Myocardial infarction

Question 1

Myocardial infraction

Answer 1

-essentially end stage of coronary artery disease

Question 2

NSTEMI

Answer 2

partial occlusion of a major artery

Question 3

Myocardial infraction is _____ onset

Answer 3

acute

Question 4

STEMI means…

Answer 4

S-T segment elevation MI

Question 5

body has a few hours of oxygen deprivation before

Answer 5

cardiac cells die

Question 6

Path of myocardial infraction

Answer 6

• atherosclerosis
• complicated lesion
• ischemia -therefore no oxygen to the heart (cardiac hypoxia)
• anaerobic metabolism
• acidosis (alters ph, which alters potential for heart to contract)
• arrythmias (irregular pattern beating)
• decreased ability to pump
• necrosis of heart muscle (infarction)

Question 7

larger vessels are _______

smaller vessels are ______

Answer 7

• proximal vessels

- distal vessels

Question 8

Etiology of myocardial infarction

Answer 8

• mostly atherosclerosis
• thrombus may be responsible (can develop there or come through as an embolus) causing ischemia
• artery may be severed (hemorhagging) causing ischemia
• coronary artery spasm

Question 9

proximal occlusion is more ______ than distal occlusion

Answer 9

severe

Question 10

The extent of the infarct depends on?

Answer 10

• vessel: how much tissue is affected
• duration of occlusion (time)
• complete or partial occlusion
• metabolic needs of affected tissue (sleeping vs exercising)
• existing collateral circulation in area (other vessels in area)
• HR, BP, rhythm
• risk factors present

Question 11

Normal ECG waves

Answer 11

PQRSTU

Question 12

Transmural infarct

Answer 12

• goes across entire thickness of ventricular wall
• proximal occlusion (primary artery obstruction)
• ST elevation (STEMI)

Question 13

subendocardial infarct

Answer 13

• Inner part of ventricular wall
• distal occlusion (branches)
• ST depression (NSTEMI)

Question 14

Typical mnfts of MI

Answer 14

• acute severe chest pain – that radiates typically to left arm, neck & jaw (also other areas such as tips of fingers
• anxiety & tachycardia
• nausea & vomiting (severe pain often comes with vomiting, vomiting center of brain near pain center, nociceptors activate pain center which may then activate vomiting center)

Question 15

what is the primary mnfts of MI

Answer 15

-acute severe chest pain that radiates typically to left arm, neck & jaw

Question 16

Diagnosing an MI

Answer 16

1. ECG (will always be abnormal in case of MI)
2. Serum markers (are released when cardiac muscle dies)
3. Angiogram

Question 17

Diagnosing an MI

Answer 17

1. ECG (will always be abnormal in case of MI)–is basis of diagnoses
2. Serum markers (are released when cardiac muscle dies)
3. Angiogram

Question 18

ECG for diagnosing MI

Answer 18

• ECG will always be abnormal in the cause of MI
• basis of diagnosis
• ST depression or elevation (ST segment is isoelectric point should be flat)
• T inversion
• loss of R wave
• abn Q

Question 19

Serum markers for diagnosing MI

Answer 19

• are released when cardiac muscle dies

- Troponin I

Question 20

Serum markers for diagnosing MI

Answer 20

-are released when cardiac muscle dies
-Troponin I & T, myoglobin, CKmb (creatine kinase–enzyme)
3 sub classes of creatine kinase–CKmb is restricted to heart and want to be measuring for an MI
-troponin peaks @ 3-10 hrs after MI
-CKmb is enzyme released by heart muscle and peaks 4-8 hrs after MI

Question 21

angiogram for diagnosing MI

Answer 21

• releases dye into coronary circuit shows blockages & etc
  a) could be problematic-may have atherosclerosis & knocks off some & creates an embolus
  b) may insert a stent
  c) may ballon “blow up” vessel to create patency