Four-terminal impedance monitoring of cardiac output: an elegant clinical application of a classical engineering trick

Abstract

This editorial refers to 'Intracardiac impedance monitors stroke volume in resynchronization therapy patients' by M. Bocchiardo et al., on page 702. Nothing is more basic to life than cardiac output. However, an accurate method to monitor cardiac output with an implantable device has long eluded device developers. In this issue of the Journal, Bocchiardo et al. 1 present significant progress toward that end with encouraging human data.