CV CPC 2 Acute Coronary Syndrome

Question 1

Contrast the causes of stable and unstable angina

Answer 1

stable angina: cause by insufficient myocardial perfusion due to a stenosed atherosclerotic vessel (reduced with rest)

unstable angina: disruption of an atherosclerotic plaque with partial thrombosis, embolus or vasospasm (systems are progressive and indicative of future MI)

Question 2

Irreversible damage to myocardium (necrosis) usually requires severe ischemia lasting how long?

Answer 2

20-30 min (complete after 6 hours, unless heart is conditioned with intermediate ischemia)

Question 3

Describe how the gross findings of a MI evolve over time?

Answer 3

ill-defined blueish-red area (12-24hrs)
defined yellow tan area (soft)
10 days-14 days area rimmed by vasculized granulation tissue
resolution by formation of scar

Question 4

Which is the most specific biomarker for MI and when would expect the biomarker to be present?

Answer 4

troponins T and I appear 2-4hrs and peak in 24hrs

CK-MB is sensitive but not specific, doesnt last as long as troponins (72hrs vs 7-10days)

patients with re-profused ischemic tissue have metabolite peak early (monitored to judge the severity)

Question 5

When and where are you most likely to see a pre-wall rupture?

Answer 5

3-7 days post MI when necrosis, neutrophil infiltrate and lysis of connective tissue peaks

anterior-lateral wall is most common at mid-ventricular level

Question 6

Sudden cardiac death is usually the result of lethal _____ and usually in the context of ____

Answer 6

lethal arrhythmia in the context of ischemic heart disease (** but not necessarily in the context of MI)