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This study investigated the effects of cardiac properties variability on arterial pulse wave morphology using blood flow modelling and pulse wave analysis. A lumped‐parameter model of the left part of the heart was coupled to a one‐dimensional model of the arterial network and validated using reference pulse waveforms in turn verified by comparison with in vivo measurements. A sensitivity analysis was performed to assess the effects of variations in cardiac parameters on central and peripheral pulse waveforms. Results showed that left ventricle contractility, stroke volume, cardiac cycle duration, and heart valves impairment are determinants of central waveforms morphology, pulse pressure and its amplification. Contractility of the left atrium has negligible effects on arterial pulse waves. Results also suggested that it might be possible to infer left ventricular dysfunction by analysing the timing of the dicrotic notch and cardiac function by analysing PPG signals. This study has identified cardiac properties that may be extracted from in vivo central and peripheral pulse waves to assess cardiac function.

BackgroundArterial stiffening and peripheral wave reflections have been considered the major determinants of raised pulse pressure (PP) and isolated systolic hypertension, but the importance of cardiac contractility and ventricular ejection dynamics is also recognised.MethodsWe examined the contributions of arterial compliance and ventricular contractility to variations in aortic flow and increased central (cPP) and peripheral (pPP) pulse pressure, and PP amplification (PPa) in normotensive subjects during pharmacological modulation of physiology, in hypertensive subjects, and in silico using a cardiovascular model accounting for ventricular–aortic coupling. Reflections at the aortic root and from downstream vessels were quantified using emission and reflection coefficients, respectively.ResultscPP was strongly associated with contractility and compliance, whereas pPP and PPa were strongly associated with contractility. Increased contractility by inotropic stimulation increased peak aortic flow (323.9 ± 52.8 vs. 389.1 ± 65.1 ml/s), and the rate of increase (3193.6 ± 793.0 vs. 4848.3 ± 450.4 ml/s2) in aortic flow, leading to larger cPP (36.1 ± 8.8 vs. 59.0 ± 10.8 mmHg), pPP (56.9 ± 13.1 vs. 93.0 ± 17.0 mmHg) and PPa (20.8 ± 4.8 vs. 34.0 ± 7.3 mmHg). Increased compliance by vasodilation decreased cPP (62.2 ± 20.2 vs. 45.2 ± 17.8 mmHg) without altering dP/dt, pPP or PPa. The emission coefficient changed with increasing cPP, but the reflection coefficient did not. These results agreed with in silico data obtained by independently changing contractility/compliance over the range observed in vivo.ConclusionsVentricular contractility plays a key role in raising and amplifying PP, by altering aortic flow wave morphology.

The development of methodologies that provide a comprehensive assessment of cardiac function from pulse wave analysis in the systemic circulation could avoid current practice using expensive, invasive and operator-dependent measurement techniques. This work addressed this topic computationally. A cardiovascular model, constituted of a lumped-parameter model of the left part of the heart coupled to a one-dimensional model of the arterial network, was validated using reference pulse waveforms in turn verified by comparison with in vivo measurements. The validation was specifically designed to verify the performance of the model in returning physiological pulse waves for assigned cardiac properties. Successively, a sensitivity analysis was performed to assess the effects of variations in cardiac parameters on central and peripheral pulse waves. Results show that left ventricle contractility, stroke volume, cardiac cycle duration and heart valves impairment are determinants of central waveforms morphology, pulse pressure and its amplification. Contractility of the left atrium has negligible effects on vascular pulse waves. Results also suggest that it may be possible to infer left ventricular dysfunction by analysing the timing of the dicrotic notch. This study suggests which cardiac properties can be extracted from central and peripheral pulse waves to assess cardiac function.