IntroductionIt is reported that pressure wave reflection is enhanced by external compression of the femoral artery. Therefore, it is possible that cardiac catheterization itself can influence the aortic pressure waveform. AimThe purpose of this study is to clarify the influence of sheath placement in a femoral artery on the pressure waveform. MethodsThis study enrolled 21 pediatric patients (5.1±4.0years) who underwent cardiac catheterization. A sheath was placed in the femoral arteries of all patients. The change in the pressure waveform induced by the placement of the sheath was investigated using the b/a and d/a ratio of second derivative of a fingertip photoplethysmogram. A high b/a ratio means a stiff aorta and a low d/a ratio represents an enhancement of the aortic pressure wave reflection. ResultsBy the placement of the sheath in their femoral arteries, the b/a ratio was not influenced (sheath (−): −0.556±0.081 vs. sheath (+): −0.558±0.072; p=0.896). However, the d/a ratio was significantly decreased (−0.150±0.074 vs. −0.185±0.084; p=0.0003). ConclusionsThe placement of the femoral arterial sheath enhances the pressure wave reflection and would lead to a change in the central aortic pressure waveform.