AV BLOCKS

Question 1

What is the defining characteristic of first degree AV block?

Answer 1

Delayed introduction of electrical impulse

Question 2

Where does the delay occur in first degree AV block?

Answer 2

AV node

Question 3

What is the normal PR interval range?

Answer 3

0.12-0.20sec

Question 4

What causes first degree AV block?

Answer 4

• degenerative changes (age)
• medications: BBs, CCBs, Digoxin, antiarrhythmics
• MI, Ischemia, Myocarditis

Question 5

When do we treat a patient who has first degree AV block?

Answer 5

If they are symptomatic

Question 6

What is the defining characteristic of second degree type 1 AV block?

Answer 6

Prolonged lengthening of or interval until QRS complex drops

Question 7

What can you call second degree type 1 AV block?

Answer 7

Wenckebach or Mobitz I

Question 8

Is the ventricular rhythm regular or irregular?

Answer 8

Irregular

Question 9

What does the drop beat indicate?

Answer 9

No ventricular contraction

Question 10

What are causes of second degree type 1 AV block?

Answer 10

• CAD
• Meds
• inferior wall MI
• rheumatic fever

Question 11

What are a few symptoms for a patient with second degree type 1?

Answer 11

• rapid heart rate
• palpitations
• decreased CO

Question 12

Where does Mobitz II occur?

Answer 12

Occasional failure of impulse conduction below the AV node

Question 13

In Mobitz II, what are the regularity ones of the atrial and ventricular rhythms?

Answer 13

The atrial rhythm is regular and the ventricular is irregular

Question 14

In Mobitz II, what is the atrial and ventricular rate?

Answer 14

Atrial is 60 bpm
Ventricular is 50 bpm

Question 15

What causes Mobitz II?

Answer 15

• anterior wall MI
• degenerative changes
• severe CAD

Question 16

What are some symptoms of second degree type 2 AV block?

Answer 16

• decreased CO: dyspnea, fatigue, dizzy
• hypotension
• bradycardia

Question 17

How do we treat second degree type 2 av block?

Answer 17

• ECG monitoring
• Oxygen
• transcutaneous or temporary pacemaker
• IV push meds for bradycardia (Atropine)

Question 18

What is third degree av block known as?

Answer 18

Complete heart block

Question 19

What is a characteristic of third degree av block?

Answer 19

Complete absence of impulse between atria and ventricles

Question 20

When 3AVB is at the junctional escape level what are the characteristics?

Answer 20

Transient- short lived
Favorable prognosis

Question 21

When 3AVB is at the infranodal level what are the characteristics?

Answer 21

• unstable pacemaker
• ventricular asystole
• bad prognosis
• life threatening

Question 22

In 3AVB is the rhythm regular or irregular?

Answer 22

Regular

Question 23

What is the rate for atria and ventricles in 3AVB?

Answer 23

Atria 90bpm
Ventricles 30bpm

Question 24

T/F: there are more p waves than QRS complexes in 3 AVB.

Answer 24

True

Question 25

What causes 3AVB?

Answer 25

- av node damage - inferior wall MI - drug toxicity - at infranodal: anterior wall Mi

Question 26

What to look for if a patient has 3AVB?

Answer 26

- changed LOC - CP - diaphoresis - pallor - slow peripheral pulse

Question 27

How do we treat 3AVB?

Answer 27

- oxygen - strict bed rest - pacemaker - no atropine