부산대학교 도서관

Introduction: Hemodynamic parameters are used to monitor and guide in patient therapy for heart failure but are not accessible continuously in the ambulatory setting. We investigated whether ICD-based dynamic cardiogenic impedance (CI) monitoring can be used as a surrogate for hemodynamic parameters including stroke volume (SV) and blood pressure.Methods: We analyzed dynamic CI data from 11 impedance configurations recorded in 9 anesthetized animals undergoing rapid atrial or ventricular pacing to mimic tachyarrhythmias. We correlated beat-to-beat CI morphology metrics to SV and cardiac output (CO), mean arterial pressure (MAP) and the drop in MAP caused by the arrhythmia (ΔMAP) before and during the mimicked arrhythmias. SV and CO were estimated from measurements of carotid artery blood flow. We assessed the correlation coefficient and the standard error to the mean.Results: The correlation coefficients between CI and the hemodynamic parameters across all animals using all impedance configurations showed that CI was most successful in estimating SV (R2=0.92), followed by MAP (R2=0.82), ΔMAP (R2=0.80) and CO (R2=0.78). The standard error of the mean was 0.042 l/beat (SV), 6.7 mmHg (MAP), 5.0 mmHg (ΔMAP) and 0.082 l/min (CO).Conclusions: CI has the potential to serve as a metric from which SV or other hemodynamic measures may be estimated during arrhythmias; this could provide for a more advanced means of ICD-based tachyarrhythmia therapy delivery. It may also provide for means to track hemodynamic parameters over time for diagnostic purposes.