Scenario: This 12-lead electrocardiogram (ECG) was obtained from a 53-year-old man on a Monday morning at an outpatient surgery center as part of a preoperative assessment for an esophagogastoduodenoscopy and colonoscopy. This was part of an evaluation for a kidney transplant due to end-stage renal failure. Other history includes hypertension, diabetes, and hypercholesteremia. His dialysis was scheduled for 3 times per week (Monday, Tuesday, and Fridays), however, he missed his Friday appointment. He complained of muscle weakness and tiredness, but all other vital signs were within normal range.
Normal sinus rhythm with early repolarization pattern (verified from prior ECGs) and peaked, tentlike T waves suggestive of hyperkalemia. Early repolarization can manifest as atypical nonischemic ST-segment elevation indicated by the “fishhook” pattern.
Because this patient had not had dialysis for 6 days, complained of muscle weakness, and displayed tentlike T waves, potassium level was measured urgently and was 8.2 mmol/L...