Abstract 21659: Left Atrial Strain and Strain Rate Imaging: Comparison Between Healthy Individuals and a Cohort at High Risk for First Atrial Fibrillation
Background: We have previously reported the left atrial (LA) speckle tracking (SpTr) strain and strain rates for normal healthy persons. We aimed to compare the strain and strain rates of normal persons to those at high risk for first atrial fibrillation (AF).
Methods: We invited normal healthy individuals from the community without any cardiovascular risk factors to participate. They had to have completely normal echocardiographic findings to be entered into the normal group. Their strain and strain rates were compared to a cohort of individuals at high risk for first AF (estimated risk of first AF about 10% over mean of 4.5 years), all age ≥65 years and had at least 2 other risk factors for first AF (hypertension, proven coronary artery disease, heart failure, diabetes). LA SpTr strain and strain rates were obtained through averaging the values from the 13 segments at 4 time points in the cardiac cycle. Data between two groups were compared using Student's T test, and again with age-adjustment.
Results: A total of 100 healthy volunteers (mean age 43 ± 12 years) and 61 high risk individuals (mean age 75 + 5 years) were included in the analyses. Table 1 shows the averaged strain and strain rates for the 13 segments at 4 time points, using Student t-tests. After age-adjustment, the differences between the 2 groups remained, although the magnitude of significance was slightly reduced. In the high risk cohort, the global LA SpTr strain was significantly reduced at peak ventricular systole (p<.00001) and the LA SpTr SR was decreased significantly at all 4 times points.
Conclusion: LA SpTr strain and strain rate imaging can discriminate normal individuals of low risk for any cardiovascular events from those at high clinical risk for AF. Further studies are necessary to determine the relative contribution of age and non-age cardiovascular risk factors to the observed differences, and the incremental value of strain and strain rates over clinical risk factors for the prediction of first AF..
- © 2010 by American Heart Association, Inc.