New approaches to monitoring heart failure before symptoms appear.

Intrathoracic impedance monitoring (approved by the US Food and Drug Administration) and implantable hemodynamic monitoring (IHM), which is under investigation, are promising techniques for the improved management of heart failure by detecting early changes in fluid status or hemodynamic congestion. Routine outpatient surveillance of intrathoracic impedance data from implanted devices may significantly reduce the currently high rates of hospital admission/readmission for patients with heart failure. IHM systems may extend such monitoring capabilities. Both emerging approaches for monitoring patients with heart failure may alert clinicians (and possibly patients) to impending decompensation before symptoms appear.