Enlarged heart, murmur, Vetmedin... thoughts?

[Crysser]

Hi everyone,
I just had my little guy Joe (who is 11 years old) in to the vet. He's been coughing for the past week or two, especially when running around and playing with his toys. At first I thought it was his narrow trachea- I'd had him radiographed before, Dr prescribed hycodan, he was fine for quite some time. Joe has been acting normally- eating and drinking ok, activity is normal, he doesn't even slow down when he's coughing or wheezing. But I began to get more suspicious when I noticed him coughing in the mornings after waking up. I'm a vet assistant (only Saturdays now though), so I started thinking this could be something else and brought him in. My boss heard a heart murmur, he said maybe grade 3, and we got chest rads. His heart was enlarged, in addition to his narrow trachea. His lungs and the rest of his chest were clear though- no fluid accumulation, so at the very least he doesn't have congestive heart failure. So my boss prescribed Vetmedin for him, and we're also sending blood for a geriatric panel. So here we are.
So I suppose now I'd be interested to hear what experience anybody has had with heart murmurs and enlarged hearts and Vetmedin? I've had quite a few patients at my clinic on Vetmedin, some lasted quite a while on it. But some Yorkie-specific perspectives would be appreciated.

[Wylie's Mom]

My Wylie has a murmur (Grade 5) and pre-CHF/CHF...he's been on enalapril for about 3+ years now and does just great on it. He is almost 12 now.