Where Are We Heading with Noninvasive Clinical Vascular Physiology? Why and How Should We Assess Endothelial Function?

Figure 2

An example of the effect of salbutamol and glyceryl trinitrate (GTN) on the radial waveform in a single individual. The second systolic peak, obvious at baseline, is attenuated by salbutamol and almost completely abolished following GTN. Augmentation index (AIx), calculated as the ratio of the pulse pressure at the second systolic peak to that at the first systolic peak is used to quantify the changes in the waveform. BP = blood pressure. Printed with permission from [33].