Turk Kardiyol Dern Ars 2016;44(1):45-52 doi: 10.5543/tkda.2015.11354 Predictive role of left atrial and ventricular mechanical function in postoperative atrial fibrillation: a two-dimensional speckle-tracking echocardiography study Ameliyat sonrası atriyum fibrilasyonunu öngörmede sol atriyum ve ventrikülün mekanik fonksiyonlarının rolü: İki boyutlu speckle-tracking ekokardiyografi çalışması Dept. of Cardiology, Muğla Sıtkı Koçman University Faculty of Medicine, Muğla, Turkey; #Dept. of Cardiology, Marmara University Faculty of Medicine, İstanbul, Turkey; *Dept. of Cardiology, Malatya State Hospital, Malatya, Turkey; †Dept. of Cardiology, Büyük Meydan Hospital, Samsun, Turkey; ‡Dept. of Cardiology, Kartal Koşuyolu Heart Training and Research Hospital, İstanbul, Turkey; §Dept. of Cardiology, Elazığ Training and Research Hospital, Elazığ, Turkey; ||Dept. of Cardiology, Acıbadem University Faculty of Medicine, İstanbul, Turkey Özcan Başaran, M.D., Kürşat Tigen, M.D.,# Gökhan Gözübüyük, M.D.,* Cihan Dündar, M.D.,† Ahmet Güler, M.D.,‡ Onur Taşar, M.D.,§ Murat Biteker, M.D., Can Yücel Karabay, M.D.,‡ Mustafa Bulut, M.D.,‡ Tansu Karaahmet, M.D.,|| Cevat Kırma, M.D.‡ Objective: The aim of this study was to determine the role of left- sided mechanical parameters in postoperative atrial fibrillation (POAF) in patients undergoing coronary artery bypass grafting (CABG). Methods: Ninety patients with coronary artery disease and normal left ventricular (LV) function in sinus rhythm were enrolled in the study. Preoperative LV and left atrial (LA) mechanics were evalu- ated by two-dimensional (2D) speckle-tracking echocardiography (STE), including strain and rotation parameters, and volume indi- ces. Patients were monitored in order to detect POAF during the postoperative period. Results: Twenty-three of 90 patients (25.6%) developed POAF. Age (p<0.001) and preoperative beta blocker usage (p=0.001) were the clinical parameters associated with POAF. Left atrial maximum volume index (LAV[max]i) increased, and peak left atrial longitudinal strain (PALS) was impaired in POAF patients (p=0.001, p<0.001, respectively). Left ventricular twist (LVtw) and left ven- tricular peak untwisting velocity (UntwV) were augmented in POAF patients (p=0.013, p=0.009, respectively). Receiver operating char- acteristic analysis showed N-terminal pro-brain natriuretic peptide (NT-proBNP) levels above 70 pg/ml and predicted POAF with a sensitivity of 74% and specificity of 78% (area under curve: 0.758, 95% confidence interval [CI] 0.631–0.894, p<0.001). Logistic re- gression analysis demonstrated that age (odds ratio [OR] 1.1, CI 1.01–1.20, p=0.034), preoperative beta blocker usage (OR 8.84, CI 1.36–57.28, p=0.022), NT-proBNP (values >70 pg/ml, OR 22.377, CI 3.286–152.381, p<0.001), PALS (OR 0.86, CI 0.75–0.98, p=0.023), and UntwV (OR 1.02, CI 1.00–1.04, p=0.029) were the independent predictors of POAF. Conclusion: The combination of 2D STE, clinical, and biochemical parameters may help predict POAF. Amaç: Bu çalışmada koroner arter baypas cerrahisi (KABG) uy- gulanacak hastalarda, ameliyat sonrası atriyum fibrilasyonu (AF) gelişmesini öngörmede sol kalbe ait mekanik parametrelerin rolünü değerlendirmeyi planladık. Yöntemler: Çalışmaya koroner arter hastalığı olan, normal sol ventrikül sistolik fonksiyonuna sahip, sinüs ritminde 90 hasta alındı. Hastaların ameliyat öncesi sol atriyum ve sol ventrikülün mekanik fonksiyonları (strain, rotasyonal parametreler ve hacim indeksleri) iki boyutlu speckle-tracking ekokardiyografisi ile değerlendirildi. Hastalar ameliyat sonrası dönemde AF gelişimini değerlendirmek için monitorize edildiler. Bulgular: Doksan hastanın 23’ünde (%25.6) AF gelişti. Yaş (p<0.001), ameliyat öncesi beta bloker kullanımı (p<0.001) AF ile ilişkili klinik parametreler olarak saptandı. Sol atriyum hacim in- deksi AF gelişen hastalarda artmış olarak bulundu (p<0.001). Sol atriyumun strain (SAS) değerleri ise AF gelişen hastalarda azalmış olarak bulundu (p<0.001). Sol ventrikül twist ve pik untwisting hız (PUH) ise artmış olarak saptandı (sırasıyla, p=0.013 ve p=0.009). ROC analizinde 70 pg/ml üzerindeki NT-proBNP düzeylerinin