17- anti-arrhythmic drugs

a. Class I anti-arrhythmic drug

a. Class I anti-arrhythmic drug

1. Quinidine is a

   a. Class I anti-arrhythmic drug

   b. Class II anti-arrhythmic drug

   C. Class III anti-arrhythmic drug

   D. Class IV anti-arrhythmic drug

a. Phenytoin

2. Anti-seizure + Anti-arrhythmia

   a. Phenytoin

   b. Lidocaine

   c. Amiodarone

   d. Quinidine

c. Nifedipine

3. Which of the ff is least useful in arrythmia

   a. Verapamil

   b. Diltiazem

   c. Nifedipine

   d. Esmolol

b. amiodarone

4. Broadest Spectrum anti-arrythmic agent

   a. sotalol

   b. amiodarone

   c. Quinidine

   d. verapamil

d. sotalol

5. Class IB,except

   a. Lidocaine

   b. Mexiletine

   c. Phenytoin

   d. sotalol

SA Node Maker (Pacemaker); 60-100 beats → RV Node (slow action potential) → Bundle of his → bundle branches → Purkinjie Fiber (ventricular contraction)

Heart Conduction System:

S-atrial contraction → PR → Q, R, S (ventricular depolarization → T (ventricular repolarization or recovery state)

Heart Conduction System in ECG:

Phase 4

• Spontaneous Depolarization of pacemaker action potential

• Na influx

Phase 0

• Rapid Depolarization of pacemaker action potential

• Ca+ influx

Phase 3

• Repolarization of pacemaker action potential

• K efflux

Phase 4

• Membrane state; resting state of cardiac muscle cells

• K efflux

Phase 0

• Upstoke; Depolarization of cardiac muscle cells

• Na influx

Phase 1

• Partial Depolarization of cardiac muscle cells

• Rapid opening and closing K channel

Phase 2

• Plaeteau of cardiac muscle cells

• Ca influx = K efflux

Phase 3

• Repolarizing Phase of cardiac muscle cells

• K Efflux

60 to 100 beats per minute

Normal heart beats:

ARRYTHMIA

abnormal heart rhythm disease:

<60 bpm

bradycardia has a heart beat of:

>100bpm

tachycardia has a heart beat of:

ventricle

ventricular arrhythmia is originated in which part of heart?

above ventricle

Supraventricular arrhythmia is originated in which part of heart?

Abnormal automaticity

cell membranes abnormally permeable to sodium generate impulses faster than the SA node

SA node

Pacemaker of the heart

Triggered activity

• abnormal leakage of ions into the cardiac cells

• bump on the action potentials causing after depolarization

Unidirectional block

problem w/ purkinje fiber and SA node in Arrhythmia:

So BaKeCang

• Class I: Sodium Channel Blockers (Largest)

• Class II: Beta-Blockers (can dec HR)

• Class III: Potassium Channel Blockers

• Class IV: Calcium Channel Blocker

ANTI-ARRHYTHMIC DRUGS

Sodium Channel Blockers

Class I anti-arrhythmic drugs:

Beta-Blockers

Class II anti-arrhythmic drugs:

Potassium Channel Blockers

Class III anti-arrhythmic drugs:

Calcium Channel Blockers

Class IV anti-arrhythmic drugs:

suppress ventricular arrhythmia

Class I: Sodium Channel Blockers’ MOA:

Quini is PromDi

• Quinidine

• Procainamide

• Disopyramide

CLASS IA Sodium Channel Blockers:

CLASS IA Sodium Channel Blockers

• MOA: moderate Na Channel Blockers

• Results: Inc action potential, QRS complex, QT interval

Torsaedes de Pointes

CLASS IA Sodium Channel Blockers’ S/E:

diarhhea, thromboctopenia, *cinchonism (tinnitus, blurred vision, dizziness)

Quinidine’s S/E:

SLE-like symptoms

Procainamide’s S/E:

Lid ME TO PH

• Lidocaine

• Mexiletine

• Tocainide

• Phenytoin

CLASS IB Sodium Channel Blockers:

CLASS IB Sodium Channel Blockers

• MOA: mild Na channel blocker

• Results: shorten AP, dec QRS, dec interval

Lidocaine

• Local anesthetic anti-arrhythmia

• parentally

• has a high 1st pass

Mexiletine

• anti-arrhythmia that is an analog of Lidocaine;

• Oral

Phenytoin

A drug that is treatment for seizure & arrhythmia

MOR fun in FL Phines

• Moricizine,

• Flecainide,

• Propafenone

CLASS IC Sodium Channel Blockers:

Esmolol, metoprolol, propranolol

Class II anti-arrhythmic drugs: Beta-Blockers

Class II anti-arrhythmic drugs

• MOA: dec HR, dec AV node, inc refractory period

• Use: prevent and treat supraventricular tachycardia (SVT), as well as ventricular tachycardia

Potassium Channel Blockers

• MOA: block K+ -channels

• Results: Inc AP, QRS, QT

• Use: Tx for Ventricular tachycardia (widely used), atrial fibrillation & flutter

• Amiodarone

• Bretylium, Ibutilide, Sotalol, Dofetilide

Class III: Potassium Channel Blockers:

Amiodarone

• Class III: Potassium Channel Blockers

• Broadest Spectrum

• Ha multi-MOA

hepatotoxicity, pulmonary fibrosis, cardiotoxicity, bluishgrey skin, corneal micro deposits, thyroid abnormalities*, photosensitivity

Amiodarone’s S/E:

Diltiazem and verapamil

Class IV: Calcium Channel Blockers:

Calcium Channel Blockers

• MOA: Dec HR & AV node conduction velocity (little effect), inc AV refractory period (little effect)

• Use: Tx for supraventricular arrhythmia (not effective in ventricular arrhythmia)

• Adenosine

• Digoxin

• Magnesium Sulfate

Miscellaneous anti-arrhythmic drugs:

Adenosine

• Nucleoside = Adenosine + ribose

• extremely short half-life

• Use: PSVT/ acute SVT

Verapamil

Alternative for Adenosine if the px has asthma

Digoxin

• increases vagal tone and thereby slows AV node conduction velocity

• Use: atrial fibrillation (NOT preferred)

Magnesium Sulfate

DOC for TORSADES DE POINTES

metoprolol, verapamil, amiodarone

Tx for Atrial Flutter & Atrial Fibrillation

adenosine, verapamil

Tx for Acute SVT

beta-blockers, CCBs

Tx for Chronic SVT

amiodarone (IV), Lidocaine (IV)

Tx for Acute VT (most common of death)

amiodarone, beta-blockers

Tx for Chronic VT

amiodarone, epinephrine (alternative)

Tx for Ventricular fibrillation (Most dangerous)