Some STE-mimics

Pericarditis
[Narrow complex STE-mimic]

ECG signs:

1. Stage I: Diffuse ST elevation (CONCAVE shape!) in all leads except aVR, V1; PR depression (very sensitive indicator)
2. Stage II: ST segments temporarily normalize
3. Stage III: Diffuse ST depression +/- T inversion
4. Stage IV: Gradual normalization of ST and T Waves

Clinical signs:

• Pericardial friction rub
• Central chest pain worsen on inspiration and lying flat, relief by sitting forward
• Raised troponin level, and maybe other cardiac enzyme (so cardiac enzymes [CE] elevation doesn't only indicate MI!)

Some complications:

• Pericardial effusion
• Cardiac tamponade

Hyperkalemia
[Wide complex STE-mimic]

# NB! Potassium is important for repolarization of muscles. Increased potassium cause and FAST and ABNORMAL repolarization

Some possible causes:

• Renal failure
• Metabolic acidosis
• Addison's disease (Hypoaldosteronism)
• Potassium sparring diuretics: Spironolactone (aldosterone antagonist), Hydrochlorothiazide (HCTZ)
• etc

ECG signs:

• Widen QRS, in severe case can observe slurred QRS (slow depolarization due to increased positive charge on outer membrane)
• Shorten QT (due to fast repolarization)
• Hyperacute, tall and peak, tent-shape T wave (due to abnormal repolarization)
• ST elevation
• Widen PR (>0.2s) in severe case (due to atrial paralysis)
• Ventricular arrhythmia, ventricular tachucardia, VF occurs in very sever case. When potassium level high enough, it greatly reduce resting membrane potential (RMP) and myocardium eventually become inexicitable and heart stops in diastole x.x
  

Other clinical signs in hyperkalemia:

• Hyporeflexia, paralysis, constipation
• Neuroloical and muscular symptoms
• Death may occurs before and other clinical signs x.x

Word of Caution:
Nothing is absolute in medicine, patient with aortic dissection might have ECG signs of pericarditis. So remember,

Smirnov : "In medicine everything is possible!"