The Electrocardiogram

Question 1

QRS complex

Answer 1

initial ventricular activation

Question 2

ST segment

Answer 2

plateau of the action potential

Question 3

T wave

Answer 3

repolarization

Question 4

P wave

Answer 4

atrial depolarization - right atrium first then left atrium

sinus node is before the P wave but is too small to be recorded

Question 5

PR interval

Answer 5

from initiation of atrial to initiation of ventricular activation

Question 6

QT interval

Answer 6

sum of total AP in the ventricles

Question 7

Bipolar lead I

Answer 7

left arm (LA) minus right arm (RA) (left arm positive)

Question 8

Bipolar lead II

Answer 8

left leg (LL) minus right arm (RA) (LL positive)

Question 9

Bipolar lead III

Answer 9

left arm (LL) minus LA (LL positive)

Question 10

Which leads are the best to see P waves?

Answer 10

II and VI

Question 11

Which leads are the best to see the anterior part of the left ventricle?

Answer 11

leads V1 - V4

Question 12

Which leads are the best to see the lateral part of the left ventricle?

Answer 12

leads I, aVL, V4 - v6

Question 13

Which leads are the best to see the inferior part of the left ventricle?

Answer 13

leads II, III, and aVF

Question 14

Burger’s Triangle

Answer 14

a squalene triangle that describes the positioning of the leads in regards to the body and the heart

however, this makes calculations difficult, so an equilateral triangle is used instead

Question 15

Einthoven’s Triangle

Answer 15

a representation of the limb leads using an equilateral triangle to make calculations easier