Brainscape's Knowledge GenomeTM

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


See full index

pharmacology > Treating Arrythmias > Flashcards

Treating Arrythmias Flashcards

1
Q

Where is the heart beat initiated?

A

In the SA node

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

Via what channels is the resting potential controlled in the SA node?

A

If- funny channels which are cAMP activated. They transport Na+ and K+ across the membrane leading to slowly reach the threshold for depolarisation

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

Which channels cause the upstroke of the slow cardiac action potential?

A

Ca2+ channels.

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

Which channels cause the repolarisation of the slow cardiac action potential?

A

K+ channels

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

How many stages are there in the fast cardiac action potential?

A

5

0,1,2,3,4

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

At which stage do voltage gated sodium channels open in the fast cardiac action potential causing the first upstroke?

A

Stage 0

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

What is the mechanism in the fast cardiac action potential causing the plateau?

A

Transient outflow of potassium ions, influx of Ca2+ into the cell via L type Ca2+ channels which are slow to close.

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

Which pump in the cell membrane is responsible for maintaining the resting potential in the fast cardiac action potential?

A

NaK ATPase.

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

What are the two broad categories of how an arrhythmia may arise?

A

Abnormal impulse generation

Abnormal conduction

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

What types of arrhythmias can cause abnormal impulse generation?

A

Triggered rhythms such as early after depolarisations or delayed after depolarisations.

Ectopic foci
Enhanced normal automaticity = increased frequency of action potentials from SA node.

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

What kinds of arrhythmias can cause abnormal conduction to develop?

A

Re entry mechanisms eg WPW syndrome, circus movement, reflection

Conduction block- 1st, 2nd, 3rd degree

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

What are the different classifications of anti arrhythmic drugs? Briefly describe what each class does.

A

Class Ia- sodium channel blocker
Class IIa- sodium channel blocker
Class Ic- sodium channel blocker, also some K+ and Ca2+ blockade.
Class II- Beta blocker
Class III- K+ channel blocker
Class IV- calcium channel blocker
Digitalis glycosides- positive inotropy, AV nodal blockade
Adenosine- enhances outward flow of K+- hyperpolarisation. Causes sinus bradycardia. Also AV node blocker
Atropine- antimuscarinic- reduces inhibitor effect of vagus nerve on heart.

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

Which drugs are used for treatment of bradycardias?

A

Atropine

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

What can cause sinus bradycardia?

A

MI

Overdose of beta blocker

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

What are the categories of arrythmias?

A

Bradycardias
Supraventricular tachycardia
Nodal tachycardia
Ventricular tachycardia

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

What are the different types of SVTs?

A

Atrial flutter
Atrial tachycardia
Atrial fibrillation
Atrial premature beats.

17
Q

What are the key pathophysiological features of atrial flutter?

A

2:1 conduction ratio to ventricles
Usually arises fro a macro re entrant circuit in right atrium
Atrial rate is 250-250bpm.

18
Q

What characteristic sign is often seen on ECG in patient with atrial flutter?

A

Sawtooth appearance

19
Q

What is the treatment for atrial flutter?

A 
Commonly DC cardioversion.
Pharmacological treatment- class Ic agents are sometimes used but must be given together with an AV nodal blocker to prevent a 1:1 conduction to the ventricles.
20
Q

What is the pathophysiology of atrial tachycardia?

A

Infrequent rhythm disturbance arising from automatic ectopic foci producing an atrial rate of 150-250bpm.

21
Q

What is the pharmacological treatment of atrial ectopic foci?

A

Flecainide to reduce heart rate and restore sinus rhythm+ AV node blocker- beta blocker or CCB

22
Q

What is the pathophysiology of atrial fibrillation?

A

Often occurs without any underlying cause

Often arises from multiple re-entrant circuits in the atria.

23
Q

Why does having atrial fibrillation increase the risk of stroke?

A

The condition predisposes to left atrial thrombus formation and subsequent systemic emboli

24
Q

What are the aims of treatment in atrial fibrillation?

A

Treatment of underlying cause
Restoration of sinus rhythm
Control of rapid ventricular response in persistent or permanent AF

25
Q

What are common underlying causes of AF?

A

Hypertension, valvular heart disease, heart failure, ischaemic heart disease

Chest infections, pulmonary embolism, lung cancer

Systemic causes- excessive alcohol intake, thyrotoxicosis, electrolyte depletion, infections, DM

26
Q

How is sinus rhythm restored in atrial fibrillation?

A 
DC or drug induced cardioversion
Pharmacologically this is done using a single oral dose of flecainide. Sinus rhythm can be maintained with a class Ic drug, sotalol or amiodarone (CCB)
27
Q

How do we control the rapid ventricular response to persistent atrial fibrillation?

A

Digoxin- used to control HR

Av node blocker- CCB or beta blocker

28
Q

What is the first step of treatment in nodal tachycardias?

A

Carotid sinus massage, or sometimes adenosine may be used.

29
Q

How do nodal tachycardias arise?

What is a classic example?

A

Arise from a reentry circuit and are usually initiated by an ectopic beat.

Wolff parkinson white syndrome

30
Q

AV node reentrant tachycardia is another example of a nodal tachycardia. How is it treated?

A

Beta blockers, dilitiazem or verapimil can be used to treat acute episodes.
Junctional tachycardias also respond well to flecainide, sotalol or amiodarone

31
Q

What are the major types of ventricular tachycardias?

A

vetricular fibrillation
Ventricular tachycardia
Ectopic beats

32
Q

When can ventricular ectopic beats occur?

A

In healthy individuals or after an MI

33
Q

What drugs are used to treat ventricular ectopic beats after an MI to reduce the risk of sudden cardiac death?

A

Beta blockers

34
Q

How does ventricular tachycardia present on ECG?

A

Broad QRS complexes

35
Q

What pharmacological treatment is given to non sustained ventricular tachycardia?

A

Beta blockers

36
Q

What pharmacological treatment is given to sustained ventricular tachycardia?

A

Class Ib agents such as lidocaine or amiodarone

pharmacology (22 decks)

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