Quantitative description of the regional mechanics of the left atria by electroanatomical mapping.

The left atrium is a complex chamber, which plays an integral role in the maintenance of physiologic hemodynamic and electrical stability of the heart and is involved in many disease states, most commonly atrial fibrillation. Preserving regions of the left atrium that contribute the greatest to atrial mechanical function during curative strategies for atrial fibrillation are important. We present here a new application of the CARTO electroanatomical mapping system in the assessment of the left atria mechanical function. Electroanatomical data were collected in course of the electrophysiological procedure in 11 control patients and 12 patients with paroxysmal atrial fibrillation. The three-dimensional geometry of the left atria was reconstructed in 10 ms intervals and segmented into distinct regions. For each segment, a regional ejection fraction was calculated. We found that anterior, septal and lateral segments have significantly greater regional ejection fraction than atria roof, inferior and posterior segments. Therefore, we hypothesize that in order to minimize the impact on atrial mechanical function, an important determinant of thromboembolic risk, damage should be minimized to these atrial regions.