ECG

Question 1

ECG allows clinicians to monitor how the wave of excitation moves through heart tissue. True or false?

Answer 1

True

Question 2

How does an ECG work?

Answer 2

It detects very small differences in electrical potential at two points in the body due to movement of cellular depolarisation along the axis of measurement points

Question 3

What does a P wave show?

Answer 3

Atrial depolarisation

Question 4

What does the QRS complex show?

Answer 4

Ventricular contraction

Question 5

What does a T wave show?

Answer 5

Ventricular repolarisation

Question 6

How long is a normal PQ interval?

Answer 6

0.12-0.20 seconds

Question 7

What may a PQ interval longer than 0.20 seconds indicate?

Answer 7

AV block

Question 8

What may a PQ interval shorter than 0.12 seconds indicate?

Answer 8

WPW syndrome

Question 9

How long is a normal QT interval?

Answer 9

<0.46 seconds

Question 10

Why is a prolonged QT interval dangerous?

Answer 10

Because if a new depolarisation cycle arrives before cells are repolarised, there is a risk of ventricular fibrillation

Question 11

ST elevation is important in the diagnosis of what conditions?

Answer 11

Ischaemia and myocardial infarctions (STEMI, NSTEMI)