Session P95.5

Assessing the Wall Motion of Pulmonary Veins of the Left Atrium

WC Hu*, JJ Wang, HM Tsao, LY Shyu

Chung Yuan Christian University
Chung Li, Taiwan

It was hypothesized that the electrical activity arising from myocardial sleeve of pulmonary veins (PV) can trigger AF. The treatment for AF patient normally underwent ablation to block the electrical conduction pathway to minimize the extra electrical activity. The return of regularly atrial function can be evaluated using cardio images. To assess the outcome of atrial ablation non-invasively is to determine the change of volume at the diastolic phase and the systolic phase of left atrium. However, the role of the sphincter function of these fibers in generation of AF remains to be elucidated. This abstract is to report the development of 4D cardio-images analysis system that successfully assesses atrial volume and wall motion of pulmonary veins using multi-Slice CT (MSCT) cardiac images non-invasively. The procedure of the program will be, first, aligning the 3D CT images dataset, then, reconstructing the 3D volume of heart. A cut plane method is utilized to accurately delineate the 4 pulmonary veins and set the boundary at mitral valve for the left atrial contour extraction. The delineated information can be mapped onto the original CT images. The method of active contouring and seed region growth were implemented in the program for 3D atrial segmentation. The contour information will be re-sampled for the reconstruction of wire-mesh display. In result, the MSCT cardiac images of eleven AF patients (11 patients) and eight control patients (8 patients without AF) was acquired at 30% and 90% of RR interval. The left atrial volume, the atrial Ejection Fraction (EF), the dimension and the wall motion of PVs were evaluated. The result also shows that patient with AF, the ejection function is much lower than the control group (30.81 ± 13.61% vs 36.69 ± 19.95%, p < 0.05). The dimension of the pulmonary veins shows that the two superior veins are larger than the two inferior veins (LSPV: 2.76 ± 1.33mm2, RSPV: 2.58 ± 1.21mm2, LIPV:1.74 ± 1.14mm2, RIPV: 1.97 ± 0.84mm2, p < 0.05). For the patients with AF, the wall motion of posterior and lower side of right inferior pulmonary vein was showing significantly less activity than others (p < 0.01).

(Abstract Control Number: 273)