ObjectiveDetermine whether blood pressure measured by a cuff on the forearm could be predicted better by upper arm cuff pressure or by radial pressure estimated by a transfer function method from the ascending aortic pressure wave.Subjects32 adults undergoing cardiac catheterization.MethodsBlood pressure was measured by cuffs on the forearm and upper arm and by a catheter in the ascending aorta. A transfer function was used to predict radial artery blood pressure from the ascending aortic pressure waveform. Regressions were computed between upper arm pressure measured by cuff and forearm pressure measured by cuff, and between predicted radial artery pressure and forearm pressure measured by cuff.ResultsThe transfer function method did not predict forearm systolic pressure as well as the upper arm cuff did (r=0.76 for the former, r=0.89 for the latter). For diastolic pressure and mean pressure, the transfer function method predicted slightly less well than the upper arm cuff (r=0.83 vs. r=0.87 for diastolic; r=0.77 vs. r=0.80 for mean).ConclusionsThe transfer function method does not predict forearm cuff blood pressure better than an upper arm cuff measurement. Supported by the University of Delaware Research Foundation.