Left ventricular resynchronization in H.F.: Comparison of alternative optimization methods

This paper compares the results of two different procedures, Doppler Ultrasound and Transthoracic Impedance, to monitor the left ventricular stroke volume on a group of heart failure patients submitted to electrical resynchronization therapy. The two procedures have been applied in parallel on 9 patients by changing the stimulation delays between the septal and posterior ventricular walls and the results have been compared to evaluate the correlation between the two choices, and their sensitivity to detect the optimal stimulation condition. The results demonstrated a good agreement between the data obtained with the two procedures (R=0.82), but a very limited change of the target parameter (Stroke Volume) by changing the stimulation delay. This suggests doubts on the choice of stroke volume as the best parameter to be observed for the optimization process and on the adequate sensitivity of the two procedures to highlight the process.