Prevalence of left atrial appendage pseudothrombus filling defects in patients with atrial fibrillation undergoing coronary computed tomography angiography

Saremi, Farhood; Channual, Stephanie; Gurudevan, Swaminatha V.; Narula, Jagat; Abolhoda, Amir

doi:10.1016/j.jcct.2008.02.012

« Previous Next »Journal of Cardiovascular Computed Tomography
Volume 2, Issue 3 , Pages 164-171, May 2008

Prevalence of left atrial appendage pseudothrombus filling defects in patients with atrial fibrillation undergoing coronary computed tomography angiography

Farhood Saremi, MD
- Department of Radiological Sciences, University of California Irvine, UCI Medical Center, 101 The City Drive, Route 140, Orange, CA 92868-3298, USA
- Corresponding author.
Stephanie Channual, BS
- Department of Radiological Sciences, University of California Irvine, UCI Medical Center, 101 The City Drive, Route 140, Orange, CA 92868-3298, USA
Swaminatha V. Gurudevan, MD
- Department of Cardiology, University of California Irvine, UCI Medical Center, 101 The City Drive, Route 140, Orange, CA 92868-3298, USA
Jagat Narula, MD, PhD
- Department of Cardiology, University of California Irvine, UCI Medical Center, 101 The City Drive, Route 140, Orange, CA 92868-3298, USA
Amir Abolhoda, MD
- Department of Cardiothoracic Surgery, University of California Irvine, UCI Medical Center, 101 The City Drive, Route 140, Orange, CA 92868-3298, USA

Received 22 August 2007; accepted 27 February 2008. published online 05 March 2008.

Abstract

Background

Previous reports have shown that computed tomography (CT) is a useful, noninvasive test for detecting atrial thrombi. However, blood stasis in the left atrial appendage (LAA) of patients with atrial fibrillation (AF) may be a common cause for false-positive results.

Objectives

We retrospectively evaluated the prevalence of filling defects that may simulate thrombus in the LAA of patients with AF during routine coronary CT angiography (CTA).

Methods

The LAA of 7 patients with AF was studied for the presence of filling defects and compared with 250 healthy persons. LAA volume in the patients with AF was measured at 10 different cardiac phases and compared with 30 healthy patients.

Results

Of the 7 patients with AF studied with CTA, 5 were positive for LAA filling defects. Follow-up imaging studies, including transesophageal echocardiogram, contrast-enhanced magnetic resonance angiography, or delayed-CT, were negative for LAA thrombus. Of 250 patients without AF, CTA showed no evidence of LAA filling defects. Patients with AF had significantly larger LAA volumes at all cardiac phases measured compared with patients without AF (15.2 ± 6.93 mL compared with 6.85 ± 3.01 mL at atrial contraction [P = 0.0187], 17.4 ± 7.76 mL compared with 9.46 ± 3.43 mL at ventricular systole [P = 0.0351], and 14.5 ± 5.87 mL compared with 8.48 ± 3.10 mL at mid-diastole [P = 0.0341]). Compared with the healthy persons, the patients with AF showed reduced percentages of change in LAA volume when the atrial contraction phase was compared with other phases: 44.0% ± 25.6% compared with 16.5% ± 12.2% compared with ventricular systole (P = 0.0004) and 29.5% ± 23.7% compared with −1.63% ± 8.84% at mid-diastole (P < 0.0001).