AF’yi %74 duyarlılık ve %78 özgüllük (AUC: 0.758, %95 GA=0.631– 0.894, p<0.001) ile gösterdiği bulundu. Lojistik regresyon analizi sonucunda yaş (her bir yıllık artış OO: 1.133 GA: 1.029–1.247 p=0.011), beta bloker kullanımı (kullanmayanlarda kullananlara göre OO: 18.558 GA: 2.098-164.145 p=0.009), NT-proBNP (70 pg/ ml üzerindeki değerler altındakilere göre OO: 22.377 GA: 3.286– 152.381 p<0.001), SAS (OO: 0.839 GA: 0.730-0.963 p=0.013) ve PUH (OO: 1.032 GA: 1.009–1.055 p=0.005) AF için bağımsız de- ğişkenler olarak saptandı. Sonuç: İki boyutlu speckle-tracking ekokardiyografisi, klinik ve la- baratuvar verilerin birlikte kullanımı ameliyat sonrası atriyum fibri- lasyonu gelişiminin öngörülmesinde yardımcı olur. Received: February 25, 2015 Accepted: June 29, 2015 Correspondence: Dr. Özcan Başaran. Muğla Sıtkı Koçman Üniversitesi Tıp Fakültesi, Kardiyoloji Anabilim Dalı, Muğla. Tel: +90 252 - 214 13 26 e-mail: basaran_ozcan@yahoo.com © 2016 Turkish Society of Cardiology 45 ABSTRACT ÖZET Postoperative atrial fibrillation (POAF) is a risk factor for short-term morbidity and decreased long-term survival.[1] The incidence of POAF after isolated coronary artery bypass graft surgery (CABG) may be as high as 30%.[2] Furthermore, the occur- rence of POAF increases when the patient has 1 or more cardiovascular risk factors.[3] POAF has 2 major pathophysiological mechanisms: degenerative chang- es in atrial myocardium and preoperative electrophys- iological changes. Atria with preoperative mechanical dysfunction may develop atrial fibrillation (AF) dur- ing surgery. Enlarged left atrium and poor left atrial (LA) mechanical functions have been found to be pre- dictors of POAF.[4] Impaired left ventricular (LV) mechanical func- tion assessed by echocardiography (LV ejection frac- tion) was associated with POAF.[5] However, the role of subclinical LV mechanical function assessed by two-dimensional (2D) speckle-tracking imaging is less clear. Lower values of LV global longitudinal strain, measured by speckle-tracking echocardiogra- phy (STE), were associated with POAF in patients with aortic stenosis.[6] LV diastolic dysfunction is an- other risk factor for developing POAF.[7] LV rotational mechanics such as torsion, twist, and untwisting rate have not yet been investigated. There is a correlation between LV diastolic dysfunction, LA pressure, high B-type natriuretic peptide (BNP) levels and recur- rence of AF.[8,9] The aim of this study was to evaluate the associa- tion between POAF, LA and LV mechanical functions, and natriuretic peptides in patients having CABG. METHODS A prospective study was performed in 90 patients at- tending Kartal Koşuyolu Education and Research Hos- pital for CABG between March 2009 and December 2010. All included patients were in sinus rhythm and were without significant valvular disease. Exclusion criteria were thyroid function abnormality, chronic kidney disease, redo CABG, and a history of previous AF. Patients were monitored for 4 days in the inten- sive care unit and step-down unit. Postoperatively, 12 lead electrocardiograms were obtained daily. Postop- erative AF was defined as any episode of AF lasting at least 15 minutes.[5] The study population was divided into 2 groups according to POAF development. Blood samples were obtained the day before surgery to measure N-termi- nal pro-brain na- triuretic peptide ( N T- p r o B N P ) concentrations. The investiga- tion conformed to the principles out- lined in the Dec- laration of Hel- sinki. The study was approved by the local ethical committee. All participants gave written informed consent. Echocardiography Twenty-four hours before surgery, a baseline echo- cardiograph was obtained using conventional 2D echocardiography (Vivid 7, GE Vingmed Ultrasound AS, Horten, Norway) with a 3.5-MHz multiphase ar- ray probe in the left lateral decubitus position. Digital cineloop images were acquired from parasternal and apical views (standard parasternal short-axis from mid-ventricular level, apical long-axis, 2-chamber, and 4-chamber images). All examinations were per- formed by a single experienced cardiologist. Standard M-mode, 2D, and color coded tissue Doppler images were obtained and stored in cineloop format from 3 consecutive beats and transferred to a workstation for further offline analysis (EchoPAC 6.1, GE Vingmed Ultrasound AS, Horten, Norway). To optimize color saturation, the gain settings, filters, and pulse repeti- tive frequency were adjusted. A color Doppler frame scanning rate of 100–140 Hz was used for color tissue Doppler images. Cardiac dimensions were measured according to the guidelines of the American Society of Echocar- diography, and LV ejection fraction was calculated by biplane Simpson’s method.