Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PY365 AF > Treatment of Arrhythmias 1 > Flashcards

Treatment of Arrhythmias 1 Flashcards

1
Q

what is an arrhythmia

A

an abnormality of the hearts rhythm
- one of the most common clinical problems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the presentation of arrhythmias

A
  • asymptomatic
  • palpitations
  • shortness of breath
  • dizziness
  • chest pain
  • syncope
  • stroke
  • sudden death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is used for the diagnosis of arrhythmias

A
  • past medical history
  • risk factors
  • ECG
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how is an ECG taken for diagnosis of arrhythmias

A
  1. record a 12 lead ECG
  2. each lead highlights a particular pattern of the electrical activity of the heart
  3. lead II is commonly used as a rhythm strip
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

where does sinus rhythm originate

A

originates from SA node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do you calculate heart rate

A

Measure R-R interval
Heart rate (bpm)= 30/ number of large squares
or 1500/number of small squares
- if heart rate is irregular= number of R waves in 30 large squares x 10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give examples of Class 1A drugs

A

Procainamide and disopyramide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describe how procainamide/disopyramide are used

A
  1. used in atrial and ventricular arrhythmias
  2. procainamide is unlicensed in UK
  3. disopyramide has anticholinergic side effects
  4. renally excreted
  5. may prolong QT
    rarely used
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Give examples of Class 1B drugs

A

Lignocaine/lidocaine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is lidocaine used for

A

used for suppression of VT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where is lidocaine metabolised

A

liver metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What cautions must be taken with using lidocaine

A
  • more sensitive in hepatic impairment, heart failure and elderly
  • caution in severe renal impairment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why does lidocaine have limited uses

A

It is an IV only drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the main side effects of lidocaine

A

main side effects tend to be neurological and hypotension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the dose of lidocaine

A

lidocaine has a short half life
1. 100mg IV bolus over a few mins, followed by
2. 4mg/min IV infusion for 30 mins
3. 2mg/min for 2 hours
4. 1mg/min and reduce further if continued for over 24 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is an alternative to lidocaine

A

Mexiletine is an oral equivelent
- unlicensed in UK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the main side effects of mexiletine

A

nausea and vomiting- take with or after food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Give examples of Class 1C drugs

A

Flecanide and propafenone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is flecanide and propafenone used for

A

indicated for atrial and ventricular arrhythmias
- propafenone only used under specialist supervision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the difference between flecanide and procainamide

A

flecanide is a fluorinated analogue of procainamide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what cautions must be taken with the use of flecanide and propafenone

A
  • not for use in heart failure or any coronary heart disease
  • use with caution as often causes other arrhythmias
22
Q

when are beta blockers indicated

A

indicated in atrial and ventricular arrhythmias
- reduce affects if sympathetic system on automaticity and conductivity

23
Q

What cautions should be taken when using beta blockers

A
  • can be co-prescribed with digoxin but not with verapamil and care with diltiazem
  • contraindicated in asthma
  • caution in COPD, PVD and diabetes
24
Q

Which beta blocker has class III action

A

sotalol

25
Q

which beta blocker can be used in hospital for SVT

A

Esmolol (IV)

26
Q

Explain why sotalol has both class 2 and class 3 action

A

sotalol is a racemic mixture of D and L isomers
- D sotalol is pure class III (antiarrhythmic)
- L sotalol has class III and beta blocker activity

27
Q

What doses of sotalol should be given to achieve class II or III effects

A
  • low dose (80mg OD) achieves beta blocker effects
  • doses greater than 160mg/day achieve class III effects
28
Q

