ECGs

Question 1

What does myocardial damage present as in an ECG?

Answer 1

A raised ST segment

Question 2

What leads represent the Lateral leads (left lateral wall)?

Answer 2

I, aVL, V5 and V6

Question 3

What leads represent the Inferior leads?

Answer 3

II, III and aVF

Question 4

What leads represent the Anterior leads?

Answer 4

V3 and V4

Question 5

What leads represent the Septal leads?

Answer 5

V1 and V2

Question 6

What axis does lead I compare?

Answer 6

aVR - aVL

Question 7

What axis does lead II compare?

Answer 7

aVR - aVF

Question 8

What axis does lead III compare?

Answer 8

aVL - aVF

Question 9

What is the major conduction pathway in the heart?

Answer 9

SA - AV - His - BB’s - Purkinje

Question 10

Why is lead II best to monitor?

Answer 10

Hearts depolarisation is in the same axis as the lead

Question 11

What mechanically does a p wave represent?

Answer 11

Atrial contraction

Question 12

What mechanically does the QRS complesx represent?

Answer 12

Ventricular contraction

Question 13

What mechanically does the T wave represent?

Answer 13

Relaxation of the myocardium

Question 14

How much time does one large box represent?

Answer 14

0.2 seconds

Question 15

How much time does one small box represent?

Answer 15

0.04 seconds

Question 16

What does the P-R interval represent?

Answer 16

The timescale of atrial activity

atrial depolarisation

Question 17

What does the QRS complex represent?

Answer 17

Time taken for full ventricular myocardium depolarisation

Question 18

What does the Q - T interval represent?

Answer 18

Total duration of ventricular activity (depolarisation and repolarisation)

Question 19

What lead is always negative in a normal ECG?

Answer 19

aVR

Question 20

What can ‘pathological q waves’ represent?

Answer 20

LBBB
aMI (late sign)
Scar tissue
Conduction issues

Question 21

What can an increased PR interval represent?

Answer 21

AV node blocks

Question 22

What can a decreased PR interval represent?

Answer 22

Wolff-Parkinson-White

Question 23

What can a prolonged QT interval lead to?

Answer 23

Torsades de Pointes

Question 24

What can pronlonged QRS intervals be a sign of?

Answer 24

Bundle Branch Blocks
PVC
Venricular Rhythms

Question 25

What does ST depression likely indicate?

Answer 25

Ischaemia (narrowing for a coronary artery)

Question 26

What does ST elevation likely indicate?

Answer 26

Necrosis of the myocardium

MI

Question 27

What occurs in sinus arrhythmia?

Answer 27

Sinus with a variable rate

HR increases with inspiration and decreases with expiration

Question 28

What causes sinus arrhytmia?

Answer 28

SA node pacemaker activity varies reflexively with respiration

Question 29

What is ‘p pulmonale’ and what does it indicate?

Answer 29

Tall peaked p wave indicating R atrium enlargement

Question 30

What is ‘p mitrale’ and what does it indiicate?

Answer 30

Broad notched p wave

indicating LA enlargement (mitral valve disease)

Question 31

Why does atrial fibrilliation occur?

Answer 31

Atrial depolarisation is disorganised leading to a chaotic ventricular rhythm

Question 32

What are some causes of AF?

Answer 32

Hypertension 
IHD 
Alcohol 
Mitral valve disease 
Myocarditis

Question 33

What ECG pattern is usually seen in atrial flutter?

Answer 33

Sawtooth pattern

Question 34

What 4 characteristics are generally seen in a pericarditic ECG?

Answer 34

• Widespread ST elevation
• ST elevation concave upward
• T wave inversion
• Lack of Q waves

Question 35

What is an atrial ectopic?

Answer 35

A premature discharge of an abnormal focus in either atrium

Question 36

What will an atrial ectopic look like on an ECG?

Answer 36

Earlier than expected

Abnormal confirmation

Question 37

When do junctional rhythms occur?

Answer 37

When electrical signal origionates further down the conduction system (near but not the AV node)