13.8.2013(Leads)

Question 0

Location of aVL

Answer 0

-30

Question 1

Location of aVR

Answer 1

-150

Question 2

Location of aVF

Answer 2

90

Question 3

Placement of limb electrodes

Answer 3

Distal to shoulder and hip,not necessarily ankle and wrist

Question 4

Position when recording ECG

Answer 4

Supine

Upright or sitting position is not equivalent

Question 5

ECG changes when V1 and V2 are erroneously placed in 2nd intercostal space

Answer 5

Poor R wave progression
r’ waves with T wave inversion in V1 and V2
If the diaphragm is displaced downward as in COPD,deep S waves may be recorded

Question 6

Use of right sided precordial leads

Answer 6

Dextrocardia
Right ventricular hypertrophy
Right ventricular MI
Routinely measure if there is ST elevation in inferior leads

Question 7

Lewis lead

Answer 7

Rt arm electrode is moved to rt 2nd ICS
Lt arm electrode is moved to rt 4th ICS
Lead 1 is measured

Question 8

When is a Lewis lead used

Answer 8

When P waves are difficult to visualise

Question 9

Fontaine lead

Answer 9

Rt arm electrode is moved to manubrium

Lt arm electrode is moved to xiphisternum

Question 10

Use of Fontaine lead

Answer 10

To detect epsilon waves in arrythmogenic right ventricular dysplasia
Lead 1,2,3 are used for measurement

Question 11

Normal QRS axis in newborns upto 6months

Answer 11

+90

Question 12

Normal axis in adults

Answer 12

+90 to -30

Question 13

Lead 1 is perpendicular to

Answer 13

aVF

Question 14

Lead 2 is perpendicular to

Answer 14

aVL

Question 15

Lead 3 is perpendicular to

Answer 15

aVR

Question 16

R wave taller than S wave is normal in

Answer 16

Children

Question 17

Causes of tall R waves in V1

Answer 17

RBBB
Right ventricular hypertrophy
WPW
Straight posterior MI
Pacemaker rhythm 
Ventricular ectopic impulses

Question 18

Right ventricular hypertrophy

Answer 18

Rt axis deviation

Tall R waves in V1

Question 19

Tall R waves in V1 in WPW

Answer 19

Bypass tract is left sided

Question 20

Ventricular ectopic impulses showing tall R wave in V1

Answer 20

Impulse originates from lt ventricle

Question 21

Pacemaker QRS

Answer 21

Rt ventricular pacing- QS or rS in V1

Biventricular pacing- R or Rs in V1

Question 22

Causes of clockwise rotation of heart

Answer 22

Left ventricular hypertrophy
Rt ventricular hypertrophy in MS,PHT,COPD
COPD
biventricular hypertrophy
Acute pulmonary embolism
Left anterior fascicular block
Cardiac rotation due to mediastinal shifts,pectus excavatum