CrossTalk opposing view: Forward and backward pressure waves in the arterial system do not represent reality

For several decades, impedance analysis has been almost universally employed by physiologists to study arterial haemodynamics and by physicians to explain changes in the aortic pressure waveform that occur with ageing and disease (Laurent et al. 2006). This analysis has led to the concept of a wave being reflected from some distal reflecting site that accounts for systolic pressure augmentation and the ‘augmentation index’. Evidence has arisen recently that leads us to question this conventional wisdom. The history of arterial haemodynamics goes back more than a century; notably, to the work of the German physiologist, Otto Frank, who applied the concept of the ‘Windkessel’ to the mechanics of the compliant aorta (Frank, 1899). The Windkessel was an air-filled reservoir that was used in primitive fire-fighting equipment to provide steady