In psychiatry, Heim works in private practice, subspecializing in psychotherapy. He teaches medical undergraduates and lectures to trainee psychiatrists. He researches on the arts/health interface and is an Associate Senior Lecturer at the University of Queensland. In music, Heim held academic lecturing posts in music at the University of Wollongong and the University of Newcastle and lectured at the Manhattan School of Music. His musical Starlight unofficially opened the Hope Theatre, Wollongong. His findings on the effects of baroque music on dementia patients were published in Australasian Journal of Ageing in early 2004. They were described on the Australian Broadcasting Corporation's Radio National program, The National Interest in July 2004. A grant from the Bernard Judd Foundation enabled further publications in this area. Move Records released a CD of his work Prayer Dances featuring the Sydney Chamber Choir and Sprung Percussion. He composed the music for and directed theatre productions for Crossbow Productions. These include Maxwell Anderson’s Mary of Scotland, Shakespeare’s Measure for Measure, Anderson’s Anne of the Thousand Days, William Gibson’s The Miracle Worker, William Nicholson’s Shadowlands, and Sartre’s No Exit among others. These productions provided the basis for academic publications on topics such as cultural issues and theatre, catering for people with disabilities, and the role of consciousness in Meisner-based acting. Mardi Lumsden of JourneyOnline felt his 2010 direction of Shadowlands, a play written by William Nicholson, "is an innovative adaptation... with the introduction of live music, sculpture and mine." Caitlin Graham of Australian Stage felt that due to "some clumsy and fussy direction" it "falls short" whilst "The music and the sculpture are lovely and create a nice atmosphere." Heim delivers public lectures on topics combining psychiatry and music. These include: "Baroque & the Brain Wave: can music help in dementia care?" to the Royal Society of New South Wales ;" "An Afternoon with Frederic Chopin and George Sand" where he played piano in a portrayal of Chopin with Caroline Heim as Sand; and “Beethoven’s Immortal Beloved” where he explored the psyche of the composer who never married. He writes books aimed at improving relationships and preventing mental health problems.
