Figure 2 (A) Simultaneous recording of electrocardiogram and ascending aortic pressure. Millar and M‐mode echocardiogram showing that the upstroke of the arterial pressure curve (U) coincides with the aortic valve (Ao) opening (O) from the M‐mode recording and that the dicrotic notch (D) coincides with aortic valve closure (C). From Minich et al⁷; reproduced with permission of the publishers. (B) For clarity, schematic diagram of the same events.