Strain and Strain Rate Imaging in Evaluating Left Atrial Appendage Function by Transesophageal Echocardiography
This study was planned to assess whether strain rate (Sr) and strain (S) echocardiography is a useful method for functional assessment of the left atrial appendage (LAA). Fifty-seven consecutive patients underwent a clinically indicated study. LAA late empty velocity (LAAEV) was calculated as a gold standard for left atrial appendage function. Real-time 2-dimensional color Doppler myocardial imaging data were recorded from the LAA at a high frame rate. Analysis was performed for LAA longitudinal strain rate and strain from midsegment of lateral wall of LAA. LAA strain determines regional lengthening expressed as a positive value or shortening expressed as a negative value. Peak systolic values were calculated from the extracted curve. Spearman correlation test results showed a statistically significant positive correlation was between the S, Sr variables and LAAEV (LAAEV vs S; r = 0.886, P < 0.001; LAAEV vs Sr: r = 0.897, P < 0.001, respectively). Strain and strain rate values were also significantly lower in patients with spontaneous echocardiographic contrast when compared with those without (strain; 2.42 +/- 0.98 vs 13.1 +/- 5.9, P < 0.001 and strain rate: 0.97 +/- 0.54 vs 3.34 +/- 1.15, P < 0.001, respectively). In addition, LAA strain and strain rate values were significantly lower in the patients with LAA thrombus (strain; 2.15 +/- 0.96 vs 8.35 +/- 6.9, P < 0.001, strain rate; 0.79 +/- 0.46 vs 2.30 +/- 1.48, P < 0.001, respectively). S and Sr imaging can be considered a robust technique for the assessment of the LAA systolic deformation.