MI

Question 1

Most commonly blocked arteries

Answer 1

Left Anterior Descending Artery - Septal - V1 -V2
Right coronary artery - Anterior v3-V4 and Inferior II, III, aVF
Left circumflex artery - Lateral V5-V6, I, aVL

Question 2

Blockage progression xones

Answer 2

Zone of perfusion - blockage - ischaemia- Zone of necrosis (20-40mins), Zone of necrosis extension (3-6hrs)

Question 3

MI types

Answer 3

Endocardial/Subendocardial infarct- NSTEMI

Transmural Infarct - STEMI

Question 4

Investigations

Answer 4

ECG
Lab Enzymes -
Troponin I & T >2-4hrs,pk 48hrs, elevated 10-14days
CK - MB >2-4hrs, pk 24hrs, last 48-72hrs. non specific as can refer to skeletal muscle injury. useful in diagnosis of reinfarction

Question 5

Symptoms of mI

Answer 5

Crushing chest pain - radiating to arm, jaw
Diaphoresis
Nausea
Vomiting
Fatigue
Dyspnoea

Question 6

MI complications

Answer 6

Arrhythmias (1-3dys)
Cardiogenic shock
Hear failure
Pericarditis (1-3dys) ---- Dressler's syndrome (2-10wks)
Risk of rupture (3-14dys) - Tamponade

Question 7

MI healing

Answer 7

1-3 dys - Neutophils and necrosis
3-14 dys Granulation tissue
4-6wks Complete scar

Question 8

MI treatment / therapy

Answer 8

Medication - Fibrinolytic therapy
Antiplatelets, Anticoagulants, Nitrates, Beta Blockers, Pain meds, Statins
Angioplasty
PCI - Percutaneous Coronary interventions

Question 9

Reperfusion Injury

Answer 9

ischemia-reperfusion injury (IRI) or reoxygenation injury, is the tissue damage caused when blood supply returns to tissue (re- + perfusion) after a period of ischemia or lack of oxygen (anoxia or hypoxia)