This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Medicine
[{'content': 'A 78-year-old man with advanced renal disease has the ECG shown in Figure below (lead II). What is the diagnosis? \nSelect and explain. \nA. hyperkalemia, B. hypercalcemia, C. hypernatremia, D. pericarditis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: No atrial activity is detected. The ventricular rate is slightly irregular. Beat number 4 is a ventricular premature contraction. The T waves are tall and markedly peaked. This type of T wave is characteristic of hyperkalemia, as is absence of visible atrial activity.The potassium level was 8.2mmol/L.', 'role': 'assistant'}]