engleski

Hemodynamic sensor in stylet channel : acute human experiment

Cardiac contractions bend the lead body and extend and compress lead conductors and lead strain sensor inserted within the lead. Previous studies proved that lead strain measured by electrostatic discharge sensor (EDS) is representative of cardiac contractions. The purpose of this study was to evaluate EDS signal in various phases of lead strain utilizing X-ray fluoroscopy video analysis. Methods: In 16 patients undergoing single and dual chamber pacemaker implantation, EDS was temporarily inserted within lead stylet channel. Ventricular and optionally atrial EDS signals, intracardiac electrograms, patient’s ECG and X-ray fluoroscopy video were recorded synchronously during routine lead testing. Inner lead’s conductor and conductive proximal end of EDS were connected to custom designed amplifier. Correlation of EDS signals with lead bending in different angles fluoroscopy views was analyzed subsequently. Results and Conclusion: EDS signal recording was possible in all patients and in both chambers. Deflection of the ventricular lead occurred in its distal segment at curvature within the tricuspid valve. Ventricular contractions pulled the right ventricular segment of lead in cranial direction thereby flexing the tricuspid and low atrial segments of the lead. Atrial contractions resulted in deflection of atrial lead in its J-shaped segment. Maximum of EDS signal corresponds to maximum of the systolic lead deflection caused by cardiac contraction. Minimum of the EDS signal corresponds to the end diastole whereby lead is minimally deflected. EDS signal amplitude was proportional to magnitude of the lead bending. Different positions of the lead tip implantation yielded different lead deflection and different EDS signal magnitude. Periodic variation of EDS signal exactly corresponds to periodic variation of bending curve of the RV lead. Its parameters depend on cardiac contraction’s mechanical properties. It could therefore be used as hemodynamic sensor in implantable devices for arrhythmia detection and heart failure monitoring.

hemodynamic sensor; cardiac lead; myocardial contractility

nije evidentirano