Myocardial Infarction Flashcards
1
Q
What is MI
A
- prolonged ischemia, injury and death of an area of the myocardium caused by occlusion of one or more of the coronary arteries
2
Q
precipitating factors of MI
A
- atherosclerotic heart disease with thrombus formation
- coronary vasospasm
- embolism
- cocaine
3
Q
What is a zone of infarction
A
- consists of necrotic, noncontractile tissue
- electrically inert
- on ECG: ST segment deviation > 1mm
4
Q
Zone of injury
A
- area immediately adjacent to central zone
- tissue is non contractile
- cells under going metabolic changes
- electrically unstable
- On ECG: see elevated ST segments in leads of injured area
5
Q
Zone of ischemia
A
- outer area
- cells also undergoing metabolic changes
- electrically unstable
- on ECG: T wave inversion
6
Q
Transmural infarction site
A
- full thickness of myocardium
- often ST elevated MI - STEMI
7
Q
Nontransmural infarction site
A
- subendocardial, subepicardial, intramural infarctions
- non-ST elevated MI - NSTEMI
8
Q
Right coronary artery occlusion
A
- inferior MI
- right ventricle infarction
- disturbances of upper conduction system
9
Q
Circumflex artery occlusion
A
lateral MI
ventricular ectopy
10
Q
left anterior descending artery occlusion
A
anterior MI
disturbances of lower conduction system
11
Q
Impaired ventricular function results in
A
- decreased stroke volume, CO, and EF
- increased end diastolic ventricular pressures
12
Q
electrical instability
A
- arrhythmias
- present in injury and ischemic areas
13
Q
What is sudden death usually due to
A
significant ischemia or ventricular arrhythmia
14
Q
A
