Association of Decreased Left Atrial Strain and Strain Rate with Stroke in Chronic Atrial Fibrillation Jhih-Yuan Shih, MD, Wei-Chuan Tsai, MD, Yao-Yi Huang, MD, Yen-Wen Liu, MD, Chih-Chan Lin, MD, Yu-Shan Huang, MD, Liang-Miin Tsai, MD, and Li-Jen Lin, MD, Tainan and Dou-Liou, Taiwan Background: The objective of this study was to investigate myocardial deformation of the left atrium (LA) as- sessed by two-dimensional speckle tracking echocardiography in patients with permanent atrial fibrillation (AF) and its value for risk stratification for stroke. Methods: We recruited 66 consecutive patients with permanent AF who were referred to our echocardiogra- phy laboratory for evaluation. These patients were divided into two groups according to the presence of pre- vious stroke or not. Results: Peak positive longitudinal strain (LASp) during atrial filling, peak strain rate in the reservoir phase of LA (LASRr), and peak strain rate in the conduit phase (LASRc) were identified from LA strain and strain rate curves. The ratio of peak early filling velocity (E) of mitral inflow to early diastolic annulus velocity (E’) of the medial annulus (E/E’) was calculated. LASp (10.44% 6 4.2% vs. 15.69% 6 5.1%, P<.001), LASRr (1.09 6 0.27 1/s vs. 1.37 6 0.32 1/s, P = .001), and LASRc (À1.28 6 0.38 1/s vs. À1.62 6 0.43 1/s, P = .002) were significantly lower in pa- tients with AF with stroke than those without stroke. By multivariate analysis controlling for age, LA volume index, and left ventricular ejection fraction, LASp (OR 0.787, 95% CI, 0.639–0.968, P = .023) and LASRr (OR 0.019, 95% CI, 0.001–0.585, P = .023) were independently associated with stroke but not LASRc, E’, and E/E’ ratio. Conclusion: Decreased LASp and LASRr were independently associated with stroke in patients with perma- nent AF. (J Am Soc Echocardiogr 2011;24:513-9.) Keywords: Atrial fibrillation, Left atria, Strain, Strain rate, Stroke Atrial fibrillation (AF) is the most common arrhythmia and increases risk of stroke and mortality from myocardial infarction and heart fail- ure. 1,2 The echocardiographic parameters associated with an elevated risk of embolism are increased left atrium (LA) dimension, 3 decreased LA appendage (LAA) flow velocity, and proof of thrombi or spontane- ous echo contrast during transesophageal echocardiography. 4-8 Although transesophageal echocardiography is a useful method for predicting stroke and deciding on anticoagulation therapy, it is a semi-invasive method and cannot be used as widely as transthoracic echocardiography. 9 A novel approach to quantify regional left ventric- ular (LV) function from routine gray-scale two-dimensional echocardio- graphic images, known as speckle tracking two-dimensional strain echocardiography, calculates myocardial strain independently of angle of incidence and has recently been validated against sonomicrometry and tagged magnetic resonance imaging. 10-13 Speckle tracking echocardiography has also been used for the assessment of LA function. 14,15 Our recent study showed that decreased LA strain and strain rate assessed by speckle tracking echocardiography were associated with paroxysmal AF. 16 The feasibility of two-dimensional speckle tracking echocardiography for measuring LA deformation in patients with paroxysmal and persistent AF was documented in a recent study, and the LA deformation was inversely related to LA wall fibrosis, as demonstrated by delayed enhancement on magnetic resonance im- aging. 17 The objective of this study was to investigate LA deformation assessed by two-dimensional speckle tracking echocardiography in pa- tients with permanent AF and its value for risk stratification for stroke. MATERIALS AND METHODS Study Population We recruited 79 consecutive patients with permanent AF who were re- ferred to our echocardiography laboratory for evaluation from June to November in 2009. Permanent AF was diagnosed according to the guidelines of the American College of Cardiology, the American Heart Association, and the European Society of Cardiology. 18 Patients with mitral stenosis (n = 3) and inadequate imaging (n = 10) were ex- cluded, and 66 patients were included. Patients were carefully evaluated for the presence of ischemic stroke. Stroke was defined by a history of hospital admission and positive image studies from brain computed to- mography. All study patients had ischemic stroke; patients with hemor- rhagic stroke were excluded. The stroke risk of our patients was assessed From the Tainan Hospital Sin-Hua Branch, Tainan, Taiwan (J-Y.S.); Department of Internal Medicine, National Cheng Kung University Medical Center, Tainan, Taiwan (W-C.T., Y-W.L., C-C.L., L-M.T., L-J.L.); Department of Internal Medicine, National Cheng Kung University Hospital Dou-Liou Branch, Dou-Liou, Taiwan (Y-Y.H.); and Department of Internal Medicine, Tainan Hospital, Tainan, Taiwan (Y-S.H.). This study was supported by Grants NSC 97-2314-B-006-054 and NSC 98-2314- B-006-051 from the National Science Council, Executive Yuan, Taipei, Taiwan. Reprint requests: Wei-Chuan Tsai, MD, Associate Professor of Medicine, National Cheng Kung University Medical Center, 138 Sheng-Li Road, Tainan 704, Taiwan (E-mail: wctsai@ksmail.seed.net.tw). 0894-7317/$36.00 Copyright 2011 by the American Society of Echocardiography. doi:10.1016/j.echo.2011.01.016 513