"Summation" of the increase in heart rate from stimulation of atrial receptors.
D000818:Animals; D016275:Atrial Function; D002320:Cardiovascular Physiological Phenomena; D004285:Dogs; D004558:Electric Stimulation; D004562:Electrocardiography; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D009020:Morphine / Q000494:pharmacology; D011984:Sensory Receptor Cells / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology; D013565:Sympatholytics / Q000494:pharmacology
D013565:Sympatholytics; D009020:Morphine