The role of the central nervous system in sudden cardiac death: Heartbeat dynamics in conscious pigs during coronary occlusion,psychologic stress and intracerebral propranolol

Electrocardiograms were recorded in conscious pigs during psychological stress (touching), left anterior descending coronary artery occlusion, intracerebral levo-propranolol (0.05 mg/kg), and their respective controls. The R-R intervals were evaluated with both a deterministic measure (point correlation dimension) and a stochastic one (mean). Only the deterministic measure was sensitive to between-subject responses (P<.01), whereas both measures were sensitive to within-subject changes. The results are explained by a deterministic model of heartbeat generation. Supported by the National Institute of Health Grant NS 27745.