Accessory Left Atrial Diverticulae: Contractile Properties Depicted with 64-Slice Cine-Cardiac CT

OBJECTIVES: To assess the contractility of accessory left atrial appendages (LAAs) using multiphasic cardiac CT.

METHODS: We retrospectively analyzed the presence, location, size and contractile properties of accessory LAAs using multiphasic cardiac 64-slice CT in 102 consecutive patients (63 males, 39 females, mean age 57). Multiplanar reformats were used to create image planes in axial oblique, sagittal oblique and coronal oblique planes. For all appendages with an orifice diameter >10 mm, axial and sagittal diameters and appendage volumes were recorded in atrial diastole and systole. Regression analysis was performed to assess which imaging appearances best predicted accessory appendage contractility.

RESULTS: Twenty-three (23%) patients demonstrated an accessory LAA, all identified along the anterior LA wall. Dimensions for axial oblique (AOD) and sagittal oblique (SOD) diameters and sagittal oblique length (SOL) were 6.3-19, 3.4-20 and 5-21 mm, respectively. All appendages (>10 mm) demonstrated significant contraction during atrial systole (greatest diameter reduction was AOD [3.8 mm, 27%]). Significant correlations were noted between AOD-contraction and AOD (R = 0.57, P < 0.05) and SOD-contraction and AOD, SOD and SOL (R = 0.6, P < 0.05). Mean diverticulum volume in atrial diastole was 468.4 +/- 493 mm(3) and in systole was 171.2 +/- 122 mm(3), indicating a mean change in volume of 297.2 +/- 390 mm(3), P < 0.0001. Stepwise multiple regression analysis revealed SOL to be the strongest independent predictor of appendage contractility (R(2) = 0.86, P < 0.0001) followed by SOD (R(2) = 0.91, P < 0.0001).

CONCLUSIONS: Accessory LAAs show significant contractile properties on cardiac CT. Those accessory LAAs with a large sagittal height or depth should be evaluated for contractile properties, and if present should be examined for ectopic activity during electrophysiological studies.

PMID: 19768571

Posted in Computed Tomography and tagged , .


  1. Also check other recent related publications:

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    Abbara S, Mundo-Sagardia JA, Hoffmann U, Cury RC.
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    – Endocardial irregularities of the left atrial roof as seen on coronary CT angiography.
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  2. Interesting information! However, with only a single case reported of a thrombus within an accessory appendage, and very little data to support the authors suggestion of diverticula as a source of ectopic activity; the real significance of this findings still needs to be investigated.

  3. see newer manuscript:

    Presence of accessory left atrial appendage/diverticula in a population with atrial fibrillation compared with those in sinus rhythm: a retrospective review.
    Troupis J, Crossett M, Scneider-Kolsky M, Nandurkar D.
    Int J Cardiovasc Imaging. 2011 Feb 18.
    PMID: 21331611

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