Abstract 10834: Noninvasive Quantification of Left Ventricular Elastance and Ventricular-Arterial Coupling Using Three-Dimensional Echocardiography and Arterial Tonometry
Background: Techniques previously used to assess left ventricular (LV) elastance (Ees) and ventricular-arterial coupling (CLV-A) relied on invasive measurements and data acquisition over a wide range of loading conditions. Our goals were to assess the feasibility of noninvasive assessment of Ees and CLV-A using the combination of real-time three-dimensional echocardiography (RT3DE) and arterial tonometry, to test the ability of this approach to detect changes in LV contractility and its reproducibility.
Methods: We studied pharmacologically induced changes in inotropic state (10 µg/kg/min dobutamine) in normal volunteers (N=8), and compared 10 normal subjects with 10 patients with dilated cardiomyopathy (DCM; EF<35%). Full-volume RT3DE images of the left ventricle, calibrated carotid artery tonometry and Doppler tracings were acquired to noninvasively estimate Ees and CLV-A. Reproducibility was assessed by repeated measurements.
Results: Dobutamine caused a significant increased blood pressure, heart rate, EF and Ees and a decreased CLV-A. In patients with DCM, Eeswas significantly reduced and CLV-A elevated, compared to controls. Both inter- and intra-observer variability were good for all measured parameters, as reflected by intra-class correlation coefficients (ICC >0.8) and coefficients of variation (CV<20%). Calculated Ees showed significant differences between DCM patients and controls, with no overlap and good reproducibility: inter-observer ICC 0.83, CV 20%.
Conclusions: This is the first study to test the feasibility of using RT3DE-derived instantaneous LV volumes in conjunction with arterial tonometry to noninvasively quantify LV elastance and LV-arterial coupling without the need to alter the loading conditions. This approach is reproducible and able to detect changes in LV contractility. Due to its noninvasive nature, it may have clinical implications in various disease states.
- © 2011 by American Heart Association, Inc.