Noninvasive estimation of the rate of relaxation by the analysis of intraventricular pressure gradients.

Background: During late ejection, myocardial relaxation causes systolic flow to decelerate and stop, and this phenomenon is coupled with the generation of a pressure gradient inside the left ventricle (LV). We hypothesized that the peak reverse ejection intraventricular pressure difference (REIVPD) between the LV apex and the outflow tract could be a useful method to improve the assessment of LV relaxation using Doppler echocardiography.

Methods And Results: Three sets of animal experiments and 1 clinical study were designed.

Two-dimensional intraventricular flow mapping by digital processing conventional color-Doppler echocardiography images.

Doppler echocardiography remains the most extended clinical modality for the evaluation of left ventricular (LV) function. Current Doppler ultrasound methods, however, are limited to the representation of a single flow velocity component. We thus developed a novel technique to construct 2D time-resolved (2D+t) LV velocity fields from conventional transthoracic clinical acquisitions.

Noninvasive assessment of the right ventricular filling pressure gradient.

Background: The physiological basis of right ventricular (RV) diastolic function remains incompletely studied in humans. The driving force responsible for RV filling, the pressure gradient along the RV inlet from the right atrium to the RV apex, has never been measured in the clinical setting.

Methods And Results: We validated a method for measuring the RV filling pressure difference (RVFPD) from color Doppler M-mode recordings in 12 pigs undergoing interventions on RV preload, afterload, and lusitropic states (error, -0.

A noninvasive method for assessing impaired diastolic suction in patients with dilated cardiomyopathy.

Background: Diastolic suction is a major determinant of early left ventricular filling in animal experiments. However, suction remains incompletely characterized in the clinical setting.

Methods And Results: First, we validated a method for measuring the spatio-temporal distributions of diastolic intraventricular pressure gradients and differences (DIVPDs) by digital processing color Doppler M-mode recordings.

Doppler-derived ejection intraventricular pressure gradients provide a reliable assessment of left ventricular systolic chamber function.

Background: Ejection intraventricular pressure gradients are caused by the systolic force developed by the left ventricle (LV). By postprocessing color Doppler M-mode (CDMM) images, we can measure noninvasively the ejection intraventricular pressure difference (EIVPD) between the LV apex and the outflow tract. This study was designed to assess the value of Doppler-derived EIVPDs as noninvasive indices of systolic chamber function.