12 lead 2

Question 1

Causes of widened QRS

Answer 1

1. bundle branch block

2. ectopic ventricular beat

Question 2

right bundle branch block displays

Answer 2

1. widened QRS
2. tall, upright (positive) in right sided leaded
3. negative in left sided leads
4. late forces to the right ventricle
5. Positive in V1 and V2
6. negative in I and V6

Question 3

left bundle branch block displats

Answer 3

1. widened QRS away from V1 and toward V6
2. high voltage generated in the LV
3. forces are away from the right sided leads (v1)
4. forces are toward the left sided leads (V6)

Question 4

hemiblocks cause

Answer 4

axis shifts without widening the QRS

Question 5

in a normal axis, which leads are upright

Answer 5

Leads 1 and 2 are upright

Question 6

in a left axis deviation with left anterior hemiblock,

Answer 6

Lead 1 is positive

Lead 2 is markedly negative

Question 7

right axis deviation with left posterior hemiblock,

Answer 7

Lead I is markedly negative and Lead 2 is positive

Question 8

____ cause axis shifts

Answer 8

distal block in the left bundle

Question 9

___ cause left axis deviation

Answer 9

anterior fascicle

Question 10

____ cause right axis deviation

Answer 10

posterior fascicle blocks

Question 11

Left ventricular hypertrophy causes

Answer 11

1. large positive deflections (R waves in V5 & V6 (lt. sided leads)
2. large negative deflections (S waves) in V1 (rt. sided lead).
3. normal QRS duration with very high voltage

Question 12

Ischemia to due sudden high Oxygen demand in the presence of fixed coronary obstruction causes

Answer 12

depression of the ST segment

Question 13

Ischemia due to acute coronary artery obstruction during low oxygen demand causes

Answer 13

T wave inversion

Question 14

exercise test in a pt with fixed stenosis of coronary artery will result in

Answer 14

1. normal resting ST segment

2. with exertion, ST depression due to transient ischemia

Question 15

Axis shift?

Answer 15

1. Right axis -
   RVH or posterior hemiblock
2. Left axis -
   LVH or anterior hemiblock

Question 16

ST elevation?

Answer 16

injury if localized or pericarditis if diffuse

Question 17

ST depression?

Answer 17

ischemia or subendocardial infarct

Question 18

T inversion?

Answer 18

ischemia or secondary to hypertrophy or bundle block

Question 19

Long QT?

Answer 19

consider electrolyte imbalance, drug effect

Question 20

Why is the QRS widened in Right bundle branch block?

Answer 20

1. tall, wide terminal R waves in V1 and V2
2. Wide S waves in I and V6
3. terminal forces are the the right

Question 21

acute pericarditis

Answer 21

1. diffuse ST elevations in multiple leads

2. no localization

Question 22

Acute anterior MI

Answer 22

1. ST elevations

2. Q waves in anterior leads (V1-V4)

Question 23

acute inferior MI

Answer 23

1. ST elevations
2. Q waves in inferior leads (II, III, aVF)
3. reciprocal ST depression in anterior leads (V2, V3)