Chapter 8 PowerPoint

Question 1

Normal conduction: ____ Node sends signal to ____ node?

Answer 1

SA Node sends signal to AV node

Question 2

Two types of heart blocks?

Answer 2

Partial
Complete

Question 3

Types of partial heart blocks?

Answer 3

Partial – first degree, second degree, type 1, type 2

Question 4

What is a complete heart block?

Answer 4

Complete – third degree

Question 5

What are heart blocks known as?

Answer 5

Known as conduction disturbances
Signal to AV node and bundle of His is interrupted

Question 6

How does a first degree AV block appear on a ECG?

Answer 6

Prolonged PR interval, consistent beat to beat
>.20 sec with each cardiac cycle
1 p wave for every QRS complex
HR normal, Bradycardia or tachycardia
Normal P wave shape unless Atrial Enlargement

Question 7

5 causes of a first degree AV block?

Answer 7

-Enhanced Parasympathetic tone
-AV nodal disease
-Coronary Artery disease
-Medications
-Electrolyte disturbances

Question 8

Treatment for fist degree AV block?

Answer 8

Benign, No treatment progression but monitor
Bradycardia?? Atropine to elevate HR

Question 9

What is second degree AV block also called?

Answer 9

Mobitz 1 or Wenckebah phenomenon or Mobitz II

Question 10

What are characteristics and how does a Mobitz 1 AV appear on an ECG?

Answer 10

1 dropped beat, P wave nonconductive
PR interval progressively increase until p wave appears w/o QRS complex
Generally, 3-5 beats run of progressing PR intervals precede non-conducted beat
Repeats the same pattern

Question 11

Causes of Mobitz 1?

Answer 11

Medication
Ischemia RCA
Enhanced Vagal Tone
Amyloidosis and sarcoidosis
Acute inferior wall myocardial infarction

Question 12

Treatment for Mobitz 1?

Answer 12

Benign rhythm, no tx necessary
Watch for progressing block
Atropine if symptomatic bradycardia

Question 13

Where does Mobitz II occur?

Answer 13

Mobitz II or Type II Occurs below the AV node with high percentage distal to the bundle of HIS

Question 14

Heart rate possibilities associated with Mobitz II?

Answer 14

Irregular ventricular rate or regular bradycardic ventricular rate

Question 15

Mobitz type II is often ____ or ____?

Answer 15

Often undiagnosed or misdiagnosed

Question 16

Severity of Mobitz II?

Answer 16

Can be life threatening

Question 17

How does Mobitz II appear on an ECG?

Answer 17

Intermittent nonconductive p waves without progressive prolongation of PR intervals
Dropped QRS complex, irregular R-R intervals
Regular non-conducted P waves, regular R-R interval

Question 18

What is a third degree AV block?

Answer 18

Complete Block – NO Signal between Atria and Ventricles
SA Node Still sends Signals but goes nowhere

Question 19

How do the ventricles respond to a 3rd degree AV block?

Answer 19

Ventricles have an Escape Pacemaker that initiates Ventricle Depolarization

Question 20

What is the relation between the ventricles and atria in a 3rd degree AV block?

Answer 20

Atria and Ventricles Depol at independent times and at different rates
Atria Faster
Ventricle – Bradycardic (30-45Bpm)

Question 21

How does a 3rd degree AV block appear on an ECG?

Answer 21

Appearance on ECG
P-P intervals are constant (atrial rate).
R-R intervals are constant (ventricular rate).
No consistent PR intervals.
QRS complex normal width or wide.

Question 22

Causes of third degree AV block?

Answer 22

Enhanced Vagal Tone
Toxicity of Cardioactive meds
Acute MI

Question 23

Symptoms of 3rd degree AV block?

Answer 23

Symptoms – Decreased Cardiac Output
Syncope
Light headedness
Apnea
Seizure
Possible death

Question 24

Treatment for 3rd degree AV block?

Answer 24

Acute MI? EMERGENCY!!
Meds? – adjust and remove drug causing block
Meds that help depress vagal tone
Atropine or isoproterenol