EKG

Question 1

what leads do you look at for BBB

Answer 1

V1 (V2) and V6 (V5)

Question 2

causes of right BBB

Answer 2

• normal
• rate related (if HR is high especially in paroxysmal)
• CAD
• Ventricular hypertrophy
• aberrant ventricular conduction
• Congenitial heart disease
• Acute dilation of the RV
• MI
• conduction system disease
  not as ominous as left BBB

Question 3

Causes of Left BBB

Answer 3

more ominous than right BBB
- MI or ischemia
- congestive heart failure 
- quinidine 
- occasionally seen in normal individuals 
- HTN 
-Conduction system disease 
- cardiomyopathy 
- Severe AS 
if patient has CP and new LBBB needs to go to cath immediately because it is difficult to see ST changes with LBBB

Question 4

Causes of left ventricular enlargement

Answer 4

• chronic HTN
• cardiomyopathy/CHF
• chronic mitral regurgitation
• chronic aortic stenosis/ regurgitation
• VSD with pulmonary HTN
• obesity
• cocaine
• anabolic steriods
• extreme athletic conditioning

Question 5

Calculating HR with the box method

Answer 5

1 box- 300
2 boxes- 150
3 boxes- 100
4 boxes- 75
5 boxes- 60
6 boxes 50

Question 6

P wave

Answer 6

small rounded upright wave ( atrial depolarization)

Question 7

Q wave

Answer 7

first negative deflection after a P wave

Question 8

R wave

Answer 8

first positive deflection after a p wave

Question 9

s wave

Answer 9

first negative deflection after an r wave

Question 10

ST segment elevation means

Answer 10

injury

Question 11

ST segment depression means

Answer 11

ischemia

Question 12

Lead 1 has a positive electrode…

Answer 12

left arm– perpendicular, a little up a little down

Question 13

lead II has a positive electrode

Answer 13

left foot, positive QRS, electrical forces towards the positive

Question 14

Lead III has a positive electrode

Answer 14

left foot upward positive QRS

Question 15

Lead aVR has a positive electrode

Answer 15

right arm, QRS negative deflection, away from the positive electrode… P and T wave inverted is normal

Question 16

Lead aVL has a positive electrode

Answer 16

on the left arm… perpendicular biphasic QRS alittle up and a little down

Question 17

Lead aVF has a positive electrode

Answer 17

on the left foot, positive QRS

Question 18

Inferior leads

Answer 18

II, III, aVF ( all have a positive electrode on the left foot), RCA (in the majority of people)

Question 19

Lateral leads (high lateral)

Answer 19

I, aVL (positive electrode is on the left arm) left circumflex in the majority of people

Question 20

Septal leads

Answer 20

V1 V2, LAD

Question 21

Anterior Leads

Answer 21

V3, V4, LAD

Question 22

Low lateral leads

Answer 22

V5, V6, left circumflex in the majority of people

Question 23

What leads do you look at for axis determination

Answer 23

Lead I and aVF

Question 24

Normal axis

Answer 24

Lead I positive avF positive

Question 25

Left axis deviation

Answer 25

Lead 1 positive, aVF negative

Question 26

indeterminate axis

Answer 26

lead I negative and aVF negative

Question 27

Right axis deviation

Answer 27

Lead I negative and aVF positive

Question 28

Causes of Left axis deviation

Answer 28

• Normal
• LBBB
• Left anterior hemiblock
• inferior wall MI
• Left ventricular hypertrophy
• cardiomyopathies
• congenitial heart disease
• severe pulmonary disease
• aberrant ventricular
  conduction

Question 29

Causes of right axis deviation

Answer 29

• normal
• right BBB
• Left posterior hemiblock
• right ventricular hypertrophy
• anterolateral MI
• Severe pulmonary disease
• aberrant ventricular conduction
• reversal of right and left arm leads

Question 30

posterior wall leads

Answer 30

V1 V2 mirror image changes, posterior descending artery (PDA)