12-Lead Electrocardiographya comprehensive course

Adam Thompson, EMT-P, A.S.

STE-Mimics

Part 4

Acute Pericarditis

• Inflammation of the pericardium (pericardial sac).

• May present with global STE• STE may appear pronounced due to PR-

depression. • Tip - STE will be present in reciprocal leads• aVR will present with ST-depression

Acute Pericarditis

• Stage Ieverything is UP – ST elevation in almost all leads

• Stage IITransition – "pseudonormalization"

• Stage IIIEverything is DOWN – inverted T waves

• Stage IV Normalization.

Acute Pericarditis

Stage 1 Stage 2 Stage 3

Acute Pericarditis

Acute Pericarditis

Acute Pericarditis

Hyperkalemia

• Peaked, usually narrow, symmetrical T waves

• Severe hyperkalemia may present with straight line from tip of S wave (nadir) to peak of T wave, AKA Sine wave.

• Sometimes presents with wide complexes, possibly lacking P waves. Z-Fold pattern is common with severe hyperkalemia.

• Use medical history to help determine cause.

Hyperkalemia

• Hyperkalemia = High Potassium Level– Peaked T-Waves

• May mimic an acute MI

– Sine Waves• Sign of lethally high potassium level

Sine Wave

Peaked T-Wave

Hyperkalemia

Hyperkalemia

Hyperkalemia

Hyperkalemia

Osborn Waves

• Sometimes called “J-Waves”• Indicates HYPOTHERMIA• May be associated with bradycardia• Extra wave at the J-Point of the QRS-

complex.

Osborn Waves

STE-Mimics

• Take a big look at the entire clinical picture.

• Often, a pathology has not read up on what it is suppose to look like on an ECG, and breaks all the rules.

END

• Up next Ischemia, Injury, & Infarct