change in heart rate to change in mean arterial blood pressure ratio maximum change in heart rate to change in mean arterial blood pressure ratio Maximum, largest or steepest slope of the line defined by the change in heart rate (the number of contractions of the cardiac ventricles per unit of time) relative to the change in mean arterial blood pressure (the average blood pressure within an artery over a specified period of time) over time and/or in response to a change in conditions. 2014-01-07T16:53:44Z CMO:0002037 jsmith clinical_measurement_ontology VT:2000009