Anti-arrythmics Flashcards
Risk/benefits
generally arrythmias effect quality of life, but are not lethal. Many theraputics have the potential to be
What is the only anti-arrythmic that has been shown to improve quality of life?
beta blocker
Mechanisms of arrthymia
Re-entry, automatcity, triggered activity
How Effective is anti-arrythmic therapy?
50%-60% effective
Proarrythmia
changing the rythm induces a different type of arrythmia
fleticanide side effect
25% expereince vertigo
atrial fibrilation-treatment
doesnt have as strong a success rate with ablation. therefore generally use a medical approach.
Dofetilide and sotalol
potasium blocking. prolong repolarization, can significantly prolong QTc and can cause V arrythmia
flutocinide contraindications
can cause proarrythmia in the presence of structural heart abnormality, such as post MI
ICD
preferred method for individuals in the high risk category, or for those with significant Vtac Varrythmias.
Class IA anti-arrythmics
moderate sodium and potassium channel blocker. Quinidine, procainiamide, dysopyramide
Class 1B antiarrythmic
weak Na channel blocker. Lidocaine, Mexillitiene. Vtac only
Class 1C antiarrythmics
Strong Na channel blockers. Flecainide, Propafenone
Sotalol
class III antiarythmic, beta blocker. Prolongs PR and QT interval, can lead to proarythmia like everything else
Cardiac contraindication Class I?
structural heart disease, ie post MI, should not use sodium channel blocker as has a higher chance of becoming proarrythmic.
Dofetilide
Class III antiarythmic, K+ channel blocker
K+ channel blockers lead to highest risk of what dangerous arrythmia?
Torsade de pointe
Amiodarone
Class I,II,III,Iv activity, though typically clasified as class 3. does lots of different things. Can be toxic in the liver, used also in pulmonary fibrosis, must check lung function tests when used. Basically if something odd goes wrong and patient is on this drug, could be the culprit
Dronedarone
Class III antiarythmic. blocks K+ channels, counterindicated in heart failure.
Ibutilide
pseudo class III antiarrythmic. increases repolarizing Na current, effectivly prolonging the refractory phase (hence the pseudo class III)
Adenosine
pseudo class IV. Stimulates iK channel and inhibits iCa channel in SA and AV node cells, slowing conduction. For SVT only.
Class IV antiarrythmics
verapamil, diltiazame, Nicardapine. prevents slow influx of calcium so prevents phase 0.
What is the prefered method to control arrythmia?
structural, ICD.