[10] Left atrial volume (LAV) was calculated from the apical 4- and 2-chamber views by area-length formula and indexed to the body surface area.[10] The left atrial minimum volume (LAV[min]) was measured at the ventricular end diastole, left atrial maximum volume Turk Kardiyol Dern Ars46 Abbreviations: 2D Two-dimensional AF Atrial fibrillation BNP B-type natriuretic peptide CABG Coronary artery bypass grafting CI Confidence interval LA Left atrial LAV Left atrial volume LAV(max) Left atrial maximum volume LAV(max)i Left atrial maximum volume index LAV(min) Left atrial minimum volume LV Left ventricular LVtw Left ventricle twist NT-proBNP N-terminal pro-brain natriuretic peptide OR Odds ratio PALS Peak LA longitudinal strain POAF Postoperative atrial fibrillation STE Speckle-tracking echocardiography UntwV Left ventricle peak untwisting velocity Predictive role of left atrial and ventricular mechanical function in postoperative atrial fibrillation 47 (LAV[max]) at the end systole, and LAV(p) at the atrial contraction (P wave on electrocardiogram).[11] The left atrial stroke fraction was calculated as (LAV[max]− LAV[min])÷LAV(max). The LA active emptying frac- tion was calculated as (LAV[p]−LAV[min])÷LAV(p). The LA passive emptying fraction was calculated as (LAV[max]−LAV[p])÷LAV(max). 2D STE LA-focused images, in apical 4-chamber view, were obtained for LA speckle-tracking analysis. A mini- mum frame rate of 40 frames/sec was required for reli- able operation of the program. For 2D speckle-track- ing strain analysis, a line was manually drawn along the LA endocardial contour of the apical 4-chamber view after contraction, when the LA was at its mini- mum volume, using the point-and-click approach.[12] The software automatically generated additional lines close to the atrial epicardium and mid-myocardial line, with the narrowest region of interest.[12] The region of interest included the entire LA myocardial wall, and a click feature increased or decreased the widths between endocardial and epicardial lines for thicker or thinner walls. Strain curves for each atrial segment were gen- erated, and peak LA longitudinal strain (PALS) was used for LA mechanical function (Figure 1a). Circumferential and longitudinal directional anal- ysis of LV strain was performed by 2D speckle-track- ing imaging technique.[13,14] Assessment of longitudinal peak systolic strain was performed by applying 2D speckle-tracking im- aging to the apical 2- and 4-chamber views of the LV. The LV was divided into 6 segments in each apical Figure 1. 2D STE (A) PALS (white arrow), (B) LVGLS (red circle), (C) LV basal and apical rotation (white arrows), (D) UntwV (red arrow). A C B D Turk Kardiyol Dern Ars48 Categorical variables were analyzed by chi-square test or Fisher’s exact test. A logistic regression model was used for determining POAF predictors. Receiver operating characteristic analysis was performed to find a cut-off value for prediction. A p value <0.05 was considered significant. RESULTS The clinical, demographic, and echocardiographic parameters of the patients are summarized in Table 1. Comparing non-POAF patients to POAF patients, age (58.7±10.1 years, 64.3±7.4 years, respectively, p<0.001), LAV(max)i (26.4±8.4 ml/m2, 34±11.3 ml/ m2, respectively, p<0.001), and NT-proBNP levels (56.0, 4.9153.2 pg/dl; 96.4, 10.0–195.0 pg/dl, respec- tively, p<0.001) were higher in POAF patients, while beta blocker usage (91%, 60%, respectively, p<0.001) was lower in POAF patients. Among 2D strain parameters, PALS was lower in AF patients than non-AF