Intro/Bradycardia Modules

Question 1

What leads capture the...
1. Lateral
2. Inferior
3. Anteroseptal
4. Anterior
5. Anterolateral
part of the heart?

Answer 1

1. I, aVL
2. II, III, aVF
3. V1, V3
4. V3, V4
5. V5, V6

Question 2

How many electrodes are placed on the patient?

Answer 2

10

Generates 12 leads

Question 3

5 large squares =….

Answer 3

1 second

Question 4

How to calculate HR on ECH

Answer 4

Roughly: 300/# large squares

60/ R-R in msec

Question 5

P wave should be ___ in lead 2 and ___ in aVR when it is initiated by the SA node

Answer 5

Upright in lead 2

Downwards in aVR

Question 6

How wide is a normal PR interval?

Answer 6

< 200 msec (5 small squares)

Question 7

How wide is a normal QRS complex?

Answer 7

Less than 3 small squares

Question 8

Definitions of brady and tachycardia

Answer 8

Brady: < 60 BPM
Tachy: > 100 BPM

Question 9

Sinus bradycardia

Answer 9

< 60 BPM
Caused by any process that increases parasympathetic tone
Decreased automaticity of the SA node
Common causes: during sleep, increased vagal tone/vagal stimulation, hypothyroidism, hypothermia, brainstem herniation, myocarditis

Question 10

Ectopic atrial rhythm

Answer 10

Narrow complex rhythm that originates within atria but outside SA node
Will change the morphology of the P wave
Brady or tachycardia

Question 11

Premature atrial complexes

Answer 11

Irregular rhythm from an ectopic focus firing before SA node

The irregular rhythm usually has a predictable pattern (regularly irregular)

Question 12

First degree AV block

Answer 12

Prolonged PR interval
Length of PR interval remains constant
From a fixed but unusually long delay at the AV node
Not always bradyarrythmic

Question 13

2 types of second degree blocks

Answer 13

Mobitz type 1 (Wencheback)

Mobitz type 2

Question 14

Mobitz type 1 block

Answer 14

Progressively lengthening PR interval leading to failed conduction (missed beat)
Usually associated with disease at the AV node level

Question 15

Mobitz type 2 block

Answer 15

Constant PR interval that may be normal or prolonged with periodic missed beats
Usually associated with disease at the level of the His Bundle
More concerning because the backup after this level is really slow

Question 16

Third degree AV block

Answer 16

No electrical impulses conduct through the AV node or His bundle to the ventricles
Results in complete AV dissociation
P waves and QRS go at their own rates, just not coordinated