Measuring Nonpulsatile Blood Pressure

Abstract

We are in a unique era of human physiology: the era of nonpulsatility. The benefits of pulsatile blood pressure (BP) have been debated for decades, but now this debate is growing with the emergence of continuous flow left ventricular assist devices (LVAD) as an accepted therapy for patients with refractory heart failure. The question is this: do humans require pulsatile BP for adequate end-organ function in the acute and chronic settings; or to turn the question around: are humans deleteriously affected by nonpulsatile flow? Article see p 1005 The short- and medium-term outcomes associated with continuous flow LVADs are well known and have significantly improved as compared with first generation pulsatile devices.1–3 Current devices are more durable, with smaller rotors, pumps, and drive lines. Indeed, we have seen a steady rise in the adoption and application of LVADs over the last several years (ie, the HeartMate II continuous flow device was approved for bridge to transplant [BTT] in 2008 and destination therapy [DT] in 2010; the HeartWare device was approved for BTT in 2012). Despite lack of pulsatile flow in the arterial system, end-organ function improves as compared with the preimplant state.2 Nevertheless, we have much to learn about these devices, particularly how to optimize pump speed for long-term use (potentially over the course of decades), …