patients (24.2±5.8, 31.7±9.6, respectively, p<0.001). Left ventricular global longi- tudinal strain, left ventricular global radial strain, and left ventricular global circumferential strain values were not different between the 2 groups (-16.1°±3.9°, -14.8°±3.6°, respectively, p=0.188; -20.4°±7.9°, -20.2°±6.5°, respectively, p=0.926; 44.4°±7.6°, view. The values of LV global longitudinal strain were derived from the average value of the 6 segmental peak systolic longitudinal strain values (Figure 1b). Assessment of global radial strain and global cir- cumferential strain was performed by applying 2D speckle-tracking imaging to the parasternal short-axis views of the LV. The basal level, midventricular level, and apical short-axis of the LV were divided into 6 segments. The values of global radial strain and glob- al circumferential strain were derived from the aver- age of the 6 segmental peak systolic strain values. LV rotation parameters were assessed from para- sternal short axis views at the basal level (mitral valve) and at the apical level. LV basal rotation, LV apical rotation, LV twist (LVtw), and LV peak untwisting ve- locity (UntwV) were calculated (Figures 1c, d). LVtw was defined as the net difference between the LV rota- tion angles at the basal level and apical level. Statistical methods “SPSS for Windows 17.0” software (SPSS Inc., Chicago, IL, USA) was used for statistical analysis. Continuous variables were given as mean±SD, and categorical variables were given as percentages. Con- tinuous variables were analyzed by independent sam- ple t-test. Differences in the median values between groups were analyzed using Mann-Whitney U test. Table 1. Baseline demographic, clinical, and echocardiographic properties Variable Non-POAF (n=67) POAF (n=23) p Age (years) 58.7±10.1 64.3±7.4 <0.001 Gender (male %) 82 69 0.241 Hypertension (%) 37 43 0.601 Diabetes mellitus (%) 25 26 0.946 Beta blocker usage (%) 91 60 <0.001 BNP median, range (pg/dl) 56.0, (4.9–153.2) 96.4, (10.0–195.0) <0.001 LVEF (%) median, range 63.0, (50.1–72.2) 62.0, (55.4–70.5) 0.978 LAV(max)i (ml/m2) 26.4±8.4 34±11.3 <0.001 LAV(min)i (ml/m2) 11.9±4.8 15.8±6.3 0.003 LAV(p)i (ml/m2) 19.8±7.0 25.9±9.7 0.002 LA stroke F (%) 55.7±10.6 53.6±8.0 0.386 LA active emptying F (%) 40.3±12.0 38.6±10.0 0.618 LA passive emptying F (%) 25.6±11.5 24.1±9.3 0.558 POAF: Postoperative atrial fibrillation; BNP: Preoperative N-terminal pro-brain natriuretic peptide; LVEF: Left ventricular ejection fraction; LAV(max) i: Left atrial maximal volume index; LAV(min)i: Left atrial minimum volume index; LAV(p)i: Left atrial precontraction volume index; LA stroke F: Left atrial stroke fraction; LA active emptying F: Left atrial active emptying fraction; LA passive emptying F: Left atrial active emptying fraction. P values are given for the differences between non-POAF and POAF. 44.8°±6.3°, respectively, p=0.549). LVtw and UntwV were significantly lower in AF patients than in non- AF patients (16.3°±5.6°, 20.5°±8.1°, respectively, p=0.009; -122.9°/sec±38.0°/sec, -147.7°/sec±43.8°/ sec, respectively, p=0.013) (Figure 2). Receiver operating characteristic analysis was performed, and NT-proBNP level above 70 pg/ ml predicted POAF with a sensitivity of 74% and specificity of 78% (area under curve=0.758, 95% CI 0.631–0.894, p<0.001). Univariate logistic regression Predictive role of left atrial and ventricular mechanical function in postoperative atrial fibrillation 49 Table 2. Logistic regression model Univariate Multivariate p OR 95% CI p OR 95% CI Age (every 1 year increase) 0.003 1.085 1.028–1.146 0.011 1.133 1.029–1.247 Non-beta blocker usage 0.002 6.536 1.998–21.378 0.009 18.558 2.098–164.145 NT-proBNP <0.001 9.822 3.290–29.322 0.001 22.377 3.286–152.381 LAV(max)i 0.003 1.087 1.030–1.148 0.212 1.064 0.965–1.172 PALS (every 1% increase) 0.002 0.874 0.804–0.950 0.013 0.839 0.730–0.963 UntwV 0.002 1.022 1.008–1.037 0.005 1.032 1.009–1.055 LVtw 0.028 0.915 0.845–0.991 0.353 0.934 0.810–1.078 POAF: Postoperative atrial fibrillation; NT-proBNP: N-terminal pro-brain natriuretic peptide; LAV(max)i: Left atrial maximum volume index; LASs: Left atrial peak strain; UntwV: