Review Question - QID 109862

This patient with large peaked T waves most likely has hyperkalemia, which is consistent with the etiology of acute kidney failure.

The T wave on an EKG represents ventricular repolarization from both ventricles. The major changes that can occur with regards to this wave are peaked, flattened, and inverted waves. Inversion indicates recent myocardial infarction among other conditions. Flattened T waves are indicative of hypokalemia. Tall peaked T-waves are an early sign of hyperkalemia. Hyperkalemia leading to peaked T waves are most commonly caused by kidney failure; however, they can also result from other causes such as potassium-sparing diuretics or adrenal failure.

Figure A shows an EKG with the characteristic finding of tall peaked T waves consistent with hyperkalemia.

Incorrect Answers:
Answer 2: Bundle branch conduction changes can be seen on an EKG as RSR' sequences sometimes known as bunny ears; however, this would not present with peaked T waves.

Answer 3: Excessive use of thiazides may lead to hypokalemia, which can be seen on an EKG as flattened T waves, not peaked T waves.

Answer 4: Failure of atrioventricular node conduction results in heart block and can be seen on an EKG as widened PR intervals or dropped QRS waves; however, this would not present with peaked T waves.

Answer 5: Interruption of pulmonary perfusion through a pulmonary embolism can be seen on EKG as an SI QIII TIII pattern; however, this pattern is not always present and would not include peaked T waves.

Bullet Summary:
Peaked T waves are associated with hyperkalemia, which can be seen in cases of kidney failure, potassium-sparing drugs, or adrenal failure.