The prediction of individual systolic time interval v heart rate regression equations.

1. Twenty-eight sets of systolic time interval (STI) and heart rate (HR) data were available from studies in which small bolus doses of atropine had been given to alter heart rate. 2. Regression lines of the form LVET = A+B.HR and QS2 = C+D.HR were calculated. There was no significant relationship between PEP and HR. The values of the parameters A-D were normally distributed. 3. The maximum likelihood Estimation was used to obtain the most likely values of the parameters A-D for individual subjects. 4. The technique proved to be highly satisfactory and was subsequently validated with a further six sets of data.