Left ventricular peak untwisting velocity; LVtw: Left ventricular twist; OR: Odds ratio; CI: Confidence interval. Bold figures indicate independent predictors of POAF. 60.00 50.00 .00 .00 .00 10.00 Absent Present p=0.00921 AF 0.00 Tw is t -50.00 50.00 20.00 50.00 -200.00 -100.00 Absent Present p<0.013 AF U nt w V 10 70.00 60.00 50.00 .00 .00 20.00 10.00 Absent Present AF PA LS 60 17 14 200.00 150.00 100.00 50.00 0.00 Absent Present p=0.001 AF N T- pr oB N P 67 63 19 22 45 A C B D Figure 2. (A-D) LVtw, untwisting velocity, PALS, and NT-proBNP values of POAF and non-POAF patients. Turk Kardiyol Dern Ars50 ment in patients with paroxysmal AF.[24] LA strain was also associated with AF recurrence after AF ablation procedures.[25] Previous studies have shown a predic- tive value of LA strain in POAF.[26–29] In our study, PALS, LAV, and volume indices were all associated with POAF development. However, in contrast to previous studies, the LA functions assessed by vol- ume index had no effect on POAF.[30] Moreover, the multivariate logistic regression analysis revealed that PALS acts as an independent risk factor. STE is a new and promising tool for the evaluation of myocardial function.[31] LV mechanical dysfunc- tion was shown to be an independent risk factor for POAF development in patients with aortic stenosis.[6] However, we were not able to show an impact of LV longitudinal strain assessed by STE on POAF devel- opment. LV untwisting velocity is a good indicator of LV active relaxation, making it an important marker of isovolumic relaxation.[32] LVtw and UntwV were sig- nificantly lower in POAF patients (p=0.009, p=0.013, respectively). Untwisting velocity was also an inde- pendent predictor of POAF development (every 1°/ sec increase: OR 1.032, CI 1.009–1.055, p=0.005). The difference in ventricular twist suggests a dys- function in subepicardial fibers, while maintenance of longitudinal strain may be associated with spared subendocardial fiber function. Early dysfunction in subepicardial fibers may be related with POAF. Our study demonstrates impaired LV rotational dynamics, but no longitudinal strain was associated with POAF development. BNP is a good surrogate of LV systolic and diastol- ic functions. It has been found to be an independent predictor of LV filling pressure.[33] Increased BNP and NT-proBNP levels were associated with AF after tho- racic and cardiac surgery.[19,34,35] Similar to previous studies, our study demonstrated that high plasma NT- proBNP levels were associated with a higher risk of developing POAF. In addition, we showed that im- paired LA strain, LV untwisting velocity, advanced age, high plasma NT-proBNP levels, and beta blocker usage were independent risk factors for developing POAF. Limitations This is a limited single-center study. Prospective large cohort studies are needed to evaluate the prognostic value of LA strain, LV twist, and NT-proBNP levels analysis showed an association among POAF and the following variables: age, beta blocker usage, NT- proBNP, LAV(max)i, PALS, LVtw, and UntwV. Mul- tivariate logistic regression analysis was performed to find independent predictors of POAF. Age (every 1 year increase: OR 1.133, CI 1.029–1.247, p=0.011), preoperative beta blocker usage (non-users to users: OR 18.558, CI 2.098–164.145, p=0.009), NT-proBNP (values >70 pg/ml: OR 22.377, CI 3.286–152.381, p<0.001), PALS (every 1% increase: OR 0.839, CI 0.730–0.963, p=0.013), and UntwV (every 1°/sec in- crease: OR 1.032, CI 1.009–1.055, p=0.005) were in- dependent risk factors for POAF (Table 2). DISCUSSION Our findings indicate that age, non-usage of beta blocker, NT-proBNP, LAV(max)i, and PALS are asso- ciated with POAF development. In addition, age, non- usage of beta blocker, NT-proBNP, PALS, and UntwV were found to be independent predictors of POAF. AF is the most common arrhythmia and complicat- ing factor in cardiac surgery, prolonging intensive care unit and total hospital stay.[3,15–18] Older age appears to be the most important clinical risk factor for devel- opment of POAF.