Background: The arterial waveform in young adults is ascribed to the combination of a forward wave from the ventricle and a reflection arriving at the aortic root in diastole. With ageing, the reflected wave is proposed to arrive earlier, augmenting systolic pressure and increasing afterload. This view has been recently disputed[1] and it is suggested that pressure in diastole is attributable to an arterial ‘reservoir’. We undertook a systematic review to ascertain whether reflected waves arrive in diastole.

Methods and Results: We searched the literature using PubMed and Cochrane. We identified 67 studies describing 139 cohorts totalling 13,957 subjects (mean age 53 years, range 4–91). The arrival time of waves was calculated from the time of the shoulder on the pressure waveform and the end of systole was estimated by the time of the dicrotic notch.

The arrival time of the reflected wave was 135.5 (95% CI 131.7–139.4) ms. In comparison, the end of systole occurred at 328.1 (314.0–342.2) ms. All reflection times were in the first two-thirds of systole. The peaks of the reflected pressure arrived at an average of 217.6 (207.8–227.4) ms, well within systole, across the age spectrum.

Conclusion: The mean time of arrival of the reflected wave is in systole even in the youngest subjects. These observations do not support the view that reflected waves typically arrive in diastole.