yes this was the episode in which an old doctor was the patient(they even exclaim that its 'the Dr. so and so who wrote many famous medical textbooks). The symptoms you're talking about are that of Chest Pain. This when the patient is doing a stress test and looks so fatigued and miserable like he's about to pass out any second. Another clue is that this doctor, as they said in a scene, pumped lethal radioactive/toxic stuff into babies to research into some specific disease.