This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ECG and Arrhythmia 2, Subject name: Medicine
[{'content': 'Which of the following is not a cause of PEA (Pulseless Electrical Activity)? \nSelect and explain. \nA. Low pO2 < 60mm Hg, B. Hydrogen ion depletion, C. Hypokalemia, D. Hypovolemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The 5 H and 5 T of pulseless electrical activity - PEA implies that electrical activity is seen on ECG but the pulse is absent. The leading cause of PEA is hypoxia secondary to respiratory failure (40-50% cases) and hypovolemia. Hydrogen ion depletion implies alkalosis whereas PEA occurs with acidosis. H Hypovolemia Hypoxia Hydrogen Ion (acidosis) Hypo / Hyperkalemia Hypothermia T Toxins Tamponade Tension Pneumothorax Thrombosis (hea: acute, massive MI) Thrombosis (lungs: massive PEE)', 'role': 'assistant'}]