Week 3 Cardio Flashcards Preview

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Flashcards in Week 3 Cardio Deck (21)
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0
Q

What does a Q wave indicate?

A

Depolarisation of the septum

1
Q

What does a P wave indicate?

A

Atrial depolarisation

2
Q

What does an R wave indicate?

A

Main depolarisation of the ventricles

3
Q

What does an S wave indicate?

A

Depolarisation of the last remaining myocytes in the ventricles

4
Q

What does a T wave indicate?

A

Repolarisation of the ventricles

5
Q

What is the PQ interval?

A

The delay in conduction from the AV node to the ventricles

6
Q

What does the QT interval represent?

A

The time taken for depolarisation and Repolarisation of the ventricles
(Ventricular systole + diastole)

7
Q

What direction does depolarisation occur in the septum?

A

Base to apex, and left to right

8
Q

Why does the T wave record a positive deflection if it is a negative charge?

A

Repolarisation is negative, but because it is a negative charge moving towards a negative electrode, it records an upwards deflection

9
Q

What does isolectric mean?

A

No net movement of current. This can be either when the cell is either completely depolarised or completely repolarised.

10
Q

Where are the electrodes of lead 1 positioned?

A

Left arm and right arm

11
Q

Where are the electrodes of lead 2 positioned?

A

Left leg, right arm

12
Q

Where are the electrodes of lead 3 positioned?

A

Left arm, left leg

13
Q

What angle is lead 1?

A

Zero degrees

14
Q

What angle is lead 2?

A

60 degrees

15
Q

What angle is lead 3?

A

120 degrees

16
Q

What angle is aVF?

A

90 degrees

17
Q

What angle is aVR?

A

210 degrees

18
Q

What angle is aVL?

A

-30 degrees

19
Q

What does the ‘mean electrical axis of the heart’ refer to?

A

The direction where most of the flow of current is heading. This is calculated by the ECG machine and is recorded as the different deflections.

20
Q

What is a biphasic deflection?

A

When the current is moving approximately perpendicularly to the angle of the lead. It will record an upward and downward deflection