Left atrial maximum volume is a recurrence predictor in lone atrial fibrillation: an acoustic quantification study

Predictors of recurrence in lone atrial fibrillation have not been clearly identified. Acoustic quantification (AQ) is a promising method in the assessment of left atrial (LA) volumes. The purpose of the present study was to investigate the potential of LA volumes obtained by standard manual tracing and AQ methods in predicting AF-recurrence after restoring the sinus rhythm in patients with lone AF, and to test the agreement between the two approaches. Standard echocardiography combined with AQ was performed in 28 patients with lone AF one hour after the sinus rhythm was regained, and in 10 controls. LA volumes were determined by conventional manual tracing and AQ methods. AQ waveforms of LA were obtained by drawing a region of interest around the LA border. The agreement of the two methods was tested by Bland-Altman analysis. Patients were followed up for 6 months for the occurrence of AF recurrence. A good correlation was observed between AQ and manual tracing methods in determining both minimal (r=0.59) and maximal (r=0.88) LA volumes. Patients with AF recurrence had a significantly larger maximum LA volume as assessed with both methods (P<0.05 for both). M-mode derived LA dimension and isovolumic relaxation time were additional predictors of recurrence in patients with lone AF. In lone AF, patients prone to recurrence could be predicted by determining LA maximum volume assessed either by AQ or manual tracing methods. AQ provides on-line, accurate estimation of LA volumes.