ACS

Coronary Artery Disease

Can be chronic (chronic coronary syndrome) or acute (acute coronary syndrome)

PATHO

Type 1 MI

  • Atherosclerotic plaque rupture/acute coronary thrombosis ➔ ischemia ➔ infarct

Type 2 MI

  • Myocardial O2 supply & demand mismatch ➔ ischemia ➔ infarct

  • Ischemia: ↓ blood supply means ↓ O2

  • Infarct: tissue necrosis

  • Type 2 MI can come from anything that causes ↓ O2 supply

    • occlusion of coronary arteries (vasospasm)

    • ↓ supply: ↓ perfusion (hypotension/brady, anemia)

    • ↑ demand: Heart working hard (tachy)

SSX

  • Retrosternal chest pain/tightness

    • Dyspnea

    • Diaphoresis

    • Dizzy/light-headed

    • Syncope

    • Belching/nausea/indigestion

  • Women, elderly, DM pts are more likely to present with atypical sx

  • Bradycardia in inferior MI

  • DM ➔ ↑ platelet reactivity ➔ ↑ risk of developing ACS

  • Acute MI with DM ➔ ↑ mortality and future cardiac events

  • RCA supplies conduction system

DX

  • Chest pain: EKG within 10 mins

  • Cardiac biomarkers

    • Cardiac troponin (cTn) I/T - (Early presentation may not be detectable ➔ remeasure 3-6hrs)

    • CK/CK-MB

    • Myoglobin (earliest)

  • Myoglobin (first)

    • Detected in ~ 1hr, peaks ~ 6hr, levels off ~ 1 day

  • CK-MB - More specific to cardiac muscle

    • Detected in ~6hrs

    • Peaks ~ 1 day, levels off ~ 3 days

  • Troponin (lasts the longest)

    • Rapid may detect within 2-3hrs (Early presentation may not be detectable ➔ remeasure 3-6hrs)

    • Peaks ~1 day, levels off ~1 week

TX

  • Someone says chest pain:

    • EKG (within 10 min)

      • Have you used any medications for erectile dysfunction in the last 24hrs?

      • Have you used any cocaine?

      • Are you allergic to anything?

    • Get blood pressure before giving NTG (probably best avoided if inferior MI)

    • Give chewable 325mg (really 324mg) ASA

    • β-blockers (if no signs of HF, brady, cocaine use, vasospastic angina hx)

    • Start statin

    • Morphine if still complaining about unacceptable pain

    • Anti-platelets: ticagrelor, clopidogrel

    • Anticoagulants: UF heparin

  • Unstable angina (negative cardiac labs) or NSTEMI (positive cardiac labs) ➔ risk stratification (TIMI/HEART)

      • To determine whether/when to cath & reperfuse

  • STEMI ➔ cath lab for reperfusion PCI (percutaneous coronary intervention)

    • Door to PCI < 90 mins, if delay going to be > 120 mins ➔ fibrinolytics

      • (door to fibrinolytics 30 mins)

Post MI complications

Post MI day 1

  • Fatal arrhythmia (vtach, blocks, a-fib) or ↓ contractility

1-3 days post MI

  • Fibrinous pericarditis

3-14 days post MI

  • Papillary muscle rupture ➔ mitral regurgitation

    • MC in PAD occlusion

  • Ventricular wall rupture (➔ pericardial effusion) or septal wall rupture (➔ left ➔ right shunting ➔ right sided HF)

    • MC in LAD occlusion

2wks-months post MI

  • Atrial and ventricle aneurysms can ➔ arrhythmias & thrombus or rupture

  • Post MI (Dressler) syndrome ➔ acute pericarditis (diffuse, concave ST elevation)

Anytime

  • Ischemic cardiomyopathy ➔ CHF

  • Another MI

Vasospastic Angina (prinzmetal)

PATHO

  • Not ACS but tx like any other CP til proven otherwise

  • Cigarette smoking is major RF (RF for cardiac chest pain do not apply to vasospastic)

  • Coronary smooth muscle hyper activity ➔ spasm ➔ angina

    • If continued spasm occurs can ➔ ischemia/infarct

    • Can occur it pts with normal or atherosclerotic

SSX

  • Non-exertional chest pain, can be brought on with hyperventilation

  • Younger pts, associated with Raynaud syndrome, early morning

DX

    • EKG will show transient depression or elevation only during sx or when provoked (acetylcholine, ergonovine)

TX

    • CCB ± NTG

    • β-blockers contraindicated

  • Cocaine use can ➔ vasospasm ➔ ischemic changes on EKG

    • Prolonged use ➔ prolonged constriction ➔ infarct on EKG