The diffusible second messenger cAMP mediates responses to a wide array of neurotransmitters and hormones acting through a variety of G-protein coupled receptors (GPCRs) in virtually every cell in the human body, including those of the heart. The cAMP signaling pathway plays a critical role in regulating many different aspects of cardiac myocyte function, including gene transcription, cell metabolism, and excitation-contraction coupling. However, not all GPCRs that stimulate cAMP production produce the same responses. Subcellular compartmentation of cAMP is essential to explain how different receptors can utilize the same diffusible second messenger to elicit unique functional responses. Furthermore, disruption of cAMP compartmentation has been linked to various disease states, including cardiac hypertrophy, heart failure, and arrhythmias. Yet, many questions remain concerning the mechanisms contributing to cAMP compartmentation. This talk will summarize some of the work our lab has conducted using a variety of experimental and computational approaches to shed light on these questions.