Anti-Arryhtmics Flashcards
Phase of the Cardiac Action Potential where Na+ and Ca2+ are rushing in.
Phase 0 (Depolarization)
Phase of the Cardiac Action Potential where Na+ channels close.
Phase 1
Phase of the Cardiac Action Potential where Ca2+ continues to go into the cell and K+ is leaving the cell.
Phase 2
Phase of the Cardiac Action Potential where K+ leaves the cell and Ca2+ channels close.
Phase 3 (Rapid Repolarization)
Phase of the Cardiac Action Potential with leaky K+ channels.
Phase 4 (Resting Potential)
What Class of medications works on Phase 0 of the Cardiac Cycle?
Class 1 = Na⁺ Channel Blocker
What Class of medications works on Phase 4 of the Cardiac Cycle?
Class 2 = Beta Blocker
What Class of medications works on Phase 3 of the Cardiac Cycle?
Class 3 = K+ Channel Blocker
What Class of medications works on Phase 2 of the Cardiac Cycle?
Class 4 = Ca²⁺ Channel Blocker
What does the Relative Refractory period coincide with on an EKG?
T Wave Apex
Ia Na⁺ Channel Blockers
Disopyramide
Quinidine
Procainamide
Ib Na⁺ Channel Blockers
Lidocaine
Mexiletine
Ic Na⁺ Channel Blockers
Flecainide
Propafenone
Beta Blockers
Metoprolol
Atenolol
K⁺ Channel Blockers
Amiodarone
Fofetilide
Ibutilide
Sotalol
Non-Dihydropyridine Ca²⁺ Channel Blockers
Diltiazem
Verapamil
Class V Medications
Adenosine
Digoxin
Medications that slow the rate of rise of phase 0 by prolonging the duration of action potential and increases the effective refractory period of the ventricle.
Class Ia Na⁺ Channel Blockers
(↑ ERP + ↑ AP Duration)
What do Class Ia Na⁺ Channel Blockers treat?
Ventricular + Atrial Arrhythmias in patients without a history of ischemic heart disease
What is an adverse drug reaction caused by Class Ia Na⁺ Channel Blockers?
Lupus-Like Syndrome
Increase Arrhythmias
Medications that shorten the action potential duration and refractory period of the Purkinje Fibers and ventricular muscles.
Class Ib Na⁺ Channel Blockers
(↓ ERP + ↓AP Duration)
When do you give Class Ib Na⁺ Channel Blockers?
Ventricular Arryhtmias
What is a Class Ib Na+ Channel Blocker that is 2nd line in treating V-Tach and V-Fib?
Lidocaine
Is Lidocaine effective against Atrial Arrhythmias?
No
Medication that has the greatest effect on early depolarization. Can cause a markedly prolonged QRS during normal sinus rhythm.
Class Ic Na⁺ Channel Blockers.
What is the indication for a Class Ic Na⁺ Channel Blocker?
Supra-ventricular Arrhythmias in patients without structural heart disease.
Medications that block cardiac Beta-1 receptor and reduces cAMP
Beta Blockers
- Metoprolol
- Propranolol
- Atenolol
- Esmolol
What do Beta Blockers ultimately result in?
Cardiac Membrane Stabilization
Slowed SA + AV Node Conduction
↑ Refractory Period
What are Beta-Blockers used to treat?
Re-infarction & sudden death in patients with HF or MI.
What are some adverse drug reactions caused by Beta-Blockers?
AV BLOCK
Bronchospasm
Cardiac Depression
Hypotension
Medications that prolong or delay repolarization.
K⁺ Channel Blockers
What do all K⁺ Channel Blockers do?
Prolong QT
(Amiodarone does it the least)
What is the drug of choice for the acute treatment of V-Tach and V-Fib?
Amiodarone
What medications are safe to treat heart failure with A-Fib?
Amiodarone
Dofetilide
What are two adverse drug reactions of K⁺ channel blockers?
QT Prolongation
Torsades de Pointes
What are some signs of Amiodarone toxicity?
GI = Nausea + Vomiting
Pulmonary = Pulmonary Fibrosis
Endocrine = Hyper or Hypo Thyroid
Eyes = Corneal Microdepsoits (100%)
Liver = Heptatotoxicity
What is the half-life of Amiodarone?
52 days
(Reactions can take Months or Years)
How does Amiodarone interact with Warfarin?
Inhibits Warfarin Metabolism
↑ INR
Tx: ↓ Warfarin by 50%
How does Amiodarone interact with Digoxin?
↑ Digoxin Effect
↑ Risk of AV Block
↑ Risk of GI + Neuro Toxicity
Tx: ↓ Digoxin by 50%
How does Amiodarone interact with Statins (HMG Co-A Reductase Inhibitors)
Inhibits Statin Metabolism
↑ Risk of Myopathy + Myalgia
Tx: Avoid high doses of:
Lovastatin
Atorvastatin
Simvastatin
Medications that slow conduction through the AV node and increase the effective refractory period in the AV node.
Ca²⁺ Channel Blockers
Ca²⁺ channel blockers prolong what?
PR Interval
What is an indication for a Ca²⁺ channel blocker?
A-Fib rate control
What are some adverse drug reactions of Ca²⁺ channel blockers?
Cardiac:
- Negative Inotrope
- AV Node Block
- Sinus Arrest
Non-Cardiac:
- Peripheral Vasodilation
- Constipation
Class of medications used for Ventricular Arrhythmias and A-Fib.
Ia + Ic Na⁺ Channel Blockers
Class of medications used for A-Fib, Ventricular Arrhythmias, and Post-Myocardial Infarction.
Beta Blockers
Class of medications used for Atrial and Ventricular Arrhythmias, especially when other drugs fail.
K⁺ Channel Blockers
Class of medications effective for A-Fib and A-Flutter.
Ca²⁺ Channel Blockers
Medication that can cause tinnitus, headache, vision changes, thrombocytopenia, and lupus-like syndrome.
Quinidine
Medication that can cause CNS effects, confusion, and seizures.
Lidocaine
Medication that is pro-arrhythmic, especially in structural heart disease.
Flecainide
Medications that can cause Bradycardia, Hypotension, and Bronchospasm.
Beta-Blockers
Medications that can cause QT Prolongation.
K⁺ Channel Blockers
Medication that can cause pulmonary fibrosis, thyroid abnormalities, and hepatotoxicity.
Amiodarone
Medication that can cause AV Blocks, bradycardia, and hypotension.
Ca²⁺ Channel Blockers
Medication used to treat paroxysmal SVT.
Adenosine
What are some adverse drug reactions of Adenosine?
Flushing
Dyspnea
AV Block
Arrhythmia
Medication that partially inhibits Na⁺/K⁺ ATPase Pump and increases contraction without effecting heart rate.
Digoxin
When is Digoxin used?
2nd or 3rd Line for: A-Fib or Heart Failure
What are some adverse drug reactions caused by Digoxin?
Nausea + Vomiting
Blurred Vision + Halos
AV Block
MUST MONITOR DRUG LEVEL
What medications can cause QT Prolongation?
Class 1A and III
Tricyclic Antidepressants
Quinolones
Phenothiazines
Haloperidol
Zofran
