I have only just learned of the very distressing heart disease problem (fibrosing cardiomyopathy), suffered by captive Lowland Gorillas and reported very well at:
http://www.msnbc.msn.com/id/23971635/
I have written to the National Zoo, Washington D.C., to see if there's anything I can offer by way of help. There has to be a simple explanation somewhere (although it may not be simple to find). The more minds on this, the better and the Alternative Medicine approach may shed different light on the topic.