ECG tutorial: Myocardial ischemia & infarction

Question 1

In patients with myocardial ischemia or infarction, ECG findings are influenced by multiple factors, including:

Answer 1

• Duration = hyperacute/acute vs evolving/chronic
• Size = amount of myocardium affected
• Anatomic location = anterior, lateral, or inferior-posterior
• Baseline (prior) ECG abnormalities.

Question 2

ECG evidence of ischemia refers to

Answer 2

abnormalitis (or changes) that are reversible once ischemia of the myocardium is no longer present.

Question 3

ECG evidence of infarction refers to

Answer 3

abnormalitis that are likely permanent & represent myocardial tissue that has been infarcted.

Question 4

Myocardial ischemia precedes acute MI in all patients but not all patients with myocardial ischemia develop MI?

True or False

Answer 4

True

Question 5

T wave inversions are defined as

Answer 5

> or equal to 1mm in depth in 2 contiguous leads.

Question 6

ST segment depression is defined by

Answer 6

a horizontal or down-sloping ST segment that is depressed ≥ 0.5 mm at the J-point in ≥ 2 contiguous leads.

Question 7

ST segment elevation defintion