Purpose: Suboptimal response to cardiac resynchronization therapy (CRT) may be improved by optimization of device parameters using echocardiography. For this purpose, the aortic velocity-time integral (aVTI) has been used as a target metric to define optimal velocity timings for each ventricle. dP/dt is a parameter used for the assessment of myocardial contractility. In this study, we aimed to evaluate the effectiveness of Doppler-derived dP/dt in optimization by assessing the possible correlation between aVTI and dP/dt.
Methods: Patients with CRT admitted for routine follow-up were included in the study. Aortic VTI and dP/dt measurements were recorded in four different standard pacing configurations during reprogramming.
Results: A total of 45 patients were included in the final analysis. No correlation was found between the aVTI and the delta dP/dt value in the two configurations where the change in dP/dt was maximum (p = 0.894). In the two configurations where the change in aVTI was maximum, there was also no correlation between the delta dP/dt and the delta aVTI (p = 0.715). When patients were dichotomized according to the median value of dP/dt, there were no differences in aVTI, NYHA classes, LVEF, and mitral regurgitation (MR) severity (p = 0.4; p = 0.5; p = 0.7; p = 0.3; respectively). The change in both dP/dt and aVTI was statistically significant when switching from RV-only to QRS width-targeted configuration (p = 0.001; p = 0.041; respectively).
Conclusion: In conclusion, aVTI recorded at different pacing configurations did not correlate with dP/dt during interventricular optimization. However, both parameters consistently showed a positive effect of biventricular pacing on contractile synchronization and stroke volume.
Keywords: Aortic velocity-time integral.; Cardiac Resynchronization Therapy optimization; Doppler Derived dP/dt; Echocardiography; Interventricular Delay.
© 2024. The Author(s), under exclusive licence to Springer Nature B.V.