This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Pulseless electric activity due to ? 
Select and explain. 
A. Ionic abnormality, B. Alkalosis, C. Hyponatremia, D. All of the above
A: Ionic abnormality
Answer: A: Ionic abnormality 
Explanation: Answer- A. Ionic abnormality Pulseless electrical activity or PEA (also known as by the older term electromechanical association) refers to a clinical diagnosis of cardiac arrest in which hea rhythm is observed on the electrocardiogram that should be producing a pulse but is not.