Anti-Arrythmic agents Flashcards
What ECG changes do you see in WPW?
Shortened PR
Lengthened QRS
Which class 1 agent is only used for ventricular arrhythmia?
Lidocaine
What are the side effects of 1a agents?
Pro-arrythmia
Hypotension
Dizziness, confusion
GI
What ECG changes does flecainide cause?
Increase QRS, QT and PR (also decreases automaticity)
What ECG changes do 1a agents cause?
Increase QRS and QT
What ECG changes do 1b agents cause?
Increase QRS in ischaemic tissue only
What are the side effects of flecainide?
Pro-arrythmia
Sudden death with chronic use
CNS
GI
What effects do beta blockers have?
Decrease phase 4 - automaticity
Prolong AV repolarisation - increased RP
What effects do beta blockers have on ECG?
Decrease HR
Increase PR
What arrhythmia are beta-blockers used to treat?
Converting re-entry at AV node
SVT - protect ventricles from high atrial rates
Sinus tachycardia
Why are beta-blockers used post-MI?
Decrease oxygen demand of heart - negative isotropy and chronotropy
Inhibit sympathetic activity following MI - ventricular arrhythmias.
What are the side effects of beta blockers?
Bronchospasm - asthmatic Hypotension Tremor Fatigue Insomnia Cold hands
When are beta blockers inappropriate?
Partial AV block or heart failure - decrease CO
What are the side effects of Amiodarone?
Pulmonary fibrosis Raised LDL Hypothyroidism Optic neuritis Hepatic injury Photosensitivity
What effect does Sotalol have on ECG?
Lengthened QT
Decreased HR
What are side effects of sotalol?
Pro-arrythmia
Fatigue
Insomnia
What type of CCB are used to treat arrhythmias?
Phenylalkylamine - verapamil
What are the effects of CCB?
Decrease automaticity - Phase 0 pacemaker
Decrease AV conduction
Increase AV refectory period
What ECG changes with CCB?
Increased PR
HR altered - baroreflex
What are SE of CCB?
Hypotension
GI
What is the mechanism of adenosine?
Endogenous - given IV, short t1/2
A1 receptors - Gi coupled - opens K+ channels -> hyperpolarisation
What are the effects of adenosine?
Slows AV conduction
Decrease automaticity - phase 4
What is adenosine used for?
CAD diagnosis
Re-entrant supra ventricular arrhythmias
What is vernakalent mechanism?
Atrial specific K+ channel blocker.
Decrease atrial conduction
Potency increases as HR increases
What is vernakalent used for?
Convert recent onset AF to sinus rhythm
What is Ivabradine MOA?
Inhibits If in SA node - decrease automaticity and HR.
What is a SE of Ivabradine?
Flashing lights
What is Ivabradine used for?
Sinus tachycardia
Decrease HR in HF or angina as NO effect on BP
What is digoxin MOA?
Increase vagal activity, RP
Decrease AV conduction and slow HR
Inhibit Na+/K+ ATPase - increase inotropy
What is digoxin used for?
Not used alone
Slow HR in permanent AF patients
How does atropine work?
Muscarinic antagonist - block vagal activity
What is atropine used for?
Vagal bradycardia - increase AV conduction and HR
What AF rate control drugs are there?
Beta blocker -bisprolol
CCB - verapamil, diltiazem
+/- Digoxin
What AF rhythm control drugs are there?
Sotalol
Flecainide + bisoprolol
Amiodarone
When must flecainide never be used?
If structural abnormality or IHD
Alone to treat AF - need AV node blocking drug, either BB or CCB.
What is used to treat ventricular tachycardia?
Beta blocker
Lidocaine - if ischaemia
Amiodarone
What is used to treat WPW?
Flecainide
Amiodarone
