| Summary: | Arterial pressure and flow waves travel and are reflected. Waveform analysis and wave separation gave insight into these phenomena and parameters thus obtained are indicators of cardiovascular events. However, the interpretation of forward and reflected waves is still not generally agreed upon. We used an anatomically accurate (data from Hickson, 2010) model of the entire systemic arterial tree and also set all aortic diameters equal at mean aortic diameter (“uniform aorta”), leaving other arteries unchanged, and calculated forward and backward waves in the standard way (Murgo, 1981). In the anatomically accurate model, timing of the feet of backward and forward waves is location independent, as also recently reported by Tyberg, 2013. In the uniform aorta the delay between forward and backward waves is smallest in the distal aorta and largest in the ascending aorta. In both models pressure amplification over the aorta is ∼1.35. Changes in microcirculatory resistance have little effect on wave shapes. We conclude that multiple local reflections in the aorta importantly contribute to pressure (and flow) wave shape. Thus pressure wave shapes depend on arterial geometry: aortic diameters and side branches. Distal aortic (bifurcation) and peripheral reflections are not the major contributors to overall reflection and wave shape. We suggest that studies of aortic dimensions and effect of side branches are needed to better understand aortic pressure wave shapes and wave travel.
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