Feasibility of Using an Implantable System to Measure Thoracic Congestion in an Ambulatory Chronic Heart Failure Canine Model
- 3 May 2005
- journal article
- Published by Wiley in Pacing and Clinical Electrophysiology
- Vol. 28 (5), 404-411
- https://doi.org/10.1111/j.1540-8159.2005.40009.x
Abstract
Background: Noninvasive measures of impedance reflect alterations in thoracic fluid and pulmonary edema in acute animal and human studies. Materials and Methods: We evaluated the feasibility of using an implantable impedance measuring device and cardiac lead system to monitor intrathoracic congestion in a pacing-induced heart failure canine model. Three devices were implanted in each of five dogs: a modified pacemaker to measure impedance from a defibrillation lead implanted in the right ventricle; an implantable hemodynamic monitoring device to measure left ventricular end diastolic pressure (LVEDP) and a second pacemaker to deliver rapid (240 pulses per minute) ventricular pacing to induce heart failure. Results: All five dogs developed severe heart failure after 3–4 weeks of rapid pacing and recovered following pacing termination. The LVEDP increased and impedance decreased during pacing-induced heart failure and recovered after pacing cessation. At the end of pacing, there was a mean impedance reduction of 10.6 ± 8.3% and a mean LVEDP increase of 18.1 ± 4.5 mmHg compared to baseline. The impedance and LVEDP were inversely correlated (r =−0.41 to −0.85, all P < 0.05). Conclusions: In the canine model, measurement of chronic intrathoracic impedance with an implantable system effectively revealed changes in thoracic congestion due to heart failure reflected by LVEDP. These data suggest that implantable device-based impedance measurement merits further investigation as a tool to monitor the fluid status of heart failure patients.Keywords
This publication has 18 references indexed in Scilit:
- Cardiac-Resynchronization Therapy with or without an Implantable Defibrillator in Advanced Chronic Heart FailureThe New England Journal of Medicine, 2004
- Prophylactic Implantation of a Defibrillator in Patients with Myocardial Infarction and Reduced Ejection FractionThe New England Journal of Medicine, 2002
- Delays in seeking treatment for symptoms: A new or overlooked dilemma in the care of heart failure patientsJournal of Cardiac Failure, 1999
- Tachycardia-Induced Cardiomyopathy: A Review of Animal Models and Clinical StudiesJournal of the American College of Cardiology, 1997
- Multiple sources of the impedance cardiogram based on 3-D finite difference human thorax modelsIEEE Transactions on Biomedical Engineering, 1995
- Evaluation of transthoracic electrical impedance in the diagnosis of pulmonary edema.Circulation, 1979
- Noninvasive Measurement of Intrathoracic FluidsSocial psychiatry. Sozialpsychiatrie. Psychiatrie sociale, 1974
- Monitoring the Chest with ImpedanceSocial psychiatry. Sozialpsychiatrie. Psychiatrie sociale, 1973
- Transthoracic electrical impedance: Quantitative evaluation of a non-invasive measure of thoracic fluid volumeAmerican Heart Journal, 1973
- Clinical Evaluation of Transthoracic Electrical Impedance as a Guide to Intrathoracic Fluid VolumesAnnals of Surgery, 1970