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