Though you may obtain heap information using JVMPI, I don't think raw heap dump would be of any help. You may want to look at run-time
J2EE monitoring tools from Borland or Quest - they may provide more readable information.
Also it makes a lot of sense to run load tests of your application under profiler in QA environment. Please check this as well:
http://jroller.com/page/imeshev/20040204