Yes, if your goal is to finish ... alive.... which I think it is. Do your practice swim. Let the pack get started and swim without the stress of 100 plus other people trying to swim over you and have fun with it.

2.5 hours maybe.

Are we to assume because of the heart surgery that you are old? Overweight? Un-athletic?
Really, how could we possibly answer this question anonymously as it were? You tell us nothing about yourself.

Anyway, if your Docs say you can, then you can.

Pace yourself.
These short, short tris are meant to be a flat-out sprint for the competitive bunch, but when the dust clears in their wake (to mix my metaphors) you can sensibly follow behind at your own pace, get the notch on your belt. Keep training. Move on to the next challenge.

Live long and prosper,

PoC

Those would be fair assumptions. I was not out of shape and have been athletic for the vast majority of my 36 years of life. Ran x-country in high school, played basketball and lacrosse in high school and lacrosse in college; I also played post collegiate lacrosse and have run in more races than I can count, including 3 marathons and have competed in several bike races as well. Heart surgery was to repair a jacked up mitral valve that was regurgitating blood into my lungs.

I can live with 2.5 hours to complete the tri. Thanks for the info.

Useful info. Thanks. Add it to your profile so we can get to know you. :)

Matt may be right about your finishing faster, just don't stress yourself. We want this to be your first tri, not your last. Pace is everything.

and yeah, you could probably be ready to do it in about 2.5hrs from now. It really is a modest training effort when done at your own pace.

The winner will take about an hour to complete it, but forget him.

PoC

I'd say go for it -- as long as you are comfortable in the water. Reading that you are working on your swim and being less anchor-like leads me to believe you have been in the water, and able to relax, take it easy, and complete the distance. So do that -- enjoy the swim, making sure you start at the back if you are slower (so that you don't have to be swam over and bumped and punched as much) and then get on that bike and run and enjoy your first tri finish :)

Okay, by stating 'responsible' you are implying by running said tri, I am being irresponsible. How so?

As I originally stated, I've been cleared by my doctors, note plural. My cardiologist, my cardiothoracic surgeon and my DO have cleared me; point of fact I was cleared 2 weeks post-op and returned to training, though I eased back into it the day I was cleared. For each additional activity I've added to my plate I've called my docs and sought their advice, IOW, 'hey doc, I'm thinking of going back to playing lacrosse, is that acceptable?' Or, 'hey doc, I'm thinking of running in this triathlon, is that acceptable?' As I also stated, I know I can run 3.1 miles (I've been averaging 8 minute miles for this distance and longer) and this past Saturday rode a century (100 Miles at an average of 17 mph).

So I've talked with my physicians - check, that's responsible, irresponsible would be not getting cleared by them and doing it.

I've trained for all but the swimming - But I have been swimming, just not training for a distance of 750 meters. Check, that's responsible. Naive maybe, but responsible.

I've sought out suggestions from those who compete in triathlons to see if I was delusional or not; all but one think it is more than feasible - check that's responsible.

So, again, I ask you, in what way am I exhibiting a lack of responsibility?

Just to inject a note of sanity here, I agree with tri-ac.
Recall that initially I suggested it was absurd to expect an answer to your question without knowing anything about you?

What we know and you don't - and neither can your doctors
is that in the swim start, which is affectionately called "the washing machine" in big races, you can be abused physically, and a panic attack is possible. Can your cardiac condition take that? I dunno, and unless your doc is a triathlete he hasn't got a freakin' clue what that's like.

So, like others have said above, the distance and effort of a sprint tri is likely within your capability.
Get in the wrong place at the wrong time and all bets are off.

As to being irresponsible or not, only you can judge. Do you have dependents? Got life insurance? I'm not your counselor, but before you leap take a hard look.
If you do it, great, just stay at the back from the start and remind yourself constantly,
"I am here to finish, not to win."

best of luck to you,

PoC