Antidysrhythmic Drugs

Question 1

class I:

Answer 1

sodium channel blockers

Question 2

class II:

Answer 2

beta blockers

Question 3

class III:

Answer 3

potassium channel blockers

Question 4

class IV:

Answer 4

calcium channel blockers (some are better for high bp, some are better for dysrhythmia

Question 5

dysrhythmia definition

Answer 5

an abnormality in the rhythm of the heart

Question 6

two basic types of dysrhythmias

Answer 6

tachydysrhythmia and bradydysrhythmia

Question 7

tachydysrhythmia

Answer 7

heart rate is increased

Question 8

bradydysrhythmia

Answer 8

heart rate is slowed

Question 9

dysrhythmia are also known as

Answer 9

arrhythmias

Question 10

what is the pacemaker of the heart

Answer 10

sinoatrial node - fires 60-100 per min

Question 11

impulse conduction

Answer 11

pathways and timing

Question 12

AV node

Answer 12

fires 40-60 times/min; has pacemaker abilities if SA node fails

Question 13

His- purkinje system

Answer 13

fires less 4o times/min; so used if SA and AV node both shut down

Question 14

cardiac action potentials

Answer 14

occur in fibers of the His-Purkinje system and in atrial and ventricular muscle

Question 15

phases of cardiac action potentials

Answer 15

0 - depolarization; 1 - (partial repolarization; 2 - plateau; 3 - repolarization; 4 - stable potential

Question 16

always have electrical event followed by a **

Answer 16

mechanical effect

Question 17

fundamental causes of dysrhythmias

Answer 17

disturbances of automaticity; disturbances of conduction

Question 18

disturbances of automaticity

Answer 18

SA or AV node will not fire

Question 19

disturbances of conduction

Answer 19

atriventricular block, reentry (recirculating activation) (not conducting through normal pathway of the heart)

Question 20

supravantricular dysrhythmias

Answer 20

impulse arises above the ventricle, atrial flutter, atrial fibrillation, sustain supraventricular tachycardia (SVT)

Question 21

atrial fibrillation

Answer 21

Firing of electrical current in several different places in the atria; clotting prblem with a fib so put pt on anticoagulent; amiodanone diltiazem (cardezan); decreased cardiac output and potential for clots**

Question 22

supraventricular **

Answer 22

any impulse that arrives above ventazole

Question 23

supraventricular tachycardia (SVT)

Answer 23

atria doesn’t dump blood down into ventricles (not as much)

Question 24

ventricular dysrhythmias

Answer 24

sustained ventricular tachycardia; ventricular fibrillation; digoxin-induced ventricular dysrhythmias

Question 25

ventricular dysrhythmias are

Answer 25

life threatening, won't have cardiac output so no pulse ready for death, rapid firing in the ventricles

Question 26

ventricular premature beats

Answer 26

every now and then, too much caffeine or too much stress

Question 27

no pulse and no blood pressure

Answer 27

call 911 and start CPR 1. defiberate; DOC after 2. CPR 3. epinephrine 4. amiodarone 5. potassium or magnesium

Question 28

sodium channel blockers treat

Answer 28

atrial and ventricular dysrhythmias; DOC lidocaine

Question 29

lidociane (xylocaine) effects on the heart and ECG **

Answer 29

blocks cardiac sodium channels - slows conduction in the atria, ventricles and his purkinje system; reduces automaticity in the ventricles and his-purkinje fibers

Question 30

class II:beta blockers - **

Answer 30

propranolol (Inderal), carvedilol (Coreg)

Question 31

carvedilol (Coreg)

Answer 31

specifically for rapid heartbeats

Question 32

class II:beta blockers effects on the heart and ECG **

Answer 32

decreased automaticity of the SA node; decreased velocity of conduction through the AV node; decreased myocardial contractility - negative inotropic effect

Question 33

class II:beta blockers therapeutic effects

Answer 33

dysrhythmias caused by excessive sympathetic stimulation; SA tachydysrhythmias

Question 34

SA tachydysrhythmia

Answer 34

suppression of excessive discharge; slowing of the heart rate

Question 35

class II:beta blockers adverse effects

Answer 35

heart block, heart failure, AV block, sinus arrest, hypotension, bronchospasm (in asthma pts)

Question 36

other class II:beta blockers

Answer 36

acebutolol (sectral), exmolol (brevibloc)

Question 37

class III: potassium channel blockers have both **

Answer 37

atrial and ventricular fibrillation

Question 38

class III: potassium channel blockers

Answer 38

amiodarone

Question 39

class III: potassium channel blockers therapeutic uses

Answer 39

long term therapy for life threatening ventricular dysrhythmias and converting a fib to normal sinus rhythm; recurrent ventricular fibrillation; recurrent hemodynamically unstable ventricular tachycardia

Question 40

amiodarone effects on heart

Answer 40

reduces automaticity in the SA node, reduced contractility, reduced conduction velocity, QRS widening, prolongation of the PR and QT intervals

Question 41

amiodarone adverse effects

Answer 41

1. pulmoary toxicity; cardiotoxicty; toxicity in pregnancy and breast feeding; corneal microdeposits; optic neuropathy (last two high doses)

Question 42

pulmoary toxicity

Answer 42

damage to lung tissue

Question 43

cardiotoxicity

Answer 43

toxic to heart muscle

Question 44

potassium channel blockers have lots of

Answer 44

drug interactions: quidine, diogoxin, procainamide, diliazem, phenytoin, warfarin

Question 45

class IV: calcium channel blockers

Answer 45

verapamil and diltiazem

Question 46

verapamil and diltiazem

Answer 46

reduces SA nodal automaticity; delays AV nodal conduction; reduces myocardial contractility

Question 47

class IV: calcium channel blockers therapeutic uses

Answer 47

slows hr (a fib or atrial flutter); terminate SVT cause by an AV nodal reentrant circuit (slowing of HR and decrease in BP)

Question 48

verapamil and diltiazem adverse effects

Answer 48

bradycardia; hypotension; AV block; heart failure; peripheral edema; constipation

Question 49

adenosine

Answer 49

decreases automaticity in the SA node; slows conduction through the AV node; prolongation of PR interval

Question 50

therapeutic uses of adenosine

Answer 50

termination of paroxysmal SVT

Question 51

paroxysmal

Answer 51

sudden rapid HR

Question 52

adenosine adverse effects

Answer 52

sinus bradycardia, possible assystole; dyspnea; hypotension; facial flushing

Question 53

adenosine drug interactions

Answer 53

methylzanthines, dipyridamole