Brainscape's Knowledge GenomeTM

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


See full index

Cardio > Arrhythmias > Flashcards

Arrhythmias Flashcards

1
Q

How are arryhthmias named?

A

From the chamber were they originate and from the mechanism

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

what does the term supraventricular mean

A

the origin of the arrhythmia is above the ventricle, atria or AV node

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

What does the term ventricular mean?

A

The origin of the arrhythmia is in the ventricle (ventricular muscle or fascicles)

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

What is a ectopic beat?

A

a beat which originates outside of the conduction pathway and competes with the normal beat

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

What causes an ectopic beat to take over from sinus rhythm as the main beat?

A

If the ectopic beat is faster than the sinus rhythm

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

What is the most common mechanism of arrhythmia?

A

Re-entry arrhythmias

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

What are the symptoms of arrhythmias?

A 
Palpitations, ”pounding heart”
Shortness of breath
Dizziness
Loss of consciousness; ”Syncope”
Faintness: “presyncope”
Sudden cardiac death
Angina, heart failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what happens in defibrillation?

A

electrical current is delivered across the heart straight away

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens in direct current cardioversion (DCCV)?

A

The electrical current waits until the QRS complex to shock the patient

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

If there is patient is stable and has VT what do you do?

A

anaesthetise them to then deliver DCCV

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

What is one of the benefits of ICDs over defibrillation or DCCV?

A

that it is not painful

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

what is the most common arrhytmia?

A

Atrial Fibrillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a cardiac arrhythmia?

A

disturbances of heart rate, or rhythm (regularity of beats) – can be caused by changes in impulse formation, or impulse conduction

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

How are arrhythmias clinically described?

A 
In terms of rate 
- bradycardias (HR < 60 bpm in the day < 50 bpm at night) tachycardias (HR > 100 bpm)
in terms of site of origin 
supraventricular (atria &amp; AV node)
ventricular
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is involved in alterations in impulse formation?

A
  • changes in automaticity

- triggered activity

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

What causes abnormalities in impulse conduction to arise?

A

re-entry
conduction block
accessory tracts

17
Q

How are pacemaker potentials in the heart fired in each node?

A

Each node possesses automaticity and will fire a action potential if not being suppressed
The SA node (70-80 bpm) usually dominates over the latent pacemakers such as the AV node (50-60 bpm) and the Purkinje fibres (30-40 bpm) due to override suppression
For the SA node to be in control it needs to discharge action potentials at a regular frequency greater than any other structure in the heart

18
Q

What drugs might cause DADs?

A

those which increase Ca2+ influx or Ca2+ release from the sarcoplasmic reticulum e.g. catecholamines or digoxin

19
Q

What ensures that the SA node’s pacemaking it relied upon over the other latent pacemakers within the heart?

A

It has the highest rate and is dominant over the other latent pacemakes such as the AV node and Purkinje fibres (30-40 bpm)
- it must discharge action potentials at a regular frequency greater than any other structure within the heart

20
Q

What can happen if the SA node firing is pathologically low?

A

there can be an escape beat initiated by a latent pacemaker - potentially give rise to an escape rhythm

21
Q

What can happen id a latent pacemaker fires at an intrinsic rate faster than the SA node?

A

an ectopic beat or ectopic rhythm

can be a result of ischaemia, hypokalaemia, increased sympathetic activity, fibre stretch and other causes

22
Q

In what way can there be loss of overdrive suppression from the AV node in response to tissue damage (MI)?

A

even the non-pacemaker cells when partially depolarised may assume spontaneous activity

23
Q

What is an afterpolarisation?

A

an abnormal oscillation in action potential - if the amplitude is sufficient to reach threshold it can cause premature APs and beats

24
Q

What is an early afterpolarisation EAD?

A

occurs during the inciting AP either in phase 2 - mediated by Ca2+ channels when Na+ channels are still inactivated or in phase 3 - mediated by Na+ channels (when partial recovery of Na+ channels from inactivation has occurred)

25
Q

What are the risk factors of EADs?

A
  • HR is slow
  • occur in Purkinje fibres
  • associated with prolongation of the AP and drugs prolonging the QT interval
  • can lead to torsades de pointes if sustained
26
Q

What is an delayed afterpolarisations (DADs)

A
  • occur after complete repolarisation
  • caused by a large increase in Ca2+
  • excessive [Ca2+]i results in
    oscillatory release of Ca2+ from the sarcoplasmic reticulum (SR)
    a transient inward current (Iti, involving Na+-influx) that occurs in phase 4
27
Q

What are the risk factors of DADs?

A
  • when HR is fast
  • increased in incidence by prolongation of the AP by drugs
  • decreased in incidence by prolongation of the AP by drugs
  • triggered by drugs that increase Ca2+ influx (e.g. catecholamines), or release, from the SR (e.g. digoxin)
28
Q

What is re-entry?

A

When there is a unidirectional block anterograde conduction is prohibited and retrograde conduction is allowed

29
Q

What are the different types of heart block?

A

1st degree - long PR interval
2nd degree - Mobitz type 1 & mobitz type 2
3rd degree - complete heart block

30
Q

What is mobitz type 1?

A

PR interval gradually increases from cycle to cycle until AV node fails completely and a ventricular beat is missed

31
Q

what is mobitz type 2?

A

PR interval is constant but every nth. ventricular depolarization is missing

32
Q

What is the significance of conduction pathways parallel to the AV node?

A

A common example is the bundle of Kent
impulse through bundle of Kent is conducted more quickly than that through the AV node
ventricles receive impulses from both the normal and accessory pathways – can set up the condition for a re-entrant loop predisposing to tachyarrhythmias

33
Q

What drugs would be used for treatment of atria arrhymias?

A

Classes 1C and III

34
Q

What drugs would be used for treatment of ventricle arrhymias?

A

Classes 1A, 1B, II

35
Q

What drugs would be used for treatment of AV node arrhymias?

A

Adenosine
digoxin
classes II, IV

36
Q

What drugs would be used for treatment of atria and ventricles accessory pathways arrhymias?

A

amiodarone
sotalol
classes 1A, 1C

Cardio (36 decks)

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