Neonatal Nurse Practitioner Practice Exam 2025 – Complete Prep Resource

Peaked T waves are a well-recognized ECG change associated with hyperkalemia. As potassium levels rise, the electrical properties of cardiac cells are altered, leading to characteristic changes in the heart's electrical activity. Specifically, peaked T waves represent an elevation and distortion of cardiac repolarization due to increased extracellular potassium concentration. This change can be a critical indicator that helps in the diagnosis of hyperkalemia.

In contrast, the other manifestations do not typically occur with hyperkalemia. Atrial tachycardia may not specifically relate to elevated potassium levels and can occur in various cardiac conditions. A narrowed QRS complex one would generally expect in conditions like hypercalcemia or certain types of heart block, rather than hyperkalemia. Bradycardia can occur due to various factors, including medications or intrinsic conduction system issues, but is not a sole clinical manifestation of hyperkalemia.

Therefore, the presence of peaked T waves is specifically indicative of hyperkalemia and serves as an essential finding in the identification and management of this electrolyte disturbance.