ECG 12 Lead Interpretation

Question 1

Where do the limb leads go?

Answer 1

Arms and legs ( white to right, red to bed, smoke over fire, snow over trees)

Question 2

Where does V1 & V2 go?

Answer 2

Each side of the sternum at the 4th intercostal space

Question 3

Where does V4 & V5 go?

Answer 3

Intercostal space, mid clavicular line (directly under the nipple)

Question 4

Where does V3 go?

Answer 4

between V2 and V4

Question 5

Where does V6 go?

Answer 5

mid-axillary line

Question 6

what is the ST segment measured by?

Answer 6

the J point to the beginning of T wave

Question 7

How many mm of elevation needs to be in V1-V3 for an MI?

Answer 7

2mm (2 small boxes)

Question 8

How many mm of elevation needs to be in all other leads for an MI?

Answer 8

1mm (one small box)

Question 9

Any ST segment under the baseline is considered DEPRESSION. True or false?

Answer 9

TRUE.

Question 10

What do tombstones on an ECG mean?

Answer 10

LARGE MI

Question 11

What are signs of ischemia in the heart?

Answer 11

ST elevation or depression
ST segment flat or downward

Question 12

What are the different MI’s called?

Answer 12

Posterior
Inferior
Later
Anterior
Septal
——> Any combination of these all

Question 13

What does oxygen deprivation to the heart do?

Answer 13

alter its function!
- initiates anaerobic metabolism (production of energy without O2
- acidosis which is ineffective for cell function
- cells begins to suffer injury and will die if normal circulation and oxygenation are not restored (drowning man)

Question 14

Ischemia and injury are both ________ meanwhile infarct is _______ !!!!!!!

Answer 14

REVERSIBLE
IRREVERSIBLE

Question 15

What are the three protective mechanisms of the heart?

Answer 15

1. collateral circulation, perfusion overlaps in diff arteries!
2. oxygen from ventricles can diffuse into cells nearby tissue
3. there may be some small vessels (thebesian veins) arising directly from the ventricles!

Question 16

What does cardiac ischemia cause in the ECG?

Answer 16

ST depression and possible flipped T wave, causes repolarization to occur along an abnormal path

Question 17

What does cardiac injury cause in the ECG?

Answer 17

• leading to ST elevation, because it remains more positive than surrounding tissue
• flipped T wave as well

Question 18

What does infarction in the heart mean?

Answer 18

DEAD tissue, no action potentials!!!

Question 19

What is a reciprocal change?

Answer 19

A mirror image that occurs when two electrodes view same AMI from opposite angles!!!

Question 20

What does the right coronary artery supply?

Answer 20

RV, RA, SA and AV nodes (regulate HR)

Question 21

What does the left coronary artery supply?

Answer 21

LV and LA, front and left side of the heart

Question 22

What is a right ventricular AMI?

Answer 22

When the RV is infarcted!

Question 23

Up to ___ % of Inferior Mi will have RVI!

Answer 23

50!!!

Question 24

When do you do a 15 lead ECG?

Answer 24

• helps diagnose posterior STEMIs
• direct changes occurring in the RV are seen clearly in V4R
• anytime you see an inferior MI obtain right sided leads

Question 25

How do you perform a 15 lead?

Answer 25

Move leads V4, V5, and V6 to the back and they become V7, V8 and V9!

Question 26

What can we do for STEMI’s??

Answer 26

1. Full assessment- QUESTIONS!!!!
2. Full set of vitals (12 lead too)
3. O2 if required
4. Rule in/out ASA
5. Rule in/out nitro (OUT; hypotensive, RV involvement)
6. If STEMI present, apply defib pads immediately
   TRANSPORT QUICKKKKK

Question 27

Contraindications of STEMI bypass protocol include:

Answer 27

CTAS 1 pts who medics cannot secure airway or ventilate

12 lead - LBBB, Ventricular paces rhythm or STEMI mimics

transport is >60 mins from pt contact

pt is experiencing a compilation requiring PCP diversions:
- moderate-severe resp distress or use of CPAP
- hemodynamic instability or SBP <90mmHG sys at ANY point

VSA w/o ROSC