Intracardiac flow analysis in cardiac resynchronization therapy: A new challenge?

Abstract

In the past years, assessment of cardiac function has become possible through the analysis of intracardiac flow dynamics, performed noninvasively using phase‐contrast cardiac magnetic resonance and contrast and noncontrast ultrasound techniques. From 2013 to 2019, 9 echocardiographic investigations have considered 215 patients with cardiac resynchronization therapy (CRT) as a model for assessing flow dynamics within the left ventricle. Preliminary results have been reported about the acute hemodynamic effects of CRT and programming of the CRT device, showing the potential of an approach based on analysis of intracardiac flows. At present, there are only scarce data on the capability of intracardiac flow dynamics to predict LV remodeling after CRT and no information on clinical outcome prediction. Future investigations should be aimed at clarifying the mechanisms and impact of maladaptive intracardiac vortex dynamics on progressive LV remodeling as well as the prognostic meaning of implanted CRT device based on cardiac flow analysis.

Effect of Aging on Intraventricular Kinetic Energy and Energy Dissipation

“…Normalization, using the average KE, avoids direct dependence on LV KED from the LV size. Using the HyperFlow and HyperDoppler techniques, other energetic measures can be obtained-for example, the KE fluctuation, which is defined as the standard deviation Using the HyperFlow and HyperDoppler techniques, other energetic measures can be obtained-for example, the KE fluctuation, which is defined as the standard deviation of the KE, normalized by the corresponding average value [42]. KE fluctuation is informative of the degree of regularity in the flow (or, loosely speaking, of turbulence).…”

Noninvasive Evaluation of Intraventricular Flow Dynamics by the HyperDoppler Technique: First Application to Normal Subjects, Athletes, and Patients with Heart Failure

“…The geometrical vortex properties of this net circulatory region are expressed by the following measures: the vortex area, normalized with the LV area; the vortex intensity (i.e., the integral of the vorticity inside the vortex), normalized with the total vorticity; the vortex depth (the distance of its center from the LV base) and the vortex length along the base-apex direction, both normalized with the LV length. The energetic properties of the vortex flow are evaluated by calculating the total kinetic energy dissipation (KED), that is, the amount of kinetic energy dissipated into the heart (by viscous friction) during the cardiac cycle [11,12]. The total KED is the value integrated over the entire LV; it is usually normalized with the average kinetic energy to avoid direct dependence on the LV size [11,12].…”

“…The energetic properties of the vortex flow are evaluated by calculating the total kinetic energy dissipation (KED), that is, the amount of kinetic energy dissipated into the heart (by viscous friction) during the cardiac cycle [11,12]. The total KED is the value integrated over the entire LV; it is usually normalized with the average kinetic energy to avoid direct dependence on the LV size [11,12]. In the first 15 unselected patients at Center 1, the time needed for vortex analysis was measured as the time from starting to recall the stored color Doppler cineloop for analysis to the analysis output.…”

Left Ventricular Deformation and Vortex Analysis in Heart Failure: From Ultrasound Technique to Current Clinical Application

“…The role of intracardiac flow dynamics in predicting CRT response or guiding the site of LV lead implantation is not yet clear [ 58 ]. It has been shown, using the Echo-PIV technique, that in CRT responders, when pacing is active, there is a longitudinal alignment (along the main axis of the LV) of the hemodynamic forces associated with intracardiac flow, as it occurs in a normal heart.…”