See description and answer below

Hint: this is a dialysis patient

1. There are peaked T-waves

2. There is a long ST segment, resulting in a long QTc (490 ms).  See the ST segments in inferior and lateral leads especially.

Diagnosis: hyperkalemia (6.0 mEq/L) + hypocalcemia (causing long ST segment)  (ionized Ca = 3.41 mEq/L)

Here is the patient’s ECG when the K = 4.1 and the Calcium is also low:

ST segments and QT are long (hypocalcemia), but the T-waves are not peaked.