Electro Cardio Gram Theory Part 2

Question 1

Einthovens triangle
Depolarisation towards electrode causes ______
Depolarisation away electrode gives ________

Answer 1

Depolarisation towards Electrode gives / \
——. ——

Depolarisation away electrode gives
_____. ______
\/

Question 2

What does the PR interval represent

Answer 2

Atrial depolarisation along with the electrical activity being held at the AVN

Question 3

What creates an irregularly irregular rhythm

Answer 3

Atrial fibrillation

Question 4

If no P waves correlate with any of QRS complexes, the patient has what type of heart block (HB)?

Answer 4

3rd degree (complete) heart block

Question 5

What is the normal width of the QRS complex

Answer 5

80 - 110 ms

Question 6

What is the normal width of the PR interval

Answer 6

120 - 200 ms

Question 7

The boxes on the ECG paper are 1 mm and 5 mm in width. How many seconds does a 1 mm box represent?

Answer 7

1 mm (1 small square) = 0.04 seconds.

5 mm (5 small squares/ 1 big square) = 0.2 seconds
25 mm (5 big sqaures) = 1 second

Question 8

How can you calculate heart rate from an ECG

Answer 8

300 divided by the number of large squares in between consecutive R waves.

Example, if there are 5 large squares between two complexes, you would calculate by 300/5 = 60 beats per minute