Until relatively recently, Parkinson disease (PD) was viewed as mainly a movement dis-order, resulting from loss of nigrostriatal dopamine terminals in the brain. Almost all patients with PD, however, have symptoms or signs of dysfunction of the autonomic nervous system, 1 such as constipation, urinary incontinence, orthostatic or postprandial light-headedness, heat or cold intolerance, and orthostatic hypotension. Recent studies focusing on the sympathetic noradrenergic component of the autonomic nervous system have supported the concept that PD is not only a movement disorder but also a form of dysautonomia. This review provides an update on the status of the innervation of the heart in PD.