clinical tx of arrhythmia

Question 1

Initiation of the cardiac cycle normally begins with

Answer 1

initiation of the impulse at the sinoatrial (SA) node.
A resulting wave of depolarization passes through the right and left atria, which produces the P wave on the surface ECG and stimulates atrial contraction.

Question 2

Following activation of the atria, the impulse proceeds to the:

Answer 2

atrioventricular (AV) node, which is the only normal conduction pathway between the atria and the ventricles.

Question 3

The AV node functions to

Answer 3

slows impulse conduction which allows time for contraction of the atria and the pumping of blood from the atria to the ventricles prior to ventricular contraction.

Question 4

______ accounts for most of the duration of the PR interval.

Answer 4

Conduction time through the AV node

Question 5

bundle of His is a

Answer 5

small portion of the last part of the PR interval

Question 6

what produces a P wave on the surface ECG

Answer 6

A resulting wave of depolarization passes through the right and left atria, which produces the P wave on the surface ECG and stimulates atrial contraction.

Question 7

The QRS complex on the ECG represents the

Answer 7

depolarization of the ventricular muscle mass.

Question 8

The T wave on the ECG represents the

Answer 8

repolarization and relaxation of the ventricles.

Question 9

Atrial repolarization and relaxation occurs during the QRS complex.

Answer 9

QRS complex.

Question 10

types of arrhythmias

Answer 10

1. bradyarrhythmia (too slow)

2. tachyarrhythmia (too fast)

Question 11

Bradyarrhythmias: Where in the conduction system can problems develop?

Answer 11

1. Sinus node
2. AV node
3. below the AV node

Question 12

Bradyarrhythmia: sinus node dysnfuction

Answer 12

1. sinus bradycardia
2. sinus arrest/pause
3. tachy-brady syndrome
4. chronotropic incompetence

Question 13

chronotropic incompetence

is

Answer 13

the inability to mount age-appropriate HR with exercise

Question 14

Sinus Bradycardia is

Answer 14

Persistent slow rate from the SA node.

Question 15

Sinus Bradycardia rate

Answer 15

less than 60 bpm (~55)

Question 16

sinus bradycardia PR interval is

Answer 16

180 ms (.18 sec)

Question 17

Sinus arrest is

Answer 17

1. failure of sinus node discharge resulting in absence of atrial depolarization and period of ventricular asystole
2. no relationship between the pause and the basic cycle length

Question 18

sinus arrest rate:

Answer 18

75 bpm

Question 19

sinus arrest PR interval

Answer 19

180 ms

Question 20

sinus arrest, how long is an arrest

Answer 20

2.8 second arrest

Question 21

Sinus Node Dysfunction – Bradycardia-Tachycardia (Brady-Tachy) Syndrome

Answer 21

1. intermittent episodes of slow and fast rates from the SA node or atria
2. occurs when the SA node has alternating periods of firing too slowly and too fast
3. often manifests in period of atrial tachycardia, flutter or fibrialltion
4. cessation of tachycardia is often followed by long pauses from the SA node

Question 22

Sinus Node Dysfunction – Bradycardia-Tachycardia (Brady-Tachy) Syndrome:
rate during bradycardia:

Answer 22

43 bpm

Question 23

Sinus Node Dysfunction – Bradycardia-Tachycardia (Brady-Tachy) Syndrome: rate during tachycardia?

Answer 23

130 bpm

Question 24

Bradyarrhythmias: AV node

Answer 24

1. first degree AV block

2. Mobitz I 2nd degree AV block (Wenkebach)

Question 25

first degree AV block is

Answer 25

1. AV conduction is delayed and the PR interval is prolonged (>200 ms or .2 sec)
2. delay in the AV conduction but each atrial signal is conducted to the ventricles in a 1:1 ratio

Question 26

1st degree AV block rate:

Answer 26

79 bpm

Question 27

1st degree AV block PR interval

Answer 27

340 ms

Question 28

2nd degree AV Block: Mobitz I (wenckebach)

Answer 28

1. progressive prolongation of the PR interval until a ventricular beat is dropped
2. characterized by intermittent failure of atrial depolarizations to reach the ventricle
3. 2 patterns of 2nd degree AV block
   4.

Question 29

2nd degree AV Block: Mobitz I (wenckebach): Ventricular rate is

Answer 29

irregular

Question 30

2nd degree AV Block: Mobitz I (wenckebach): atrial rate is

Answer 30

90bpm

Question 31

2nd degree AV Block: Mobitz I (wenckebach): PR interval is

Answer 31

progressively longer until a P wave fails to conduct

Question 32

Wenckebach or Mobitz Type I block is marked by

Answer 32

progressive prolongation of the PR interval in cycles preceding a dropped beat.

Question 33

The_____ is most commonly the site of Mobitz I block.

Answer 33

AV node

The QRS duration is usually normal.