To Pulse or Not to Pulse, Is That the Question?
Efferent sympathetic nerve discharge is both gated to the cardiac cycle and inhibited by afferent input from cardiac, aortic and carotid mechanoreceptors stimulated by rhythmic atrial and conduit artery distension. In patients with chronic heart failure as a consequence of impaired systolic function (HFrEF) both this gating and the blood pressure → muscle sympathetic nerve activity (MSNA) relationship are preserved1-3. The evolution of mechanical left ventricular support from devices that generate a pulse wave to those that propel blood continuously thus raises a number of intriguing questions regarding the body's adaptation to this alien physiology: what effect does acute or long term diminution or loss of arterial pulse pressure have on the neural regulation of the heart and circulation by the baroreceptor reflex? What impact do such changes have on endothelial biology, autoregulation of regional blood flow, and tissue or organ perfusion?
- blood pressure
- left ventricular assist device
- sympathetic nerve activity
- Received October 19, 2015.
- Accepted October 20, 2015.