Oral presentations

001 FLOW QUANTIFICATION: AN IN-VITRO AND IN-VIVO VALIDATION OF A RAPID, ACCURATE AND REPRODUCIBLE 3D ECHOCARDIOGRAPHIC TECHNIQUE

S. Kapetanakis, E. Ho, S. P. Turner, M. J. Monaghan.King’s College Hospital, London, UK

Introduction: Non-invasive quantification of blood flow by standard echocardiographic techniques is widely used for quantification of valvular disease and shunt size. However these methods are limited by geometric assumptions. Real-Time 3D Echo provides an alternative method for flow quantification.

Methods: For in-vitro quantification we developed a flow phantom with viscosity and backscatter properties similar to blood. 42 3D colour flow acquisitions were performed at a range of cardiac outputs (range: 1.8–5.5 L/min), at a range of different simulated heart rates (50–92 min-1) to calculate the cardiac output (CO). In-vivo quantification of flow was performed in 49 normal subjects to compare the CO at the mitral valve and left ventricular outflow tract. The same quantification was performed in 78 patients with mitral regurgitation and a 3D regurgitant fraction was derived. This was compared with the 2D area method and PISA calculations where possible.

Results: In all data sets, 3D CO was calculated in <45 sec. Cardiac output derived 3D flow quantification showed excellent correlation with pre-defined CO in the in-vitro model (R = 0.98, average difference 0.02 L/min with 95% CI −0.03 to + 0.07 L/min, n = 42). In normal subjects, there was excellent correlation between CO at the mitral and LVOT positions (R = 0.96 n = 49). 3D regurgitant fraction showed excellent correlation with the 2D area method (R = 0.88 n = 78). In patients with mitral regurgitation, PISA calculations were possible only in 18% and demonstrated only moderate correlation.

Conclusions: 3D flow quantification is a rapid and accurate technique which will be valuable in assessment of valvular regurgitation.

002 VARIABLE MECHANICAL CONTRACTION SEQUENCE IN LEFT BUNDLE BRANCH BLOCK ILLUSTRATED BY 3D ECHOCARDIOGRAPHIC CONTRACTION FRONT MAPPING, A NOVEL, HIGH RESOLUTION IMAGING TECHNIQUE

S. Kapetanakis, E. Ho, S. P. Turner, M. T. Kearney, M. J. Monaghan.King’s College Hospital, London, UK

Introduction: LV Mechanical Dyssynchrony (LVMD) has emerged as a therapeutic target in resynchronisation therapy (CRT). Real-Time 3D …