Spot ECG Diagnosis: A 76 year old man with a history of CKD presents to the Emergency Department with weakness. You obtain the following ECG. A recent prior ECG showed normal sinus rhythm with no other abnormalities. What is the most likely abnormality that you will find on his bloodwork to explain this ECG?

Answer: Hyperkalemia. Hyperkalemia is defined as a serum potassium level >5.2mmol/L. However, ECG changes usually do not manifest until potassium level >6.0mmol/L. ECG features of hyperkalemia include peaked T waves, P wave widening/flattening, QRS widening with bizarre QRS morphology.