[17,19] Aging causes cardiac structural changes such as fibrosis and cardiac myocyte enlarge- ment. Consequently, LV hypertrophy and decreased early-to-late diastolic filling ratio occur with aging.[20] Furthermore, aging was the major determinant of ear- ly-to-late ratio in the Framingham Heart Study.[21] As early diastolic filling rate decreases, late diastolic atri- al contraction increases in compensation, leading to atrial hypertrophy and enlargement. As a consequence of increased age and impaired LA functions, POAF might develop more frequently in older patients.[19] LA function is closely related with AF and can be estimated by LA volume measurements, Doppler analysis of transmitral and pulmonary venous flow, and by tissue Doppler echocardiography. While 2D LA volume measurements are affected by geometric assumptions, Doppler analysis is an indirect param- eter that is influenced by loading conditions. Tissue Doppler techniques are useful for the assessment of atrial function, but they are angle dependent.[22] Two- dimensional STE is a novel technique for detecting myocardial deformation.[23] In a recent study, LA strain was found to be impaired before LA enlarge- Predictive role of left atrial and ventricular mechanical function in postoperative atrial fibrillation 51 initiation of new-onset post-operative atrial fibrillation. J Am Coll Cardiol 2011;58:953–61. CrossRef 8. Machino-Ohtsuka T, Seo Y, Tada H, Ishizu T, Machino T, Ya- masaki H, et al. Left atrial stiffness relates to left ventricular diastolic dysfunction and recurrence after pulmonary vein isolation for atrial fibrillation. J Cardiovasc Electrophysiol 2011;22:999–1006. CrossRef 9. Ari H, Binici S, Ari S, Akkaya M, Koca V, Bozat T, et al. The predictive value of plasma brain natriuretic peptide for the recurrence of atrial fibrillation six months after external cardioversion. Turk Kardiyol Dern Ars 2008;36:456–60. 10. Lang RM, Bierig M, Devereux RB, Flachskampf FA, Foster E, Pellikka PA, et al. Recommendations for chamber quantifi- cation: a report from the American Society of Echocardiogra- phy’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr 2005;18:1440–63. CrossRef 11. Abhayaratna WP, Seward JB, Appleton CP, Douglas PS, Oh JK, Tajik AJ, et al. Left atrial size: physiologic determinants and clinical applications. J Am Coll Cardiol 2006;47:2357– 63. CrossRef 12. Her AY, Choi EY, Shim CY, Song BW, Lee S, Ha JW, et al. Prediction of left atrial fibrosis with speckle tracking echocar- diography in mitral valve disease: a comparative study with histopathology. Korean Circ J 2012;42:311–8. CrossRef 13. Delgado V, Ypenburg C, van Bommel RJ, Tops LF, Mol- lema SA, Marsan NA, et al. Assessment of left ventricular dyssynchrony by speckle tracking strain imaging compari- son between longitudinal, circumferential, and radial strain in cardiac resynchronization therapy. J Am Coll Cardiol 2008;51:1944–52. CrossRef 14. Donal E, Tournoux F, Leclercq C, De Place C, Solnon A, Derumeaux G, et al. Assessment of longitudinal and ra- dial ventricular dyssynchrony in ischemic and nonischemic chronic systolic heart failure: a two-dimensional echocardio- graphic speckle-tracking strain study. J Am Soc Echocardiogr 2008;21:58–65. CrossRef 15. Creswell LL, Schuessler RB, Rosenbloom M, Cox JL. Haz- ards of postoperative atrial arrhythmias. Ann Thorac Surg 1993;56:539–49. CrossRef 16. Andrews TC, Reimold SC, Berlin JA, Antman EM. Preven- tion of supraventricular arrhythmias after coronary artery bypass surgery. A meta-analysis of randomized control trials. Circulation 1991;84:III236–44. 17. Leitch JW, Thomson D, Baird DK, Harris PJ. The impor- tance of age as a predictor of atrial fibrillation and flutter after coronary artery bypass grafting. J Thorac Cardiovasc Surg 1990;100:338–42. 