Injury, Ischemia, and Infarction patterns Basic EKG interpretation

-ST Elevations -ST Depressions -T wave inversions -Non specific ST-T changes -Q waves

ST Elevations

Definition ●New ST-segment elevation at the J-point in two contiguous leads with the cut-points: ≥0.1 mV (1 mm) in all leads other than leads V2-V3;

Definition ●New ST-segment elevation at the J-point in two contiguous leads with the cut-points: ≥0.1 mV (1 mm) in all leads other than leads V2-V3; ●For leads V2-V3: ≥2 mm in men ≥40 years; ≥2.5 mm in men <40 years, or ≥1.5 mm in women regardless of age.

STEMI imitators -Pericarditis -Prinzmetel’s Angina -Early repolarization -Left Ventricular Hypertrophy -LBBB -Ventricular aneurysm -Ventricular paced -Increased intracranial pressure -Brugada syndrome

ST depression criteria -New horizontal or downsloping ST depression >= 0.5 mm in two contiguous leads -Deeper ST depressions indicate higher likelihood of ACS and worse prognosis

T wave inversions -Inversions deeper than 1 mm in two contiguous leads

Nonspecific ST-T changes -ST-T changes that don’t meet above criteria

Differential diagnosis for Nonspecific ST-T changes -Physiologic variant -Electrolyte abnormalities -Fever -Acidosis/Alkalosis -Endogenous catecholamines -Drugs -Acute abdominal process -Metabolic changes -CVA -Myocarditis -Pericarditis -Pulmonary emboli -Myocardial ischemia -Pulmonary processes

Pathologic Q waves 40 ms (1mm) in duration At least 1 mm deep Greater than 25% of entire QRS amplitude Two contiguous leads