Cardio: Ischemic Heart Disease and MI Flashcards Preview

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Flashcards in Cardio: Ischemic Heart Disease and MI Deck (18):
1

  • Secondary to atherosclerosis; exertional chest pain in classic distribution
  • Usually w/ ST depression on ECG
  • Resolves w/ rest

Stable Angina

2

  • Occurs at rest, secondary to Coranary artery spasm
  • Transient ST elevation
  • A/w tobacco, cocaine, and triptans
  • Treat w/ Ca2+ channel blockers, Nitrates, and Smoking cessation

Variant Angina (Prinzmetal)

3

  • Thrombosis with incomplete coronary artery occlusion
  • ST depression
  • Increasing frequency and intensity of chest pain

Unstable Angina

4

  • Distal to Coronary stenosis, vessels are maximally dilated at baseline
  • Administration of vasodilators (dipyridamole, regadenoson) dilates normal vessels and shunts blood toward well-perfused areas 
    → ↓ flow and ischemia in the poststenotic region
  • Principle behind pharmacologic stress tests

Coronary Steal Syndrome

5

  • Most often Acute Thrombosis due to Coronary Artery Atherosclerosis w/ complete occlusion of Coronary Artery and Myocyte necrosis
  • Cardiac biomarkers are diagnostic
  • Transmural, ECG will show ST elevations
  • Subendocardial, ECG will show ST depression

Myocardial Infarction

6

Evolution of MI: 0 - 4 hr

  • Gross: None
  • Microscope: None
  • Complications:
    • Arrhythmia, HF, Cardiogenic shock, Death

7

Evolution of MI: 4 - 12 hr

  • Gross:
    • Occluded artery → Dark mottling w/ tetrazolium stain
  • Microscope:
    • Early coagulative necrosis, release of necrotic cell contents into blood; edema, hemorrhage, wavy fibers
  • Complications:
    • Arrhythmia, HF, Cardiogenic shock, Death

8

Evolution of MI: 12 - 24 hr

  • Gross: Occluded Coronary Artery

  • Microscope:

    • Neutrophil migration starts

    • Reperfusion injury may cause contraction bands due to free radical damage

  • Complications:

    • Arrhythmia, HF, Cardiogenic shock, Death

9

Evolution of MI: 1 - 3 days

  • Gross: Hyperemia
  • Microscope:
    • Extensive Coagulative necrosis
    • Tissue surrounding infarct shows acute inflammation w/ Neutrophils
  • Complications: Fibrinous pericarditis

10

Evolution of MI: 3 - 14 days

  • Gross:
    • Hyperemic border; central yellow-brown softening - maximally yellow and soft by 10 days
  • Microscope:
    • Macrophages, then granulation tissue at margins
  • Compications:
    • Free wall rupture → tamponade; papillary muscle rupture → Mitral regurgitation; interventricular septal rupture due to macrophage-mediated structural degradation
    • LV Pseudoaneurysm (Mural thrombus "plugs" hole in myocardium → "time bomb"

 

11

Evolution of MI: 2 weeks to several months

  • Gross: Recanalized artery w/ Gray-white scarring
  • Microscope: Contracted scar complete
  • Complications:
    • Dressler syndrome, HF, Arrhythmias, True ventricular aneurysm (outward bulge during contraction), "Dyskinesia"

12

Cardiac Troponin I

  • Rises after 4 hrs and is ↑ for 7 - 10 days
  • More specific than other protein markers

13

CK-MB

  • Predominantly found in myocardium but can also be released by skeletal muscle
  • Useful in diagnosing Reinfarction following Acute MI because levels return to normal after 48 hrs

14

Q waves: V1 - V4

Anterior wall infarct - LAD 

15

Q waves: V1 - V2

Anteroseptal infarct - LAD

16

Q waves: V4 - V6

Anterolateral infarct - LAD or LCX

17

Q waves: Lead I, aVL

Lateral wall infact - LCX

18

Q waves: Lead II, III, aVF

Inferior wall infarct - RCA