Arrhythmias Flashcards
rate and rhythm of the heartbeat is set by the rapidly firing cells in the?
sinoatrial node
NSR originates in the?
SA node
what causes the atrium to contract
SA node
what causes the ventricles to contract
purkinje fibers
define supraventricular arrhythmia
originating above the AV node
define ventricular arrhythmia
originating below the AV node
define ventricular tachycardia
series of PVCs in a row resulting in a heart rate >100
also absence of peripheral pulse
which antiarrhythmics prolong the QT interval
Class 1-especially 1a class 3
common drugs that prolong QT interval (7)
quinolones macrolides azoles TCAs SSRIs 5-HT3 receptor antagnoists antipsychotics
when is a QTc considered prolonged
> 440 msec
How to remeber vaughan williams drug classes
Double Quarter Pounder, Lettuce, Mayo, Fries Please!
Because Dieting During Stress Is Always Very Difficult
Class 1a Vaughan williams
Disopyramide
Quinidine
Procainamide
Class 1b Vaughan Williams
Lidocaine
Mexiletine
Class 1c Vaughan Williams
Flecainide
Propafenone
Class 2 Vaughan Williams
Beta-blockers
Class 3 Vaughan Williams
Dronedarone Dofetilide Sotalol Ibutilide Amiodarone
Class 4 Vaughan Williams
Verapamil
Diltiazem
Rate control for Afib
Beta blockers
Non-DHP
digoxin
Rhythm control for Afib
Class 1a, 1c, or 3 antiarrhythmics
Goal HR in symptomatic Afib
< 80
Goal HR in asymptomatic Afib
<110
Afib with HFrEF should not recieve
non-DHP
Define paroxysmal Afib
terminates spontaneously or within 7 days of onset
Define persistant afib
sustained > 7 days
Define long-standing persistent afib
continuous > 12 months
Define permanent afib
joint decision has been made to cease further attempts to restore or maintain NSR
Define valvular afib
moderate to severe mitral stenosis or with a mechanical heart valve; long-term anticoagulation with warfarin is indicated
Define non-valvular afib
without moderate to severe mitral stenosis or a mechanical heart valve
Cardioversion and thromboembolism prophylaxis
started 3 weeks prior
continued for at least 4 weeks
MOA of class 1 VW class
Na-channel blocker
MOA of class 2 VW class
beta-blocker
MOA of class 3 VW class
K-channel blocker
MOA of class 4 VW class
CCB-non-DHP
MOA of digoxin
Na-K-ATPase blocker
MOA of adenosine
activates adenosine receptors to decrease AV node conduction
What is the preferred antiarrhythmic used in HF
amiodarone
What is the indication for adenosine
paroxysmal supraentricular tachyarrthmias (PSVTs)
warning for amiodarone (6)
pulmonary toxicity hepatoxicity proarrhythmic hyper/hypothyroidism (hypo more common) optic neuropathy photosensitivity
contraindication for amiodarone
iodine hypersensitivity
Amiodarone and digoxin dosing
decrease digoxin by 50%
Amiodarone and warfarin dosing
decrease warfarin by 30-50%
Amiodarone and simvastatin and lovastatin dosing
simvastatin max 20 mg/day
lovastatin max 40 mg/day
therapeutic range of digoxin with Afib
0.8-2 ng/mL
which electrolytes levels can cause increased risk of digoxin toxicity
low K, Mg
High Ca
Major SE for disopyramide
Anticholinergic effects
Warning for quinidine
hemolysis risk (avoid in G6PD deficiency) Drug-induced lupus erthematosus
Boxed warning for procainamide
agranulocytosis
drug-induced lupus erhtematosus
Class 1b is used in what only
ventricular arrhythmias
no efficacy in afib
Dronedarone boxed warning
increased risk of death, stroke, HF in pateints with decompensated HF or permanent Afib