Non-Myocardial Infarction Causes of ST Changes on ECG

Cardiac Causes

• The European Society of Cardiology recommends that both dilated and hypertrophic cardiomyopathy can produce ST-segment and T-wave abnormalities 1, 2
• Takotsubo (apical ballooning) cardiomyopathy causes ST elevation mimicking anterior STEMI, according to the American Heart Association 3, 4
• Left ventricular hypertrophy produces secondary repolarization abnormalities with ST-segment changes, as stated by the European Society of Cardiology 1
• Patients with left ventricular hypertrophy and ST changes represent the highest risk group for adverse outcomes, even higher than those with primary ST deviation, according to the American College of Cardiology 3, 4

Conduction Abnormalities

• The American Heart Association states that both right and left bundle branch block cause secondary ST-T wave abnormalities due to altered depolarization sequence 3, 4, 5
• Patients with bundle branch block and chest pain are at highest risk for adverse outcomes, as recommended by the American College of Cardiology 3, 4

Normal Variants

• The American Heart Association describes the early repolarization pattern as widespread ST-segment elevation at the J point with QRS slurring or notching 3, 4, 5
• The early repolarization pattern is more common in young Black males, according to the American College of Cardiology 3, 4

Electrolyte Abnormalities

• The American Heart Association states that hyperkalemia produces prominent J point elevation with peaked T waves and QRS widening 5
• Hypocalcemia and other electrolyte disturbances can affect repolarization and cause primary ST-T wave changes, as recommended by the European Society of Cardiology 5

Drug and Toxin Effects

• The American College of Cardiology states that digitalis causes characteristic "scoop" or "soup ladle" ST-segment depression 5
• Tricyclic antidepressants cause deep T-wave inversion, according to the American Heart Association 3, 4

Non-Cardiac Causes

• The European Society of Cardiology states that pulmonary embolism can produce T-wave inversions and right ventricular strain pattern 1, 2, 7
• Hypothermia produces Osborn waves (prominent J point elevation) mimicking ST elevation, as described by the American Heart Association 5

Critical Diagnostic Approach

• The American College of Cardiology recommends always comparing with prior ECGs when available, particularly in patients with left ventricular hypertrophy or previous MI 1, 2
• The American Heart Association states that bundle branch block, paced rhythm, or left ventricular hypertrophy with chest pain represent highest mortality risk, requiring immediate troponin measurement and aggressive evaluation despite ECG ambiguity 3, 4