This ECG is from a female patient who presented with weakness. Her labs revealed digitalis toxicity and hyperkalemia. Actual lab values not available. With digitalis toxicity, hypokalemia and hyperkalemia are possible. In severe hyperkalemia, the "tall peaked T waves" can become much shorter, as the QRS and T waves widen. The p waves disappear, and soon the ECG resembles a "sine" wave. This is a very serious emergency!