Evaluation of factors related to the pulse Doppler waveform of the common carotid artery

The aim of this study is to evaluate factors related to the pulse Doppler waveform of the common carotid artery (CCA) in the systolic phase. Sixteen consecutive subjects who underwent carotid ultrasonography and transtho­ racic echocardiography (TTE) were included. Peak systolic velocity (PSV), time-averaged maximum velocity (TAMV), end diastolic velocity (EDV), pulsatility index (PI), resistance index (RI), the diameters of the CCA and internal carotid artery (ICA), the presence of ICA stenosis at the origin as well as the angle between the ICA and CCA were measured. The pulse Doppler waveforms of the CCA were categorized into the following three patterns: type A (15 vessels, bimodal peaks with the latter being small), type B (9 vessels, bimodal peaks with both peaks being equal or higher) and type C (8 vessels, a uninomodal peak). Valvular heart disease and left ven­ tricular ejection fraction were evaluated by TTE. The frequency of aortic regurgitation, EDV, TAMV and RI were different among the groups (p < 0.05, p < 0.1, p < 0.05, p < 0.1, respectively). In multivariate analysis, us­ ing Type A as the reference group, no parameters were associated with type B, but TAMV and RI were signifi­ cantly associated with type C. We conclude that the TAMV and RI of CCA might contribute to changes in the CCA waveforms.