Abstract 20018: Increased Blood Stasis in the LV of Patients With Atrial Fibrillation
Recent studies have shown that atrial stasis may not be the unique source of cardioembolism in patients with atrial fibrillation (AF). In the healthy left ventricle (LV), the intraventricular flow arrangement has been proposed to optimize blood mixing within the chamber. However, blood flow patterns in the LV are highly sensitive to the timing intervals of the cardiac cycle, being altered if active atrial contraction is lost. Thus, in patients with AF, impaired blood mixing may result in blood stasis and thrombogenesis in the LV. Our objective is to quantify LV stasis in paced ventricular rhythm (to avoid the confusion related to irregularity) in order to compare patients with AF and patients with sinus rhythm.
Two-dimensional flow velocity fields from color Doppler echocardiographic sequences were obtained in 21 patients with AF and VVI paced ventricular rhythm (AF-VVI) and in 21 patients in sinus rhythm (SR) with VDD paced ventricular rhythm (SR-VDD). Using the advection equation for the residence time (TR), functional stasis maps of blood after 8 beats were obtained and analyzed (See Figure).The AF-VVI group showed a significantly lower renewal-rate of blood inside the LV after 8 beats when compared to the SR-VVD group, presenting larger regions with high TR (0.37 ± 0.18% vs. 0.23 ± 0.16%, p = 0.011). These regions showed also higher contact-ratio with the LV wall (0.79 ± 0.22% vs. 0.61 ± 0.24% p = 0.016). The aggregate variable of those regions of high TR with large size and wall contact ratio as well as low kinetic energy and shear stress was also found worse in the AF-VVI (2·10-4 ± 2·10-4 mJ.s/m vs. 1·10-4 ± 1·10-4 mJ.s/m p = 0.037).
Conclusions: Intraventricular flow is impaired in patients in AF, generating less blood washing and areas of stasis within the LV. This distinct kinetics of blood in the LV may be an unreported source of thrombogenesis in AF. Noninvasive flow mapping is a promising tool for stratification of thromboembolic risk in patients with heart disease.
Author Disclosures: L. Real-Valdés: None. V. Antón de Zafra: None. P. Martinez-Legazpi: None. C. Pérez del Villar: None. L. Rossini: None. R. Yotti: None. Y. Benito: None. G. Loughlin: None. A. Delgado-Montero: None. F. Fernandez-Aviles: None. J. del Alamo: None. J. Bermejo: None.
- © 2016 by American Heart Association, Inc.