When I was pregnant with my oldest who is now 22 ~ we were having a BBQ. I had a chow mix rescue Cheech (Cheech-O Mon Peach-O BahLeach-O) I loved that dog more than life itself. I was prepping for the BBQ and took 2 ribs to cook with the baked beans. These were uncooked country ribs that slid off the plate and hit the floor. Well before I got my big body bent over Cheech had grabbed one. No biggie, as it was an uncooked country rib... at least that's what I thought. He got that rib stuck on the left side of his mouth and wedged in his throat. Honest to Pete it the scariest choke I have ever seen in my life. And if I were totally honest it does edge out the choke my son had on a Dorito when he was about 4 although I probably wouldn't make that true confession to him. I cannot express how difficult it is to manage a choking dog, then add to that a very pregnant belly. I had to get a flathead screwdriver and pry that bone out of his mouth it would not come out with my fingers. Minutes seemed like hours! And then a trip to the vet, Cheecho was fine. Scary, there just aren't words and I know exactly how you feel. Because to this day if I think about that episode I still have a semi meltdown. That incident will stick with you forever.
As for the Murmur we currently have a 6 year old Beagle with a pretty serious one. She is my Mom's dogs. She tires easily and has coughing spells. The cough has a very unique sound, that we are all "used" to but if someone is around who isn't the look on their face when they hear it is total shock. Other than being the b1tchiest beagle I have ever encountered (she has a nasty attitude which is uncommon) she lives a normal, happy life. She just isn't able to exert herself like the other beagle and she doesn't run rabbits as she tires to easily. So even with a murmur just under the murmurs that require medication she lives a normal happy life. It really is no big deal and she is checked at the vet and she is fine although she isn't fine. So try not to be too worried about the murmur. The other Beagle has an allergy to grass and if I was forced to pick between having a dog with the murmur or a dog with the grass allergy, I would pick the murmur hands down. Mom has many more problems with the dog with the grass allergy. Not that I would want to have to pick, but just to show you a person would obviously think having to pick between those two conditions the allergy would be easiest and it's not. A murmur usually goes away and if it doesn't most of them are manageable.
So sorry you and your kids had to experience that, but thankful you were able to save her. Keep us posted on everything please.