ECG Flashcards
Where are the 6 chest (precordial) leads placed?
1 - 4th intercostal space on the right side of the sternum
2- 4th intercostal space on the left side of the sternum
3- between 2 &4
4 - 5th intercostal space, mid-clavicular line
5 - 5th intercostal space, anterior axillary line
6 - 5th intercostal space, mid axillary line
Where are the 4 limb leads placed?
Red - right arm
Yellow - left arm
Green - left leg
Black - right leg
What is the normal range for the PR interval?
0.12 to 0.2 seconds
3-5 small boxes
What is the normal range for the QRS complex?
<0.10 seconds
2 small boxes/ or less than 3 small boxes
What is the normal angle of the axis?
+9 to -30 degrees
What effect does inspiration have on vagal tone?
Inspiration decreases the vagal tone
What is meant by a lead?
A lead means an electrical picture of the heart
sometimes the term is used to describe the wires
Why is it called a 12-lead ECG?
The ECG is made up of 12 characteristic views of the heart (six obtained from the limb leads (4 physical leads) and six from the chest leads)
What plane do the limb leads look at the heart?
The limb leads look at the heart in a vertical plane
What plane do the chest leads look at the heart?
The chest leads look at the heart in a horizontal plane
How big are large squares and how many seconds do they represent?
Large squares are 5mm and 0.2 seconds
Small squares are 1mm and 0.04 seconds
What causes right and left axis deviation?
Right ventricular hypertrophy (RVH) causes right axis deviation
Left ventricular hypertrophy (LVH) causes left axis deviation
