ecg

Question 1

what is an ecg

Answer 1

• Representa electrical events of cardiac cycle detected by placing electrodes on the surface of the body
• Summation of electrical activity

Question 2

what are the 3 basic laws on ECG

Answer 2

• A positive complex is formed in depolarisation, when the lead is in the direction of flow
• A negative complex is formed in repolarisation, when the lead is against the direction of flow
• If the lead is at 90 degrees to the wave
  of depolarisation, then you get a biphasic waveform.
  The initial part is if it goes towards the lead
  and then goes away from the lead.

Question 3

what is the difference between bipolar leeds adn unipolar leeds

Answer 3

*Bipolar leads measures from two points on the actual surface
* 1 lead on th body with a virtual reference point with 0 electrical potential located in centre of heart

Question 4

what are the 12 leads of a standard ECG

Answer 4

• 3 bipolar: I,II,III
• 3 Augmented unipolar: AVR, AVL, AVF
• 6 Unipolar precordial leads

Question 5

what is the direcion of bipolar lead 1

Answer 5

• R arm to L arm
• depol will be positive
• repol will be negative

Question 6

what is the direction of bipolar lead II

Answer 6

• right arm to Left leg
• positive deflection in both the P waves and the QRS
  complexes

Question 7

what is the direction of biploar lead III

Answer 7

• Left arm to Left leg

Question 8

what are the plasments of the augmented unipolar leads: AVR, AVL, AVF

Answer 8

• AVR = right shoulder
• AVL = left shoulder
• AVF = over pubic symph

Question 9

Hexaxial reference system I - 0 degrees

II - __ degrees
III - ___ degrees
aVR - ___ degrees
aVL - ___ degrees
aVF - ____degrees

Answer 9

II - 60 degrees
III - 120 degrees
aVR - 210 degrees
aVL - 30 degrees
aVF - 90 degrees

Question 10

what do V1 and V2 leads look at

Answer 10

left ventricle + left inter ventricular septum septum

Question 11

what do v3 and v4 leads look at

Answer 11

anteroir wall

Question 12

what are v5 and v6 looking at

Answer 12

lateral wall

Question 13

what is the P wave

Answer 13

Atrial depol from SA node

Question 14

what is QRS complex

Answer 14

• Ventricular depol at apex of heart
• Atrial repol

Question 15

what is the T wave

Answer 15

Ventricular repol

Question 16

P waves are always __ in leads I and II

a)+ve
b)-ve

Answer 16

a

Question 17

P wave are always __ in AVR lead

a) +ve
b)-ve

Answer 17

b

Question 18

how many mm per second

Answer 18

25

Question 19

how many mm is 1 mV

Answer 19

10mm

Question 20

In a normal electrocardiogram (ECG), the PR interval should typically fall within which of the following ranges?

A) 0.12 to 0.20 seconds
B) 0.20 to 0.30 seconds
C) 1.0 to 1.5 seconds
D) 2.0 to 2.5 seconds

Answer 20

a

Question 21

what is a long PR interval indicitive of

Answer 21

1st degree heart block

Question 22

a noral T wave is

a) symetrical
b) asymetrical

Answer 22

b

Question 23

in a normal ECG how do you calc HR

Answer 23

300/ big squares between R-R complex

Question 24

Width of deflection reflects speed of ________

Answer 24

conduction

Question 25

Positive deflection is towards the _______

Answer 25

lead/vector

Question 26

what would cause a PR interval to be shorter

Answer 26

in younger patients or in Wolf-Parkinson-White syndrome

Question 27

what does a broad QRS complex indicate

Answer 27

* Ventricular conduction delay / bundle branch block * Pre-excitation

Question 28

what does a small QRS complex inidicate

Answer 28

* Obese patient * Pericardial effusion * Infiltrative cardiac disease

Question 29

The P waves should be upright and there should be no Q waves or only a small in which leads

Answer 29

* I * II * V2 * V6

Question 30

All waves are negative in lead ___

Answer 30

AVR

Question 31

how can Hyperkalaemia present on an ECG

Answer 31

* Tall T waves * flattenied P waves * broad QRS * eventually ‘sine wave pattern’

Question 32

how can Hypokalaemia present on an ecg

Answer 32

* Flattened T wave * QT prolonged

Question 33

how can **Hypercalcaemia** present on an ECG

Answer 33

QT shortening

Question 34

how can **Hypocalcaemia** present on an ECG

Answer 34

* QT prolongation

Question 35

what could a low amplitude p wave indicate

Answer 35

Atrial fibrosis Obesity Hyperkalaemia

Question 36

what could a broad and bifid P wave indicate

Answer 36

Left atrial enlargement

Question 36

what could a high amplite p wave indicate

Answer 36

atrial enlargments

Question 37

what could a tall QRS complex indicate

Answer 37

left ventricular hypertrophy

Question 38

T wave is usually inverted in which leads

Answer 38

aVR and can be in III

Question 39

The R wave must grow from V_ to atleast V_

Answer 39

1 to 4

Question 40

what are ectopic beats

Answer 40

* Very Common * Non sustained beats arising from ectopic regions of atria or ventricles * Generally benign * High burden VE can cause heart failure * High burden AE can progress to AF

Question 41

Male with chadsvasc score of one, would you treat and what with

Answer 41

yes anticoag (warfarin/doac)

Question 42

female with chadsvasc score of 1 would you treat

Answer 42

no

Question 43

what shape in the ecg does a right bundle block make

Answer 43

M QRS complex acronym **M**a**RR**ow

Question 44

what shape in the ECG does a left bundle block make

Answer 44

W QRS acronym **W**I**LL**iam

Question 45

what are some possible conditions for black outs

Answer 45

Conduction disease/bradycardia/ Extreme tachycardia

Question 46

what are some possible conditions for chest pain

Answer 46

pericarditis, MI