OptiVol fluid status monitoring with an implantable cardiac device: a heart failure management system.

Early intervention and prevention of hospitalizations would reduce the burden of heart failure on the healthcare system while improving the quality of life of affected patients. Traditional methods of patient assessment, including physical examination and patient report of symptoms, have a low sensitivity for detecting elevations in left ventricular filling pressure, a major precursor of pulmonary congestion and heart failure decompensation. Intrathoracic fluid accumulation during pulmonary congestion leads to decreased impedance across the lung. The OptiVol system in the InSync Sentrycardiac resynchronization therapy-defibrillator, Concerto cardiac resynchronization therapy-defibrillator and Virtuoso implantable cardioverter-defibrillator devices monitors intrathoracic impedance and is intended to recognize early signs of volume accumulation before physical symptoms appear. Through a recent clinical trial, the default setting for the OptiVol system functioned as a predictor of hospitalization with 76.9% sensitivity. Intrathoracic impedance monitoring is not intended to replace careful frequent clinical evaluation of the heart failure patient, but instead aims to complement traditional heart failure management practices.