Clinical Utility of Left Atrial Asynchrony and Mechanical Function in Patients with Hypertrophic Cardiomyopathy.

Background: The aim of this study was to examine whether left atrial dispersion and left atrial strain as measured by speckle tracking echocardiography and clinical parameters are predictors of the development of atrial fibrillation in patients with hypertrophic cardiomyopathy. Methods: A total of 151 patients (69% male, mean age 48.9 +/- 14.2 years) with hypertrophic cardiomyopathy were included in the study. The patients' demographic, clinical, electrocardiographic, 2-dimensional classic and speckle tracking echocardiographic data were collected. Atrial fibrillation was identified by 12-lead electrocardiograms or 24-72 hours of Holter recordings during the follow-up period. Atrial dispersion was defined as the standard deviation of time to peak strain in 12 left atrial segments. Results: During the follow-up period, 40 patients (26%) developed atrial fibrillation. Peak atrial longitudinal strain (16.8 +/- 6 vs, 22.1 +/- 6.6, p <= 0.001) was significantly lower in the patients who developed atrial fibrillation than in those who did not. However, atrial dispersion was significantly higher in the group which developed atrial fibrillation (61 [46.7,78.6] vs. 41.3 [30.6-51], p <= 0.001). In multivariate Cox regression analysis, atrial dispersion (msn) (hazard ratio: 1.019, 95% confidence interval: 1.004-1.033, p = 0.01), peak atrial longitudinal strain, and age were found to be independent predictors of atrial fibrillation. Conclusions: In patients with hypertrophic cardiomyopathy, atrial dispersion, peak atrial longitudinal strain and age are predictive of the development of atrial fibrillation. Atrial dispersion measured by a speckle tracking-based method may provide further information on left atrial function in patients with hypertrophic cardiomyopathy or other disease states.