Usefulness of pulsed-wave tissue Doppler imaging at the mitral annulus for prediction of new-onset atrial fibrillation in dogs.

INTRODUCTION

The time from the onset of the P wave on electrocardiogram to the peak of late diastolic wave signal (PA-TDI interval) recorded by left atrial pulsed-wave tissue Doppler imaging (PW-TDI) is a surrogate of the total atrial conduction time, and it can predict the development of new-onset atrial fibrillation (AF) in people. This study investigated whether PA-TDI interval measured with PW-TDI at the level of lateral aspect of the mitral valve annulus could identify dogs which developed AF within 6 months after echocardiography.

ANIMALS: Forty-two dogs with different cardiac diseases were included; 21 dogs developed AF within 6 months after echocardiography (AF group) and 21 dogs did not (non-AF group). Each AF case was matched with a non-AF case for body weight and left atrium:aortic root ratio.

METHODS

This was a retrospective study. Review of signalment, underlying disease and echocardiography data were included. PA-TDI interval was measured offline from acquired PW-TDI images. PA-TDI interval and standard echocardiographic variables were compared between groups. Receiver operator characteristic curves were used to identify the best AF predictor. Univariate and multivariate regression were used to evaluate predictors of PA-TDI interval.

RESULTS

The AF group had significantly greater 2D left atrial maximal diameter, left-ventricular (LV) end-diastolic volume, M-Mode LV internal diameter and LV end-systolic volume index. PA-TDI was significantly longer in the AF group, and it was superior to other echocardiographic variables in predicting AF development within 6 months (AUC = 0.896).

CONCLUSIONS

PA-TDI interval measured with PW-TDI at the lateral mitral valve annulus may identify dogs at risk of developing AF.