Antidysrhythmics

Question 1

Steps of Normal Heart Contraction

Answer 1

1. Ca2+ influx in SA and AV nodes starts AP
2. Na+ influx (depolarization) in ventricular muscle cells
3. K+ efflux (repolarization) ends AP

Question 2

Describe Heart Contraction

Answer 2

AP generation that leads to contraction of the myocardial muscle

Question 3

Arrhythmia

Answer 3

“no rhythm”

Question 4

Asystole

Answer 4

no heartbeat

Question 5

4 Types of Dysrhythmias

Answer 5

1. Tachdysrhythmias
2. Bradydysrhythmias
3. Supraventricular Tachycardia
4. Ventricular Tachycardia

Question 6

Tachydysrhythmias

Answer 6

• increased HR

- common

Question 7

Bradydysrhythmias

Answer 7

• HR is slowed

Question 8

Supraventricular Tachycardia

Answer 8

• 120-250 bpm

- AV block desirable

Question 9

Paroxysmal SVT

Answer 9

• episodic
• sudden
• returns to normal w/in 24 hrs

Question 10

Persistent SVT

Answer 10

• longer than 7 days

- treatment is needed

Question 11

Permanent SVT

Answer 11

• lasts more than a year despite treatment

Question 12

Atrial Fibrillation

Answer 12

most common

Question 13

Ventricular Tachycardia

Answer 13

• ventricular muscle problem (non sustained <30sec or sustained >30sec)
• more dangerous

Question 14

Causes of Dysrhythmias

Answer 14

• ischemic heart disease
• myocardial infarction
• cardiomyopathy
• myocarditis
• electrolyte imbalances

Question 15

Symptoms of Dysrhythmias

Answer 15

• palpitations dizziness
• fainting
• dyspnea
• *sometimes asymptomatic

Question 16

How do Antidysrhythmics work?

Answer 16

• most suppress abnormal electrical impulse formation or conduction

Question 17

Class I MOA

Answer 17

• block sodium channels

- stop depolarization

Question 18

Class II MOA

Answer 18

• B Blockers
• this stops CA from releasing and decreases cell activity
• block SNS stimulation (AV block)

Question 19

Class II Indications

Answer 19

• supra ventricular and ventricular dysrhythmias

Question 20

Class II Example

Answer 20

Metoprolol

Question 21

Class III MOA

Answer 21

• K channel blockers
• prolongs repolarization and therefore AP
• extends refractory period

Question 22

Class III Example

Answer 22

Amioderone- very effective

Question 23

Amioderone Adverse Effects

Answer 23

• 75% serious problems

- 10% die

Question 24

Amioderone Indications

Answer 24

• ventricular tachycardia or fibrillation, atrial fibrillation, or flutter
• if resistant to other drugs
• sustained ventricular tachycardia

Question 25

Class IV MOA

Answer 25

• CCBs
• reduce cell electrical activity
• inhibits Ca cell entry
• act on AV node- reduce conduction velocity (Av block)

Question 26

Class IV Examples

Answer 26

• Diltiazem

- Verapamil

Question 27

Class IV Indication

Answer 27

• paroxysmal SVT
• rate control
  not for ventricular dysrhythmics

Question 28

Adverse Effect of All Antidysrhythmics

Answer 28

dysrhythmia

Question 29

Digoxin MOA

Answer 29

• AV block

- slows HR

Question 30

Adenosine MOA

Answer 30

• slows conduction through the AV node (AV block)

- convert supraventricular tachycardia to sinus rhythm

Question 31

Adenosine Adverse Effects

Answer 31

• may cause asystole for a few seconds

- dysrhythmias

Question 32

Adenosine 1/2 Life and and Route

Answer 32

• short (10-20 sec)

- fast IV push

Question 33

Adverse Effects of Dysrhythmics to Watch Out For

Answer 33

• SOB
• Edema
• Dizziness
• Syncope (fainting)
• toxicity

Question 34

Patient Teaching for Antidysrhythmics

Answer 34

• pt to take radial pulse for 1 min (report<60)

Question 35

Therapeutic Responses to Monitor For

Answer 35

• decrease BP
• decrease edema
• regular pulse rate
• pulse rate w/o major irregularities
• improved CO