Brainscape's Knowledge GenomeTM

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


See full index

ECG > AV Blocks > Flashcards

AV Blocks Flashcards

1
Q

What are the characteristics of 1st degree AV block?

A 
Regular rhythm
P waves present
PR interval is abnormally long
PR ratio = 1:1
QRS commonly narrow or may be wide in case of pre-existing BBB
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the cause of 1st degree AV block?

A

Inferior MI involving the AV nodal branch of the right coronary artery and hyperactivity of parasympathetic pathways

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

What is the treatment for 1st degree AV block?

A

Doesn’t normally require pacing

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

What will 40% pt of pts with 1st degree AV block develop?

A

Higher AV node block

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

What is frequency filtering?

A

Atrial repolarisation more rapid than AV node repolarisation causing atrial flutter

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

What causes a PR ratio of >1:1?

A

Frequency filtering

Diseased AV conduction (2nd degree AV block)

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

What are the characteristics of 2nd degree type 1 AV block?

A

Rhythm = atrial regular, ventricular irregular
P waves present
PR interval = increase in PR interval with dropping of P wave (sequence repeats)
PR ratio = 3:2, 4:3, 5:4 etc
QRS normal

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

What are the causes of 2nd degree type 1 AV block?

A

AV node disease or damage following ischeamia or inflammation
Increased vagal tone following inferior MI, drug toxicity, digoxin, propranolol and verapamil

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

What is the treatment for 2nd degree type 1 AV block?

A

Atropine if pt becomes symptomatic

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

What are the characteristics of 2nd degree type 2 AV block?

A

Rate = sinus
Rhythm = atrial regular, ventricular irregular
P waves present
PR interval is constant when present, normal duration
PR ratio = 3:2, 4:3, 5:4 or more
QRS normally wide

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

What are the causes of 2nd degree type 2 AV block?

A

Extensive anterio-septal MI

Conduction defect at the BB level, resulting in a wide, bizarre QRS

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

What is the treatment for 2nd degree type 2 AV block?

A

It doesn’t respond to atropine

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

What are AV blocks characterised by?

A

Irregularities in PR interval and PR ratios

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

What are the characteristics of 2nd degree advanced AV block?

A

Similar to 2nd degree type 2 in respect to PR interval duration
Atrial beat drop is more extensive
Conduction ratio = 2:1, 3:1 up to 5:1

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

What is the treatment for advanced 2nd degree AV block?

A

Pacing

Atropine enhances rate

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

What are the characteristics or 3rd degree heart block?

A

Rhythm = regular
Pacemaker sites = SA node or other ectopic atrial sites
P waves have no relationship with QRS complex
PR interval = irregular
QRS may be narrow or wide

17
Q

What is the cause of 3rd degree AV block?

A

Destruction of bundle of His or both bundle branches

ECG (19 decks)

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