Determining arterial wave transit time from a single aortic pressure pulse in rats: vascular impulse response analysis

Arterial wave transit time ( τ w ) in the lower body circulation is an effective biomarker of cardiovascular risk that substantially affects systolic workload imposed on the heart. This study evaluated a method for determining τ w from the vascular impulse response on the basis of the measured aortic pressure and an assumed triangular flow ( Q tri ). The base of the unknown Q tri was constructed with a duration set equal to ejection time. The timing of the peak triangle was derived using a fourth-order derivative of the pressure waveform. Values of τ w s obtained using Q tri were compared with those obtained from the measure aortic flow wave ( Q m ). Healthy rats ( n = 27), rats with chronic kidney disease (CKD; n = 22), and rats with type 1 ( n = 22) or type 2 ( n = 11) diabetes were analyzed. The cardiovascular conditions in the CKD rats and both diabetic groups were characterized by a decrease in τ w s. The following significant relation was observed ( P