TIA or heart attack or what?

[BoGus2]

I have an almost 6 year old neutered male registered ragdoll cat, Gus, who's been healthy, tho a little heavy at 16 lbs-- (he is a very big cat in height and all around).  He has a stage 2 (?) heart murmur that I have checked by ultrasound every year and it hasn't gotten worse.  He is overweight compared to his littermate brother, Bo, who tends to be thinner naturally and weighs about 13-14lbs.  Gus is the chubby one....  
Friday night about 10:30, Gus used the litterbox and then right after he left, instead of covering his waste, he started walking off...or hobbling.  His right leg was curled up under him and he tried to straighten it to walk but it wouldn't stretch out.  He didn't cry or make any noise.  He hobbled about 10 steps and then just laid down very quietly.  I went to him right away and checked his leg- no pain, strain or stiffness.  I petted him and talked to him.  He was unresponsive.  Then he stretched both legs out in front like he would if he were stretching except that the legs were bent down at the first joint, tho he didn't arch his back and his legs were soft, not stiff.  He just laid there.  Bo immediately went to his head and cried to him and laid there with him like he knew there was trouble.  When he didn't move, I picked Gus up and held him on my lap gently because I thought he was gone or dying.  I couldn't feel a heart beat or see breathing so if he was, it was shallow.  He doesn't like to be held so I was tentative about even picking him up because I didn't want to cause him anxiety...Anyway, he was on my lap for maybe a minute or two and he lifted his head, got up slowly and walked about 4 steps away, laid down and then waited maybe a minute before he walked away.  
I called the emergency vet and they said he should be seen but to watch him carefully for the next few hours.  I stayed up with him and watched him and he hasn't changed or had any other symptoms.  After a half hour or so, we actually all played (our evening routine) and he was more than fine.  He seems especially lively the past few days.  I am taking him to the vet tomorrow to have him checked just to be sure.
Can anyone tell me what questions I should ask?  
I have worked in the medical industry for years so I know some things about human health but not much about feline health.  
Oh, I don't know if this means anything but I have noticed that Gus blinks a lot...could he be having some mini-strokes?  What tests would be done if the need to check that?  Or is it more likely to be heart or seizures?  I have read online that seizures in cats are rare....Is this a result of the heart murmur?
He is an inside cat-- never gone outside.  I don't have poisonous plants and clean with safe products.  I leave no people food on the counters or in the sink and feed them prescription food because Bo gets crystals in his urine.  Have I left anything out?
As you can tell, I am pretty clueless about this....suggestions or help?  I'm 58 and a first-time owner!  So I don't have history to draw on...  
I'll try to be more succinct next time....!  I didn't know how to say this with less detail!

[heart2heart2]

Hi, I am no expert either. However I volunteer with the cats in an animal shelter and last year we had a cat with similar symptoms that you described. It was thought the cat had a TIA - from a possible thrown blood clot from his heart. He did recover and was adopted, I don't know any more than that. I thought I read somewhere that cats can recover from minor strokes better than people. In any case, it's probably wise to have your kitty checked out. But if the TIA passed they might find anything. I don't know if they treat cats with blood thinners??  I hope your cat is better.

[Savas]

You seem to have a pretty good fix on it. Just describe the event exactly how you did here, down to the detail. I don't want to throw out suggestions as with a vet visit tomorrow, they'll tell you what should be done test wise in what order.

The one thing I'll mention is most vet's assume people have a cap of about a few hundred dollars they're willing to spend and treat with that in mind. If this isn't an issue, make it clear from the start that money is no object (but...don't test recklessly, of course!!!)
I'd also consider picking up pet insurance if you don't have it. It's a big help.