Intrathoracic impedance monitoring with audible alert in heart failure management

Intrathoracic impedance monitoring with audible alert in heart failure management

Intrathoracic impedance monitoring with audible alert has been tried in heart failure management. This technology incorporated in heart failure devices {cardiac resynchronization therapy (CRT)} and implantable cardioverter-defibrillator (ICD) is used to assess the volume status and advice early hospitalization if needed. Dirk J van Veldhuisen, Frieder Braunschweig, Viviane Conraads, Ian Ford, Martin R Cowie, Guillaume Jondeau, Josef Kautzner and Roberto Muñoz Aguilera, Maurizio Lunati, Cheuk Man Yu, Bart Gerritse, Martin Borggrefe the DOT-HF Investigators from the Department of Cardiology, University Medical Center Groningen, University of Groningen, Netherlands studied 335 patients with chronic heart failure who had undergone implantation of CRT or ICD [1].

Heart failure patients get hospitalised frequently due to worsening of heart failure often associated with volume overload. Intrathoracic impedance measurement with an audible alert may give early indication of retention of fluid in the lungs and help patients seek medical advice before they become too sick.

Of the 335 patients with chronic heart failure in the study, 18% had an ICD (implantable cardioverter defibrillator) alone while 82% had CRT (cardiac resynchronization therapy as well. All patients had intrathoracic impedance (OptiVol). They were randomized to have information available to physicians and patients as an audible alert in case preset threshold was crossed (access arm) or not (control arm).

According to the authors, though the device increased heart failure hospitalizations and outpatient visits in heart failure patients, it did not improve the final outcome in terms of mortality or heart failure hospitalizations.

Reference

1. Dirk J van Veldhuisen, Frieder Braunschweig, Viviane Conraads, Ian Ford, Martin R Cowie, Guillaume Jondeau, Josef Kautzner, Roberto Muñoz Aguilera, Maurizio Lunati, Cheuk Man Yu, Bart Gerritse, Martin Borggrefe, DOT-HF Investigators. Intrathoracic Impedance Monitoring, Audible Patient Alerts, and Outcome in Patients With Heart Failure. Circulation. 2011 Oct 18;124(16):1719-26.