Reading an ECG

Question 1

What is a normal heart rate?

Answer 1

60-100 bpm

Question 2

When is a heart rate tachycardic?

Answer 2

>100bpm

Question 3

When is a heart rate bradycardic?

Answer 3

<60bpm

Question 4

How can a heart rate be calculated on a normal ECG?

Answer 4

Count the number of large squares present within one R-R interval. Divide 300 by this number to calculate heart rate. Example: - 4 large squares in an R-R interval - 300/4 = 75 beats per minute

Question 5

What are the 2 types of irregular heart beats?

Answer 5

1. Regularly irregular 2. Irregularly irregular

Question 6

Describe regularly irregular

Answer 6

a recurrent pattern of irregularity

Question 7

Describe irregularly irregular

Answer 7

completely disorganised

Question 8

Photo of normal ECG

Answer 8

NEEDED

Question 9

What represents the T wave?

Answer 9

Ventricular diastole

Question 10

What represents the QRS complex?

Answer 10

Ventricular systole

Question 11

What represents the P wave?

Answer 11

Atrial systole

Question 12

What represents the dicrotic notch?

Answer 12

Closure of SL valves

Question 13

What does a P wave with a chaotic baseline indicate?

Answer 13

fibrillation waves

Question 14

What does a P wave with a sawtooth baseline indicate?

Answer 14

flutter waves

Question 15

What does a flat line p wave indicate?

Answer 15

no atrial activity at all

Question 16

What is a suggested diagnosis of absent P waves and irregular rhythm?

Answer 16

Atrial fibrillation

Question 17

How long should the PR interval be?

Answer 17

120-200 ms (3-5 small squares).

Question 18

What does the presence of a prolonged PR interval suggest?

Answer 18

Presence of AV delay (AV block)

Question 19

Describe the PR interval during first-degree heart block (AV block)

Answer 19

a fixed prolonged PR interval (>200 ms)

Question 20

What is complete heart block?

Answer 20

third-degree heart block occurs when there is no electrical communication between the atria and ventricles due to a complete failure of conduction

Question 21

Describe an ECG of complete heart block

Answer 21

the presence of P waves and QRS complexes that have no association with each other, due to the atria and ventricles functioning independently

Question 22

Where does first-degree AV block occur?

Answer 22

Between the SA node and AV node (within the atrium)

Question 23

Where does third-degree (total) AV block occur?

Answer 23

Occurs at or after the AV node resulting in a complete blockade of distal conduction

Question 24

What is a normal explanation for a shortened PR interval?

Answer 24

P wave is originating from somewhere closer to the AV node so the conduction takes less time (the SA node is not in a fixed place and some people’s atria are smaller than others)

Question 25

What is a medical diagnosis for a shortened PR interval?

Answer 25

The atrial impulse is getting to the ventricle by a faster shortcut instead of conducting slowly across the atrial wall (accessory pathway)