Final answer:
Tall peaked T-waves, flat P-waves, prolonged PR intervals, and widened QRS complexes are indicative of Hyperkalemia, a condition characterized by elevated levels of potassium in the blood that can significantly affect cardiac function.
Step-by-step explanation:
The condition in which tall peaked T-waves, flat P-waves, prolonged PR intervals, and widened QRS complexes can present is Hyperkalemia. These specific electrocardiogram (ECG) changes are indicative of elevated levels of potassium in the blood. In ECG interpretations, different wave patterns can suggest various cardiac conditions. A small P wave normally represents atrial depolarization, while the large QRS complex represents ventricular depolarization, and the T wave reflects ventricular repolarization. Hyperkalemia can alter these waveforms in the ways described, which can be life-threatening if not promptly treated.