18. Crosby LH, Pifalo WB, Woll KR, Burkholder JA. Risk factors for atrial fibrillation after coronary artery bypass grafting. Am J Cardiol 1990;66:1520–2. CrossRef in POAF prediction. STE is a novel, easily applicable, and useful technique in the evaluation of myocardial function. However, it depends on the image quality, and the software was not primarily developed to eval- uate atrial strain and strain rate. Conclusion Postoperative AF is a major arrhythmia which com- plicates cardiac surgery. A combination of 2D STE, as well as clinical and biochemical parameters might help to predict the probability of a given patient de- veloping POAF. Funding The authors received no financial support for the re- search and/or authorship of this article. Conflict-of-interest issues regarding the authorship or article: None declared REFERENCES 1. Saxena A, Dinh DT, Smith JA, Shardey GC, Reid CM, New- comb AE. Usefulness of postoperative atrial fibrillation as an independent predictor for worse early and late outcomes after isolated coronary artery bypass grafting (multicenter Austra- lian study of 19,497 patients). Am J Cardiol 2012;109:219– 25. CrossRef 2. Mitchell LB. Incidence, timing and outcome of atrial tachyar- rhythmias after cardiac surgery. In: Steinberg JS, editor. Atrial fibrillation after cardiac surgery. Boston: Kluwer Academic Publishers; 2000. p. 37–50. CrossRef 3. Aranki SF, Shaw DP, Adams DH, Rizzo RJ, Couper GS, VanderVliet M, et al. Predictors of atrial fibrillation after cor- onary artery surgery. Current trends and impact on hospital resources. Circulation 1996;94:390–7. CrossRef 4. Gabrielli L, Corbalan R, Córdova S, Enríquez A, Mc Nab P, Verdejo HE, et al. Left atrial dysfunction is a predictor of postcoronary artery bypass atrial fibrillation: association of left atrial strain and strain rate assessed by speckle tracking. Echocardiography 2011;28:1104–8. CrossRef 5. Mariscalco G, Klersy C, Zanobini M, Banach M, Ferrarese S, Borsani P, et al. Atrial fibrillation after isolated coronary surgery affects late survival. Circulation 2008;118:1612–8. 6. Levy F, Debry N, Labescat AL, Meimoun P, Malaquin D, Marechaux S, et al. Echocardiographic prediction of post- operative atrial fibrillation after aortic valve replacement for aortic stenosis: a two-dimensional speckle tracking left ven- tricular longitudinal strain multicentre pilot study. Arch Car- diovasc Dis 2012;105:499–506. CrossRef 7. Melduni RM, Suri RM, Seward JB, Bailey KR, Ammash NM, Oh JK, et al. Diastolic dysfunction in patients undergoing car- diac surgery: a pathophysiological mechanism underlying the http://dx.doi.org/10.1016/j.amjcard.2011.08.033 http://dx.doi.org/10.1007/978-0-585-28007-3_3 http://dx.doi.org/10.1161/01.CIR.94.3.390 http://dx.doi.org/10.1111/j.1540-8175.2011.01518.x http://dx.doi.org/10.1161/CIRCULATIONAHA.108.777789 http://dx.doi.org/10.1016/j.acvd.2012.06.002 http://dx.doi.org/10.1016/j.jacc.2011.05.021 http://dx.doi.org/10.1111/j.1540-8167.2011.02049.x http://dx.doi.org/10.1016/j.echo.2005.10.005 http://dx.doi.org/10.1016/j.jacc.2006.02.048 http://dx.doi.org/10.4070/kcj.2012.42.5.311 http://dx.doi.org/10.1016/j.jacc.2008.02.040 http://dx.doi.org/10.1016/j.echo.2007.05.031 http://dx.doi.org/10.1016/0003-4975(93)90894-N http://dx.doi.org/10.1016/0002-9149(90)90550-K Turk Kardiyol Dern Ars52 left atrial strain and strain rate assessed by speckle tracking. Echocardiography 2011;28:1104–8. CrossRef 28. Her AY, Kim JY, Kim YH, Choi EY, Min PK, Yoon YW, et al. Left atrial strain assessed by speckle tracking imaging is related to new-onset atrial fibrillation after coronary artery bypass grafting. Can J Cardiol 2013;29:377–83. CrossRef 29. Candan O, Ozdemir N, Aung SM, Dogan C, Karabay CY, Gecmen C, et al. Left atrial longitudinal strain parameters pre- dict postoperative persistent atrial fibrillation following mitral valve surgery: a speckle tracking echocardiography study. Echocardiography 2013;30:1061–8. CrossRef 30. Haffajee JA, Lee Y, Alsheikh-Ali AA, Kuvin JT, Pandian NG, Patel AR. Pre-operative left atrial mechanical function pre- dicts risk of atrial fibrillation following cardiac surgery. JACC Cardiovasc Imaging 2011;4:833–40. CrossRef 31. Blume GG, Mcleod CJ, Barnes ME, Seward JB, Pellikka PA, Bastiansen PM, et al. Left atrial function: physiology, assessment, and clinical implications. Eur J Echocardiogr 2011;12:421–30. CrossRef 32. Notomi Y, Popovic ZB, Yamada H, Wallick DW, Martin MG, Oryszak SJ, et al. Ventricular untwisting: a temporal link be- tween left ventricular relaxation and suction. Am J Physiol Heart Circ Physiol 2008;294:505–13. CrossRef 33. Stolker JM, Rich MW. Clinical utility of B-type natriuretic peptide for estimating left ventricular filling pressures in un- selected elderly patients undergoing diagnostic coronary an- giography. J Invasive Cardiol 2010;22:107–12. 