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: Physiology
[{'content': 'Delayed afterdepolarization implies? \nSelect and explain. \nA. Increased intracellular Ca", B. Excessive catecholamines, C. Digitalis toxicity, D. All of the above', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., All of the aboveDelayed afterdepolarizations occur in late phase 3 or early phase 4 when the action potential is nearly of fully repolarized.The mechanism is poorly understood; however, this type of arrhythmia is found to be associated with high intracellular Ca++ concentrations as occurs with digitalis toxicity or excessive catecholamine stimulation.The triggered impulse can lead to a series of rapid depolarizations (i.e. a tachyarrhythmia).", 'role': 'assistant'}]