This research study is designed to determine: 1) whether gene transfer using an agent called Ad5.hAC6 (adenovirus-5 encoding human adenylyl cyclase type 6) can be given safely to patients with congestive heart failure (CHF) and 2) whether this agent may be of benefit in heart failure. Gene transfer is a process by which genes are introduced into cells and the cells then produce the specific protein that the gene directs, in this case, a protein known as adenylyl cyclase type 6 (AC6). The gene is carried into the heart cells by a modified virus. The virus that is modified is an adenovirus (Ad5), a virus that sometimes causes a brief cold. In extensive animal experiments, it was found that increased amounts of AC6 protein in heart cells appear to make the heart pump more vigorously.