What could sotalol cause

A

May prolong QT interval

29
Q

What cautions must be taken in use of sotalol

A
  • avoid in hypokalaemia
30
Q

When is sotalol used

A

Used for SVT including AF and atrial flutter

31
Q

Describe the pharmacology of how amiodarone works

A
  1. blocks sodium channels (class 1 action)
  2. inhibits sympathetic stimulation (class II action)
  3. blocks potassium channels ( class III action)
  4. blocks calcium channels (Class IV action)
  5. lengthens the action potential duration and increases the refractory period, slowing heart rate
  6. improve electrical homogeneity (convert to SR)
32
Q

what is the solubility of amiodarone

A

highly lipophilic

33
Q

What is the dose of amiodarone

A
  1. loading dose required due to long half life (30-100 days)
  2. licensed oral loading dose:
    - 200mg tds for 7 days then
    - 200mg bd for 7 days then
    - 200mg OD thereafter
  3. IV central vein with ECG monitoring
34
Q

Outline the adverse effects of amiodarone

A
  1. cardiac- worsen arrhythmia, new arrhythmia, QT prolongation, new or worsening heart failure
  2. skin- photosensitivity
  3. optic- corneal micro deposits, optic neuropathy
  4. thyroid- hypo/hyperthyroidism
  5. hepatic- baseline LFTs for all new patients
  6. pulmonary- pulmonary fibrosis
  7. neurological- tremor, peripheral neuropathy
  8. GI- nausea, vomiting, anorexia
35
Q

what is dronedarone used for

A

used for non permanent atrial fibrillation
- for maintenance of SR post DCCV not controlled by other drug therapy

36
Q

What needs to be monitored in use of dronedarone

A
  • measure creatinine 7 days after initiation
  • monitor liver function
37
Q

what are the cautions with the use of dronedarone

A
  • not for heart failure patients
  • increased risk of mortality
  • may prolong QT interval
38
Q

What is the dose of dronedarone

A

400mg bd
- reduce digoxin dose by 50%

39
Q

What are the similarities between amiodarone and dronedarone

A
  1. both require extensive monitoring
  2. all 4 classes of action
  3. converts to SR
  4. drug interactions
40
Q

What are the differences between amiodarone and dronedarone

A
  1. amiodarone contains iodine, dronedarone does not
  2. amiodarone has a long half life, dronedarone has a short half life
  3. amiodarone accumulates in tissues, dronedarone has reduced accumulation in tissues
  4. amiodarone is licensed for use in heart failure, dronedarone is not
  5. amiodarone is licensed for arrhythmias including AF, SVT, VT and VF, dronedarone is only for non permanent arrhythmias
  6. amiodarone is oral and IV administration, dronedarone is oral dosing only
41
Q

Give an example of a dihydropyradine calcium channel blocker

A

nifedipine

42
Q

What are the main effects of dihydropyradine calcium channel blockers

A

mainly peripherally acting drugs
- they are vasodilators
- very effective in reducing high blood pressure and in angina but have very little effect on heart rate

43
Q

What are the main effects of diltiazem and verapamil

A

have antiarrhythmic properties by reducing conduction through AV node and reducing heart rate

44
Q

What is the mechanism of action of digoxin

A

inhibits Na/K ATPases and increases intracellular calcium concentration by inhibiting Na/Ca exchange
- has positive inotropic effect (increases force of myocardial contraction)
- has negative chronotropic effect (reduces heart rate)

45
Q

What should be monitored with use of digoxin

A

K+ levels- ensure K+ in range to avoid digoxin toxicity

46
Q

How is digoxin excreted

A

Excreted by kidneys

47
Q

What could digoxin cause

A

May cause ST and T wave changes

48
Q

When is the peak concentration of digoxin

A

6 hours after oral dose

49
Q

What are the indications of digoxin

A

AF, atrial flutter

50
Q

How does adenosine work

A

Blocks conduction at AV node and can be used to terminate SVT

51
Q

What is the half life of adenosine and when do its effects occur

A

Has a very short half life of 0.5-5 seconds
- on administration, effects occur after 20 seconds

52
Q

What are the main side effects of adenosine

A

flushing, chest pain, metallic taste

PY365 AF (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions