENOCEPTOR BLOCKERS
يستعمل في حالات معينة
Therapeutic Uses : Supraventricular arrhythmias
drug of choice for chest pain and arrhythmias of mitral valve prolapse
CLASS III AMIODARONE**لا يخلو امتحان من سؤال عن هذا الدواء
POTASSIUM CHANNEL BLOCKERS
Broad-spectrum antiarrhythmic drug ( all types of arrhythmia )
Adverse Effects
Corneal microdeposists
disturb thyroid function
photosensitivity
pulmonary fibrosis
myopathy
peripheral neuropathy
hepatotoxicity

15. CLASS IV CALCIUM CHANNEL BLOCKERS
verapamil and diltiazem
Mechanism of Action: delaying conduction in A.V node
OTHER ANTIARRHYTHMICS
DIGOXIN: Delay conduction in A.V node
ADENOSINE
MAGNESIUM SULFATE
ELECTRIC SHOCK THERAPY
 Direct current electric shock will depolarize the heart , then S.A node will work , after that give quinidine

16. CLINICAL APPLICATIONS OF ANTIARRHYTHMIC DRUGS
Atrial Fibrillation
 Emergency Treatment
Digitalis IV is the drug of choice.
Cardioversion
 Non-emergency Treatment
Digitalis is given orally.
Quinidine
Atrial Flutter
Emergency Treatment
I.V. digitalis
 Non-Emergency Treatment
Digitalis is given orally

17. Wolf-Parkinson-White (WPW) Syndrome
Amiodarone ,sotalol
Cardioversion.
Junctional Tachycardias
Vagotonic maneuvers ..( stimulate vagal nerve)
I.V. verapamil
ADENOSINE

18. Ventricular Tachycardia
 Emergency Treatment
Lidocaine ( IV) is the first choice
I.V. amiodarone
Cardioversion
Prophylaxis
I.V. drips quinidine (72 hrs)
Oral quinidine should be continued for at least 3 months especially if there is acute myocardial infarction.

19. Ventricular fibrillation
Torsade de pointes
MAGNESIUM SULFATE
Artificial pacemaker
Ventricular fibrillation
 Lidocaine
procainamide
amiodarone
Bradyarrhythmias and Heart Block
Cardiac pacemaker
Atropine I.V. .
Hydrocortisone I.V. ( if there’s inflammation in conducting tissue)