Left Atrial Size--another Differentiator for Cardiac Amyloidosis

Background: The "sparkled" echocardiographic appearance of amyloid has become less visually obvious in the era of harmonic imaging. Significantly dilated atria in the setting of a normal sized ventricle may be another easy visual marker for cardiac amyloidosis.

Methods: A retrospective analysis of echocardiograms of patients with biopsy-proven cardiac amyloid compared with patients with hypertension was conducted. There were 36 patients in each group, and they were matched for left ventricular wall thickness, as well as age and sex.

Results: Patients with cardiac amyloid had significantly larger atria than the group with hypertension (left atrial areas 29 cm(2) versus 19 cm(2), p<0.001, AUC 0.84, volumes 100 cm(3) versus 55 cm(3), p<0.001, AUC 0.915). A volume of 69 cm(3) produced a specificity and sensitivity of 85% for amyloidosis.

Conclusions: Atrial dilatation can be used as a visual marker for cardiac amyloidosis. This may be a simple visual method to differentiate this infiltrative cardiomyopathy from left ventricular hypertrophy.