Carotid Pulse Wave Analysis: Future Direction of Hemodynamic and Cardiovascular Risk Assessment

Abstract

Evaluation of the hemodynamic function of the cardiovascular system via measurement of the mechanical properties of the large arteries may provide a substantial improvement over present techniques. Practitioners are familiar with the problem of low reproducibility of conventional sphygmomanometry, which exhibits reasonable accuracy but low precision owing to its marked variability over time and in different circumstances (e.g., the white coat effect). Arterial wall stiffness is a consequence of atherosclerosis developing over time; thus, it has little short-term variability and is thus preferable to be used as a prognostic marker. In particular, arterial stiffness can be evaluated at the carotid artery using noninvasive approaches based on wearable sensor technologies for pulse wave analysis. These enable the assessment of central pressures and pulse waveform parameters that are expected to replace peripheral blood pressure measurement using the inflatable cuff. In this study, we discuss this simple and inexpensive technique, which has been shown to be reliable with the clinical and epidemiological evidence for its use as a biomarker of cardiovascular risk.

Keywords: arterial stiffness; atherosclerosis; cardiovascular diseases; carotid artery; pulse wave analysis; wearable sensors.

Figure 1.

Amplification of the pressure waveform moving from the aorta (a) to the brachial (b), carotid, (c) and radial arteries (d). cf-PWV or aortic PWV is a ratio of the distance D-d and the transit time Δt between the carotid and femoral arteries.

Figure 2.

Analysis of central pulse pressure waveform.

Figure 3.

Cycle of increasing blood pressure due to structural and functional vascular changes.

Figure 4.

Wearable and noncontact sensors for measuring carotid pulse wave using e-Health system.