Continuous ambulatory haemodynamic monitoring with an implantable system. The feasibility of a new technique.

AIMS This study evaluates the feasibility and safety of a completely implantable system for long-term ambulatory monitoring of important haemodynamic parameters in patients with severe cardiopulmonary disease. METHODS The design of the implantable monitoring system is similar to a conventional single lead pacemaker. A lead with incorporated biosensors for the continuous recording of pressure and oxygen saturation signals is positioned in the right ventricle and connected to a monitor and memory device subcutaneously implanted like an ordinary pacemaker can. RESULTS Five patients with implanted haemodynamic monitoring systems have been followed for from 7 to 16 months. Continuous measurements of activity, heart rate, mixed venous oxygen saturation and estimated pulmonary artery diastolic pressure were registered with variable resolution during daily living and predefined provocations. The memory covered a maximum of 3 weeks at low resolution. The monitored parameters showed an adequate and significant response to various haemodynamic situations. Except for the demand of recalibration of two oxygen sensors, there were no technical problems and the quality of data were excellent. CONCLUSION Long-term ambulatory haemodynamic monitoring is feasible and potentially useful for the management of patients with severe cardiopulmonary disease.