# ECG's Flashcards Preview

## Respiratory and Cardio > ECG's > Flashcards

Flashcards in ECG's Deck (15)
1
Q

what are the squares representative of in an ECG?

A

small square = 40ms

big square = 0.2s secs

2
Q

how many bipolar leads are there and what do they do?

A

record electrical activity in 2 directions
(wrist, wrist, ankle)

3
Q

how many unipolar arm leads are there and what do they do?

A

looks at electricity going too?
(shoulder, shoulder, abdomen)

4
Q

how many unipolar chest leads are there and what do they do?

A

looks at incoming electrical activity, starts on the right and moves down and to the left

5
Q

which leads assess electricity within the lateral myocardial territory?

A

leads 1, aVL, V5 and V6

6
Q

A

aVR

7
Q

what are the 3 main peaks of the ECG waveform?

A
```P = atrial depolarisation
QRS = ventricular depolarisation (+ve if travelling toward, -ve if moving away)
T = ventricular repolarisation```
8
Q

which waves are always positive except on the aVR?

A

P waves and T waves except on the aVR.

9
Q

QRS waves face upwards on which side?

A

the left (positive)

10
Q

QRS waves face downwards on which side?

A

the right (negative)

11
Q

what is the P wave?

A

atrial depolarisation, SA node sends an impulse into the atria causing a contraction.
AV node sends a signal to the ventricles down His-Purkinje systems, slows conduction causing the PR interval.

12
Q

what is the QRS complex?

A

takes up to 120ms (3 small squares) shows ventricular depolarisation.

13
Q

what is the ST segement?

A

represents interval between depolarisation and repolarisation.

14
Q

what is the T wave?

A

represents ventricular repolarisation

15
Q

what is the QT interval?

A

represents time of depolarisation + repolarisation