Qbank - Anti-Arrhythmics

Front 1

significant QT prolongation following antiarrhythmic med, also notable for mild bradycardia - which med class? Example?

Back 1

QT prolong = ventricular repolarization
mediated by K+ efflux so look for class III (K+ channel blockers)
Sotalol is an example (tho it is a beta blocker, this explains the bradycardia)
others: amiodarone, ibutilide, dofetilide

Front 2

how is lidocaine (class IB) different from other class I anti-arrythmics in terms of AP graph?

Back 2

shortens phase 3 repolarization
has less pronounced effect on phase 0 depolarization (rapid binding, rapid release)

Front 3

name the arrythics for class 1A? Class 1B? Class 1C?

Back 3

class 1A - Disopyramide, Quinidine, Procainamide (Double Quarter Pounder)
class 1B - Lidocain, Tocainide, Mexiletine (Lettuce, Tomato, Mayo)
class 1C - Moricizine, Flecainide, Propafenone (more fries please)

Front 4

characteristics of 1A, B, & C arrythmics on phase 0 & action potential length?

Back 4

1A - intemediate inhibition of phase 0 depol, prolongation of phase 3 repolarization
1B - weak inhibition of phase 0 depol, shortens phase 3 repol
1C - strong inhibition of phase 0 depol, no change to phase 3 repol

Front 5

first & second line tx for atrial fibrillation (w/rapid ventricular response)?

Back 5

1st - calcium channel blockers - diltiazem

2nd - digoxin - slows AV conduction

Front 6

QT prolongation predisposes to?

Back 6

torsades de pointes

Front 7

high QRS voltage in precordial leads indicates?

Back 7

ventricular hypertrophy, should not cause an irregular rhythm

Front 8

QRS interval prolongation indicates?

Back 8

ventricular dyssnchrony or slowed intraventricular impulse conduction

common cause is bundle branch block
heart rate usually regular

Front 9

palpitation post binge-drinking?

Back 9

"holiday heart", episode of atrial fibrillation

Front 10

absent p waves?

Back 10

indicates atrial fibrillation

Front 11

class IB anti arrythmics? Use for?

Back 11

lidocain, mexiletine, tocainide

useful for selectivity for rapidly & frequently depolarizing cells
useful in arrhythmias occuring during ischemic cardiac event (B = best for MI)

shortening action potential & phase 3 repolarization
little effect on rapidity of phase 0 depolarization

Front 12

class IA anti arrythmics? Used for?

Back 12

Qunidine is the major drug

used for tachyarrhythmias in atria & AV junction

have affinity for non-resting sodium channels between 1B (low) & 1C (high)

slow both phase 0 depolarization and phase 3 repolarization