We decided, spur of the moment, to take the limited express.
When I had my checkup, they found something unusual in my EKG, so I have to go back for a complete physical at a university hospital in Osaka via the limited express train on Monday.
I already got an express ticket for you, so if you leave now you can still catch the 3:50 express train.
Something that's special and in a hurry must be special indeed. This refers to limited express trains in Japan. They go fast, they stop at fewer stops (because they're special!) and they hurry. Look out for these if you want to get somewhere in a jiffy.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. Just note that the とく goes to とっ.