Long-term recording of cardiac output via an implantable haemodynamic monitoring device

• Published in: European heart journal 1996-12, Vol.17 (12), p.1902-1910
• Main Authors: Ohlsson, Å, Bennett, T., Ottenhoff, F., Bitkover, C., Kjellström, B., Nordlander, R., Åström, H., Rydèn, L.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Biological and medical sciences; Cardiac Output; Cardiology. Vascular system; Chronic Disease; Equipment Design; Female; Fick principle; Heart; Heart Failure - diagnosis; Heart Failure - physiopathology; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Hemodynamics - physiology; Humans; implantable; Long-Term Care; long-term monitoring; Male; Medical sciences; Middle Aged; Monitoring, Physiologic - instrumentation; Monitoring, Physiologic - methods; Reference Values; Reproducibility of Results; Sensitivity and Specificity
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/oxfordjournals.eurheartj.a014810

Long-term monitoring of central haemodynamics with implanted monitoring systems might be valuable in managing heart failure patients. Such systems offer an opportunity for repeated ‘semi-invasive’ cardiac output determinations according to the Fick principle. Five patients, four with chronic heart failure and one with chronic pulmonary disease, underwent supine exercise testing during cardiac catheterization at 0, 2, 6 and 11 months after implantation of a right ventricular mixed venous oxygen saturation sensor connected to an implantable haemodynamic monitor. The monitor provided a continuous measure of oxygen saturation via a radio-telemetry link to a metabolic cart capable of measurement of breath-by-breath oxygen consumption. Cardiac output was computed using oxygen consumption, mixed venous oxygen saturation, arterial oxygen saturation by pulse oximetry and haemoglobin oxygen capacity. Biosensor-derived oxygen saturation compared to blood samples from the pulmonary artery showed an excellent correlation over time, r2=0.94 (implant), r2=0.91 (6–11 months). There was a strong correlation between semi-invasive-determined cardiac output using the biosensor and the invasive technique, which persisted over the entire follow-up period. Repeated semi-invasive cardiac output measurements using an implanted haemodynamic monitoring system in chronic heart failure patients is feasible and the data may be of value for optimizing therapy.