34. Cardinale D, Colombo A, Sandri MT, Lamantia G, Colombo N, Civelli M, et al. Increased perioperative N-terminal pro-B- type natriuretic peptide levels predict atrial fibrillation after thoracic surgery for lung cancer. Circulation 2007;115:1339– 44. CrossRef 35. Gibson PH, Croal BL, Cuthbertson BH, Rae D, McNeilly JD, Gibson G, et al. Use of preoperative natriuretic peptides and echocardiographic parameters in predicting new-onset atrial fibrillation after coronary artery bypass grafting: a prospective comparative study. Am Heart J 2009;158:244–51. CrossRef 19. Wazni OM, Martin DO, Marrouche NF, Latif AA, Ziada K, Shaaraoui M, et al. Plasma B-type natriuretic peptide levels predict postoperative atrial fibrillation in patients undergoing cardiac surgery. Circulation 2004;110:124–7. CrossRef 20. Lakatta EG, Levy D. Arterial and cardiac aging: major shareholders in cardiovascular disease enterprises: Part II: the aging heart in health: links to heart disease. Circulation 2003;107:346-54. CrossRef 21. Benjamin EJ, Levy D, Anderson KM, Wolf PA, Plehn JF, Ev- ans JC, et al. Determinants of Doppler indexes of left ven- tricular diastolic function in normal subjects (the Framingham Heart Study). Am J Cardiol 1992;70:508–15. CrossRef 22. Mondillo S, Galderisi M, Mele D, Cameli M, Lomoriello VS, Zacà V, et al. Speckle-tracking echocardiography: a new tech- nique for assessing myocardial function. J Ultrasound Med 2011;30:71–83. 23. Mor-Avi V, Lang RM, Badano LP, Belohlavek M, Cardim NM, Derumeaux G, et al. Current and evolving echocardio- graphic techniques for the quantitative evaluation of cardiac mechanics: ASE/EAE consensus statement on methodology and indications endorsed by the Japanese Society of Echocar- diography. J Am Soc Echocardiogr 2011;24:277–313. CrossRef 24. Kojima T, Kawasaki M, Tanaka R, Ono K, Hirose T, Iwama M, et al. Left atrial global and regional function in patients with paroxysmal atrial fibrillation has already been impaired before enlargement of left atrium: velocity vector imaging echocardiography study. Eur Heart J Cardiovasc Imaging 2012;13:227–34. CrossRef 25. Hammerstingl C, Schwekendiek M, Momcilovic D, Schueler R, Sinning JM, Schrickel JW, et al. Left atrial deformation imaging with ultrasound based two-dimensional speckle- tracking predicts the rate of recurrence of paroxysmal and per- sistent atrial fibrillation after successful ablation procedures. J Cardiovasc Electrophysiol 2012;23:247–55. CrossRef 26. Tayyareci Y, Yildirimtürk O, Aytekin V, Memic K, Behramo- glu F, Demiroglu IC, et al. Preoperative left atrial mechani- cal dysfunction predicts postoperative atrial fibrillation after coronary artery bypass graft operation – a velocity vector imaging-based study –.Circ J 2010;74:2109–17. CrossRef 27. Gabrielli L, Corbalan R, Córdova S, Enríquez A, Mc Nab P, Verdejo HE, et al. Left atrial dysfunction is a predictor of postcoronary artery bypass atrial fibrillation: association of Keywords: Atrial fibrillation; coronary artery disease; left atrial strain; left ventricular strain; speckle tracking echocardiography. Anahtar sözcükler: Atriyum fibrilasyonu; koroner arter hastalığı; sol atriyal strain; sol ventriküler strain; speckle tracking ekokardiyografi. http://dx.doi.org/10.1161/01.CIR.0000134481.24511.BC http://dx.doi.org/10.1161/01.CIR.0000048893.62841.F7 http://dx.doi.org/10.1016/0002-9149(92)91199-E http://dx.doi.org/10.1016/j.echo.2011.01.015 http://dx.doi.org/10.1093/ejechocard/jer281 http://dx.doi.org/10.1111/j.1540-8167.2011.02177.x http://dx.doi.org/10.1253/circj.CJ-10-0197 http://dx.doi.org/10.1111/j.1540-8175.2011.01518.x http://dx.doi.org/10.1016/j.cjca.2012.06.006 http://dx.doi.org/10.1111/echo.12222 http://dx.doi.org/10.1016/j.jcmg.2011.03.019 http://dx.doi.org/10.1093/ejechocard/jeq175 http://dx.doi.org/10.1152/ajpheart.00975.2007 http://dx.doi.org/10.1161/CIRCULATIONAHA.106.647008 http://dx.doi.org/10.1016/j.ahj.2009.04.026