Electrophysiology *

Question 1

What is the depolarization sequence?

Answer 1

SA node > AV node > Bundle of His > Left & Right Branches > Purkinje Fibres > Ventricular Fibres

Question 2

What is the P wave?

Answer 2

It is atrial depolarization/systole.

Question 3

What is the PR interval?

Answer 3

It’s the beginning of the P wave and goes to the QRS complex. It’s the time it takes for the impulse to go from SA node to the purkinje fibres. It’s the interval of time between atrial and ventricular depolarization.

Question 4

What is the QRS complex?

Answer 4

It’s ventricular depolarization, (systole) and atrial depolarization (diastole)

Question 5

What is the ST segment?

Answer 5

It’s the beginning of ventricular depolarization/diastole. It’s the end of the QRS complex, and goes to the beginning of the T wave.

Question 6

What is the J point?

Answer 6

It’s the end of the QRS complex and beginning of the ST segment.

Question 7

What is the T wave?

Answer 7

It’s ventricular repolarization/diastole.

Question 8

What is the QT Interval?

Answer 8

It’s the length of time for ventricular depolarization and repolarization. Begins at Q and ends at the end of T wave. (Longest amount of time)

Question 9

What are U waves?

Answer 9

Not always present, unless HR is slow. It follows the T wave and is smaller.

Question 10

What’s the ISOelectric line?

Answer 10

It’s the horizontal line between cardiac cycles.

Question 11

What is a 12 lead ECG?

Answer 11

It obtains 12 views of the heart.

Question 12

What does the lead system record?

Answer 12

The differences between left arm, right arm and left leg.

Question 13

What is lead one?

Answer 13

It’s the result of the difference between right and left arm. It’s the starting point.

Question 14

What’s lead 2?

Answer 14

Difference between left leg and right arm.

Question 15

What’s lead three?

Answer 15

Difference between left leg and left arm.

Question 16

What is Einthoven’s triangle?

Answer 16

It’s the axis of 3 leads forming an equilateral triangle with the heart in the centre. It’s used for HR

Question 17

What’s aVR?

Answer 17

It’s an augmented limb. It’s a right sided lead. Looks down at the heart from the right shoulder?

Question 18

What’s aVL?

Answer 18

Left sided lead – lateral lead.

Question 19

What’s aVF?

Answer 19

In an inferior/perpendicularly

Question 20

What are precordial leads?

Answer 20

V1-V6. Unipolar leads that are in the transverse/horizontal plane

Question 21

Where is V1?

Answer 21

It’s at the 4th intercostal space to the right of the sternum.

Question 22

Where’s V2?

Answer 22

4th intercostal space. Left of sternum

Question 23

Where’s V3?

Answer 23

Midway between V2 and V4.

Question 24

Where’s V4?

Answer 24

Midclavicular line – 5th intercostal space.

Question 25

Where’s V5?

Answer 25

Anterior axillary line. Same level as v4.

Question 26

Where’s V6!

Answer 26

Midaxillary line. Same level as V4.

Question 27

What are the inferior leads?

Answer 27

11, 3 and aVF

Question 28

What are the septal leads?

Answer 28

V1 and V2

Question 29

What are the anterior leads?

Answer 29

V2 to V4.

Question 30

What are the lateral leads?

Answer 30

Precordial leads: V4-V6.

High lateral: 1, aVL.

Question 31

What do 5 large boxes equal?

Answer 31

1 second.

Question 32

What do 30 large boxes equal?

Answer 32

6 seconds.

Question 33

What’s the voltage measurement of r?

Answer 33

21 mm

Question 34

What’s the voltage measure of Q?

Answer 34

4 mm

Question 35

What’s the voltage measurement of S?

Answer 35

7.5 mm

Question 36

What’s the R to R cycle?

Answer 36

Ventricular rate

Question 37

What’s the P to P cycle?

Answer 37

Atrial rate

Question 38

What’s the 6 s method to calculate heart rate?

Answer 38

Count the number of RRI IN 6 seconds and multiply by 10.

Question 39

What’s the large box method?

Answer 39

Locate 2 consecutive R waves. Count the number of large boxes between them and divide by 300.

Question 40

What’s small box method?

Answer 40

Count number of small boxes between 2 R waves and divide into 1500.

Question 41

What’s the duration between R waves method?

Answer 41

Count the duration in seconds between 2 waves and divide this number into 60.