Assessment of The Correlation Between Doppler Derived dP/dt and Aortic Velocity-time Integral During Cardiac Resynchronization Therapy Optimization

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) was 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. 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. A total of 46 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). In conclusion, aVTI recorded at different pacing configurations was not correlated with dP/dt during interventricular optimization. However, both parameters consistently showed a positive effect of biventricular pacing on contractile synchronization and stroke volume.