STEMI

Question 1

Definition?

Answer 1

Myocardial cell death occurring due to a prolonged mismatch of perfusion and demand, resulting from a complete atherothrombotic occlusion of a coronary artery.

Question 2

Risk factors?

Answer 2

• Smoking
• Hypertension
• Diabetes
• Obesity
• Metabolic syndrome
• Physical inactivity
• Dyslipidaemia
• Renal insufficiency
• Established CHD
• Family history of CHD
• Cocaine
• Male
Advanced age

Question 3

Differentials?

Answer 3

• Unstable angina
• NSTEMI
• Aortic dissection
• PE
• Pneumothorax
• Pneumonia
• Pericarditis
• Myocarditis
• GORD
• Oesophageal spasm
• Costochondritis
• Anxiety
• SCAD-younger women
• Takotsubo cardiomyopathy

Question 4

Epidemiology?

Answer 4

Age: Younger adults
Sex: Male
Ethnicity: N/A

Question 5

Aetiology?

Answer 5

Irritation or atherosclerosis causes endothelial cell dysfunction

Question 6

Clinical Presentation

Answer 6

• Chest pain-crushing, severe-radiates to left arm, neck, jaw
• Dyspnoea
• Pallor
• Diaphoresis
• Cardiac risk factors
• Dizziness
• Distress
• Palpitations
• N and V

Question 7

Pathophysiology?

Answer 7

• Endothelial cells damaged by toxins become a site for atherosclerosis-fat , calcium, white blood cells, cholesterol and lipids build up
• Plaques sit in blood vessels-smaller caps with soft caps prone to breakage becomes thrombogenic and forms clots as clotting factors adhere here and release chemicals enhancing this process
• This occludes the artery,- can be LAD(anterior), RCA(back), LCX( lateral)
• Myocardial cells become hypoxemic and so begin to die after 20-40 mins and necrosis-affects inner third quicker
• ST elevation-transmural infarct-whole thickness of wall
Has to be treated quickly

Question 8

1st line investigations?

Answer 8

Cardiorespiratory exam and history

Question 9

2nd line investigations?

Answer 9

• ECG-ST elevation and
  
  • ≥2.5 mm in men <40 years old
  • ≥2 mm in men >40 years old
  • ≥1.5 mm in women in V2-V3 and/or ≥1 mm in the other leads
• Cardiac troponin-acute MI is definitively confirmed by a rise and/or fall in cardiac troponin (withat least one value >99th percentile of the upper reference limit) in a patient who has symptoms or signs of ischaemia
• Glucose-Uncontrolled hyperglycaemia in all pts/hypoglycaemia
• FBC-anaemia/raised inflammatory markers
• Electrolytes, urea, creatinine, amd eGFR-K, Ca and Mg cause arrhythmias
• CRP-infection or inflammation
• Serum lipids-RF of hypercholesterolaemia

Question 10

3rd line investigations?

Answer 10

• ABG-supplemental oxygen if
  
  • arterial oxygen saturation (SaO2) <90% or
  • PaO2<60 mmHg
• CXR-
  
  • pulmonary oedema
  • widened mediastinum
  • cardiomegaly
  • permanent pacemaker
  • biventricular pacemaker
  • sternal wires
  • clear lung fields
  • normal cardiac contour
• Transthoracic echo
  
  • left ventricular regional wall motion abnormalities
  • valvular defects
  • right ventricular function
  • pericardial effusion
  • left ventricular mural thrombus
• cMyC-gold standard

Question 11

Management pathway if <12 hrs and PCI?

Answer 11

• Aspirin and P2Y12 inhibitor (clopidogrel)-in IR
• Analgesia-morphine
• Anti-emetic-metoclopromide
• Oxygen-if <90%
• IV nitrate-HT,pain after GTN or CHF
• Parenteral anti-coagulation-by IR team-heparin
• Glycoprotein IB and and IIIa inhibitor-IR team-tirofiban

Question 12

Management pathway if <12 hrs and no PCI?

Answer 12

• Aspirin and P2Y12 inhibitor (clopidogrel)-in catheter lab
• Analgesia-morphine
• Anti-emetic-metoclopromide
• Oxygen-if <90%
• IV nitrate-HT,pain after GTN or CHF
• Angiography after fibrinolysis

Question 13

Management pathway if CI to fibrinolysis?

Answer 13

above and PCI

Question 14

Management pathway if 12-48 and symptomatic?

Answer 14

Assess for PCI

Question 15

Post-op management?

Answer 15

• Beta blocker/CCB
• ACE inhibitor or AngII RA
• Statin
• DAPT
Aldosterone antagonist/lipid-lowering medication

Question 16

Give a list of some complications

Answer 16

• Sinus bradycardia, first-degree heart block
• Type I second-degree heart block
• Complete heart block with anterior/inferior MI
• Recurrent chest painnn
• Type II second-degree heart block with anterior MI
• Acute mitral regurgitation
• VSD
• Acute pericardial tamponade
• Dressler’s syndrome (post-infarction pericarditis)-increase oxygen conversion into reactive oxygen species-inflammation
• CHF
• Ventricular arrhythmias
• Depression
• In-stent thrombosis
• LV thrombus
• LV aneurysm

Question 17

Prognosis?

Answer 17

• Varies form time to presentation and treatment
• Improved if early reperfusion time, adherence to meds and less RF’s
• 70% people survive