Antidysrhythmics Flashcards
1
Q
Steps of Normal Heart Contraction
A
- Ca2+ influx in SA and AV nodes starts AP
- Na+ influx (depolarization) in ventricular muscle cells
- K+ efflux (repolarization) ends AP
2
Q
Describe Heart Contraction
A
AP generation that leads to contraction of the myocardial muscle
3
Q
Arrhythmia
A
“no rhythm”
4
Q
Asystole
A
no heartbeat
5
Q
4 Types of Dysrhythmias
A
- Tachdysrhythmias
- Bradydysrhythmias
- Supraventricular Tachycardia
- Ventricular Tachycardia
6
Q
Tachydysrhythmias
A
- increased HR
- common
7
Q
Bradydysrhythmias
A
- HR is slowed
8
Q
Supraventricular Tachycardia
A
- 120-250 bpm
- AV block desirable
9
Q
Paroxysmal SVT
A
- episodic
- sudden
- returns to normal w/in 24 hrs
10
Q
Persistent SVT
A
- longer than 7 days
- treatment is needed
11
Q
Permanent SVT
A
- lasts more than a year despite treatment
12
Q
Atrial Fibrillation
A
most common
13
Q
Ventricular Tachycardia
A
- ventricular muscle problem (non sustained <30sec or sustained >30sec)
- more dangerous
14
Q
Causes of Dysrhythmias
A
- ischemic heart disease
- myocardial infarction
- cardiomyopathy
- myocarditis
- electrolyte imbalances
15
Q
Symptoms of Dysrhythmias
A
- palpitations dizziness
- fainting
- dyspnea
- *sometimes asymptomatic
16
Q
How do Antidysrhythmics work?
A
- most suppress abnormal electrical impulse formation or conduction
17
Q
Class I MOA
A
- block sodium channels
- stop depolarization
18
Q
Class II MOA
A
- B Blockers
- this stops CA from releasing and decreases cell activity
- block SNS stimulation (AV block)
19
Q
Class II Indications
A
- supra ventricular and ventricular dysrhythmias
20
Q
Class II Example
A
Metoprolol
21
Q
Class III MOA
A
- K channel blockers
- prolongs repolarization and therefore AP
- extends refractory period
22
Q
Class III Example
A
Amioderone- very effective
23
Q
Amioderone Adverse Effects
A
- 75% serious problems
- 10% die
24
Q
Amioderone Indications
A
- ventricular tachycardia or fibrillation, atrial fibrillation, or flutter
- if resistant to other drugs
- sustained ventricular tachycardia
25
Class IV MOA
- CCBs
- reduce cell electrical activity
- inhibits Ca cell entry
- act on AV node- reduce conduction velocity (Av block)
26
Class IV Examples
- Diltiazem
| - Verapamil
27
Class IV Indication
- paroxysmal SVT
- rate control
not for ventricular dysrhythmics
28
Adverse Effect of All Antidysrhythmics
dysrhythmia
29
Digoxin MOA
- AV block
| - slows HR
30
Adenosine MOA
- slows conduction through the AV node (AV block)
| - convert supraventricular tachycardia to sinus rhythm
31
Adenosine Adverse Effects
- may cause asystole for a few seconds
| - dysrhythmias
32
Adenosine 1/2 Life and and Route
- short (10-20 sec)
| - fast IV push
33
Adverse Effects of Dysrhythmics to Watch Out For
- SOB
- Edema
- Dizziness
- Syncope (fainting)
- toxicity
34
Patient Teaching for Antidysrhythmics
- pt to take radial pulse for 1 min (report<60)
35
Therapeutic Responses to Monitor For
- decrease BP
- decrease edema
- regular pulse rate
- pulse rate w/o major irregularities
- improved CO
