Myocardial ischemia and infarction

Question 1

What is the terrible triad

Answer 1

Ischemia
Injury
Infarction

Question 2

What is ischemia? How does it appear on an ECG

Answer 2

Poor blood supply and hypoxia

Inverted T-waves

Question 3

Is ischemia reversible

Answer 3

yes

Question 4

How quickly does ischemia occur in an MI

Answer 4

within seconds of onset

Question 5

Injury may appear which 2 ways on an ECG

Answer 5

Elevated ST Segment

Depressed ST segment

Question 6

How does infarction appear on an ECG

Answer 6

Abnormal Q waves + QRS Complexes

Can also have increased R waves

Question 7

Is infarction reversible?

Answer 7

No

Question 8

Infarction occurs ____ after onset

Answer 8

2 hours after

Question 9

Is injury reversible

Answer 9

yes

Question 10

When does injury occur

Answer 10

20-40 mins

Question 11

Bradycardia = ___BPM

Answer 11

<60bpm

Question 12

Tachycardia = ___ BPM

Answer 12

> 100 bpm

Question 13

What causes a 1st degree AV block

Answer 13

Prolonged conduction in AV node (PR interval >0.02s)

Question 14

What does the P-wave look like in a 1st degree AV block

Answer 14

normal

Question 15

how many types of 2nd degree AV block are there? what are they?

Answer 15

2
MOBITZ Type 1 (Wenckeback): Block occurs at AV node and is transient
MOBITZ Type 2: Block occurs at bundle branches/bundle of His

Question 16

How does a type 1 second degree AV block appear on an ECG

Answer 16

PR lengthens until totally blocked - no QRS follows a P causing a missed beat

Question 17

How does a type 2 second degree AV block appear on an ECG

Answer 17

Abrupt drop of QRS, but PR interval normal

Question 18

What is a 3rd degree AV block

Answer 18

Block at at AV node, bundle of His OR bundle branches

complete disassociation between atria and ventricles - independent atrial and ventricular rate (atrial faster)

Question 19

How does a 3rd degree bundle branch block appear on an ECG

Answer 19

QRS is longer