Arterial transfer functions and the reconstruction of central aortic waveforms: myths, controversies and misconceptions

Continuing reports in the literature regarding the potential of central pulse wave analysis in clinical practice and a recent consensus statement demonstrate the increasing interest in the clinical application of arterial transfer functions. A number of misconceptions, however, persist regarding their use. In spite of ongoing controversy, there are considerable published data that would permit users to assess the validity and accuracy of the technique. We provide a comprehensive review of available data, all of which appear to be clear and consistent. The technique does not permit accurate reconstruction of central waveforms from entirely non-invasively acquired data. We should move on from the misconception that what is being studied is central aortic data when transfer functions are applied non-invasively, and accept that it is radial waveform data that have been passed through a single mathematical transformation. We have a readily applicable, non-invasive and reproducible technique for acquiring radial waveform data, with or without the application of a generalized arterial transfer function. We must explore the potential of this technique in an analytical manner, and without untenable preconceptions, if we are to learn the secrets that it may yet reveal.