Ischemic Heart Disease (Exam 2)

Question 1

Define myocardial ischemia and is it reversible?

Answer 1

a condition of myocardial oxygen deficit: demand > supply. Due to decreased coronary artery perfusion. Usually reversible

Question 2

Define myocardial injury and is it reversible?

Answer 2

occurs with ongoing ischemia. may be reversible or go on to infarction.

Question 3

Define myocardial infarction and is it reversible?

Answer 3

progression of ischemia to irreversible cell death. causes permanent impairment of electrical activity and contraction. not reversible.

Question 4

Identify the 3 main anatomic locations in the heart where acute MIs occur and list the coronary arteries that supply these areas.

Answer 4

Inferior infarct (diaphragmatic area): right coronary artery
Lateral wall infarct (left lateral wall of the heart): left circumflex artery
anterior infarct (anterior surface of left ventricle): left anterior descending artery.

Question 5

what are the measurement characteristics of an abnormally elevated or depressed ST segment?

Answer 5

must be more than 1 mm (1 box) above or below the baseline.

Question 6

During an acute MI how does the EKG evolve in regards to the t wave?

Answer 6

T wave peaking followed by t wave inversion

Question 7

During an acute MI how does the EKG evolve in regards to the ST segment?

Answer 7

ST segment elevation (1 box or higher). happens during the change from ischemia to infarction and damage still usually reversible at this point.

Question 8

During an acute MI how does the EKG evolve in regards to the Q wave?

Answer 8

Appearance of new q waves that are greater than .04 seconds in duration and > 1/3 the height of the QRS complex. these are usually seen several hours after the infarction and not reversible. can last for years and even life of patient.

Question 9

What is the primary cause of ischemic heart disease?

Answer 9

atherosclerotic obstruction of coronary arteries

Question 10

What is the artery that is involved in an anterior MI?

Answer 10

Left anterior descending artery

Question 11

What is the artery that is involved in a lateral MI?

Answer 11

Left circumflex artery

Question 12

What is the artery that is involved in an inferior MI?

Answer 12

90% Right coronary

10% Left circumflex

Question 13

What EKG changes will you see in reversible ischemia?

Answer 13

ST depression-usually horizontal or down sloping (significant if >/= to 1 mm).
T wave flattening or inversions
Changes typically resolve.

Question 14

What EKG changes will you see in complete infarction?

Answer 14

• ST elevation
• variable T wave changes
• initial changes typicaly followed later by Q waves (q waves are permanent and represent electrically dead area of muscle)
• New BBB
• Reciprocal EKG changes

Question 15

Define reciprocal EKG changes.

Answer 15

mirror-image ST-T changes (usually ST depressions) in leads distant from the primary ST elevation.

Question 16

Discuss the characteristics of pain encountered in an acute MI according to location and radiation.

Answer 16

location: substernal or left-sided
radiation: to neck, jaw, shoulders, left or both arms

Question 17

Discuss the characteristics of pain encountered in an acute MI according to quality.

Answer 17

heaviness, pressure, tightness, squeezing

Question 18

Discuss the characteristics of pain encountered in an acute MI according to relation to body movement.

Answer 18

usually unaffected by position change, body movement, deep breath

Question 19

Discuss the characteristics of pain encountered in an acute MI according to associated emotional and physchological manifestations.

Answer 19

often brought on by physical exertion, emotional stress

Question 20

Discuss the characteristics of pain encountered in an acute MI according to responsiveness to rest and/or NTG.

Answer 20

relieved by rest and/or NTG

Question 21

Discuss the importance of the clinical evaluation in diagnosis of an acute MI.

Answer 21

History is the single most important tool of chest pain evaluation.

Question 22

What should you ask about during your history if IHD is suspected?

Answer 22

Chest pain, associated symptoms, risk factors

Question 23

What is the most important lab test to identify IHD and what is something you should keep in mind when evaluating it?

Answer 23

EKG, only 50% of acute MIs initially have classic ST evaluation. even a completely normal EKG doesn’t EXCLUDE acute MI. Must use EKG in conjuction with history, physical, and cardiac enzymes.

Question 24

What is the importance of taking cardiac enzymes for diagnosis of IHD?

Answer 24

Early levels may be normal in acute MI.
Must follow serial enzymes to rule out MI.
Elevated cardiac enzymes ultimately confirm diagnosis of acute MI, but can’t rely on them early.
Normal serial enzymes rule out acute MI, but do not rule out possibility of underlyingischemic heart disease.

Question 25

name the potential complications of acute MIs.

Answer 25

• dysrhythmia
• LV pump failure/cardiogenic shock
• papillary muscle insufficiency
• ventricular septal rupture
• cardiac rupture
• thromboembolism
• pericarditis
• ventricular aneurysm
• right ventricular infarction

Question 26

what is the classic ECG evolution in MI?

Answer 26

• hyperacute T-waves
• giant R waves
• ST elevations
• Q waves

Question 27

What steps/diagnostic tools should you use to diagnose IHD.

Answer 27

• History
• Physical exam
• ECG
• Cardiac Enzymes
• Chest xray
• echocardiogram
• radionuclide scan
• coronary angiogram

Question 28

What symptoms are associated with an acute MI

Answer 28

SOB, diaphoresis, nausea/vomiting, palpitations, dizzy/lightheadedness

Question 29

Why are diabetics in a special category when it comes to ischemic HD and MIs?

Answer 29

• Extensive comorbidites
• Often present asymptomatic or with very generalized concerns such as weakness
• Considered a micro vessel disease