Answers 100 Verified answers

IBHRE CEPS

Answers (100% Verified answers)

Class 1 Anti-Arrhythmic Mechanism - Answer Sodium (Na) Channel Blockers

Class II Anti-Arrhythmic Mechanism - Answer Beta Blockers

Class III Anti-Arrhythmic Mechanism - Answer Potassium (K) Channel Blockers

Class IV Anti-Arrhythmic Mechanism - Answer L-Type Calcium (Ca) Channel Blocker

Class Ia drugs - Answer -Quinidine (rarely used) -Procainamide -Disopyramide.

Na Channel blockers that raise APD

Class Ib drugs - Answer -Lidocaine -Mexiletine -Phenytoin

Na Channel blockers that slightly lower APD

Class Ic drugs - Answer -Propafenone -Flecainide

Na Channel blockers that don't change APD

Class II Drugs - Answer -Propranolol -Atenolol -Esmolol -Metoprolol

Beta-Blockers. (β-blockers) 1 / 2

Class III Drugs - Answer -Amiodarone -Dronedarone -Sotalol -Ibutilide -Bretylium

Prolong APD (K Channel Blocker)

Class IV Drugs - Answer -Verapamil -Diltiazem

L-Type Ca Channel Blockers

Phase 0 AP - Answer -Depolarization -Rapid Na+ Channels are stimulated to open, flooding the cell with positive sodium ions.-Depolarizatoin of one cell triggers the Na+ channels in surrounding cells to open causing wave of propogation.

Phase 1 AP - Answer -Initial Stage of Repolarization -Inactivation of the fast Na+ Channels

Phase 2 AP - Answer -Plateau Phase -Sustained by a balance between inward movement of Ca2+ through L-type calcium channels (opened in response to depolarization) and outward movement of K+ through the slow K+ channel.-Reduced potassium ion permeability

Phase 3 AP - Answer -Rapid Repolarization Phase -Ca2+ channels close -Slow K+ remains open -Ionic pumps restore ion concentrations back to balanced states of pre-AP

Phase 4 AP - Answer -Resting Membrane Potential

Alpha Adrenergic Receptor site effect - Answer Vasoconstriction

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