Arrhythmia - therapy Flashcards
What is an arrhythmia?
Any deviation from the normal rhythm of the heart
What are the different types of arrhythmias?
Sinus arrhythmia
Supraventricular arrhythmia
What causes supraventricular arrhythmia?
Atrial fibrillation
SVT
What causes ventricular arrhythmia?
Ventricular tachycardia
Ventricular fibrillation
What are class IA, IB and IC drugs?
Fast, intermediate and slow sodium channel blockers
Give examples of class IA drugs
Quinidine
Procainamide
Dispyramide
Give examples of class IB drugs
Lidocaine
Mexiletine
Tocainide
Give examples of class IC drugs
Flecainide
Propafenone
Give examples of class II drugs
Atenolol
Bisoprolol
Give examples of class III drugs
Amiodarone
Bretylium
Sotalol
Give examples of class IV drugs
Diltiazem
Verapamil
What are class II drugs?
Beta blockers
What are class III drugs?
Prolong refractoriness by reducing or blocking sympathetic nervous system stimulation
What are class IV drugs?
Calcium channel blockers
What is the first line of medication for Atrial fibrillation?
Class II drugs such as atenolol or bisoprolol
Name the antidysrythmics that don’t fit into one class
Digoxin
Adenosine
How does Digoxin work?
Inhibits the sodium-potassium ATPase pump so has a positive inotropic effect, improving strength of cardiac contraction
What has to be monitored when using Digoxin?
Potassium levels
Drug interactions
What are the signs of Digoxin toxicity?
Nausea Vomiting Xanthopsia Bradycardia Tachycardia Arrhythmia - VT and VF
What is the treatment for Digoxin toxicity?
Stop Digoxin
Give Digibind if levels of Digoxin are very high
When is Digoxin toxicity most serious?
When Potassium levels are low
How does adenosine work?
Slows conduction through the AV node so turns paroxysmal supraventricular tachycardia to sinus rhythm
How should adenosine be administered?
Fast IV push
What can adenosine cause for a few seconds?
Asystole
What can all antiarrhythmics cause?
Arrhythmias
Name some anticoagulants
Warfarin Dabigatran Rivaroxaban Apixaban Edoxaban
What are anticoagulants used for?
Valvular heart disease Atrial fibrillation Thromboembolism Deep vein thrombosis risk After surgery
When is atrial fibrillation most common?
After the age of 60
How does Warfarin work?
Inhibits production of active clotting factors
What drugs promote warfarin activity?
Aspirin Sulfonamides Cimetidine Disulfiram Oral antibiotics Heparin antimetabolites
What drugs decrease warfarin activity?
Barbiturates
Phenytoin
Vitamin K
Cholestyramine
What are the adverse effects of warfarin?
Bleeding
Teratogenic
When should the use of warfarin be avoided in pregnancy?
First and third trimesters
What should be done when monitoring warfarin therapy?
Regular INR
Patient education
Alcohol intake
Watch if altered therapy
How is the risk of bleeding assessed with warfarin?
CHADS2 score Congestive heart failure Hypertension Age >75 years Diabetes Mellitus Stroke or TIA
What are class I drugs?
Membrane-stabalizing agents
What are class II drugs used for?
General myocardial depressants for both supra ventricular and ventricular dysrhythmias
What are class III drugs used for?
Used for difficult dysrhythmias such as:
Life threatening ventricular tachycardia or fibrillation
Atrial fibrillation or flutter
Sustained ventricular tachycardia
What are class IV drugs used for?
Paroxysmal supra ventricular tachycardia
Rate control for atrial fibrillation and flutter
What is Amiodarone used for?
Ventricular tachycardia
Supra ventricular tachycardia
What are the side effects of amiodarone?
Thyroid problems Pulmonary fibrosis Slate Corneal deposits LFT abnormalities
