Multislice Computed Tomography Accurately Quantifies Left Atrial Size and Function After the MAZE Procedure

Abstract

Background-Although the MAZE procedure allows for the recovery of sinus rhythm and left atrial (LA) mechanical function in the great majority of patients with chronic atrial fibrillation (AF), the effects of MAZE on the precise LA geometry and wall motion remain to be elucidated. We hypothesized that LA size and mechanical function in patients with chronic AF and mitral valvular disease are well restored after MAZE. In the CABG group, LA maximal and minimal volumes and ejection fraction were 109Ϯ12 mL, 82Ϯ11 mL, and 26Ϯ10%, respectively. In the MAZE group, LA maximal volume was 139Ϯ17 mL (Pϭ0.187 versus CABG), and LA minimal volume was 121Ϯ16 mL (Pϭ0.082 versus CABG), with an ejection fraction of 15Ϯ7% (Pϭ0.004 versus CABG). In both groups, all parts of the LA wall contracted toward the geometric center of the LA. The extent of wall motion was significantly worse in the MAZE group compared with the CABG group. In both groups, LA booster function was inversely correlated with LA maximal volume. Conclusions-MAZE

A new method for measurement of left atrial volumes using 64-slice spiral computed tomography: Comparison with two-dimensional echocardiographic techniques

“…By TTE the image quality is often affected by acoustic shadowing in one or more views. The maximal non-indexed LA volume of our patients (125 ± 40 ml) is in accordance with previous published reports [30,31]. Before a MAZE procedure the LAmax was found 139 ± 17 ml in a study performed using a 16-MSCT scanner [30].…”

Adjusted Left Atrial Emptying Fraction as a Predictor of Procedural Outcome after Catheter Ablation for Atrial Fibrillation

“…However, our group previously showed that LAVs and LAEF deter mined by means of TTE correlated well with those de termined by means of 10phase analysis with MSCT, even when AF was the underlying rhythm. 6 In addition, previous investigators have shown that MSCT has ex cellent spatial and temporal resolution, and the LAV can be accurately quantified by using the modified Simpson method, 9 which enables the evaluation of LAEF with use of volumetric data and reflects global contractility with excellent reproducibility. 10 It is unclear whether LA enlargement leads to re current AF directly or whether it is a consequence of AF.…”

Left atrial appendage contributes to left atrial booster function after the maze procedure: quantitative assessment with multidetector computed tomography☆

“…Since LA wall motion is globally disturbed in patients with chronic AF and MVD [5,6], LAA preservation appears to play an important role in LV filling [11][12][13][14]. By contrast, since LA wall motion in patients with CABG is relatively well maintained, LAA excision and/or occlusion may be well tolerated in terms of LV filling.…”

“…LA function improves by the removal of the poor wall motion area such as the posterior wall. Since the regional wall motion of LA is not uniform [5], it appears to be important to remove only the poor wall motion area and to preserve the good wall motion area (e.g., LAA).…”

“…LAA exclusion was also reported to reduce embolic risk in patients with the maze procedure [4]. On the other hand, we have recently reported that left atrial (LA) booster function in patients with the maze procedure for chronic AF and mitral valve disease (MVD) is markedly reduced [5]. In these patients, LAA booster function may compensate for the impaired LA booster function.…”