Four-Dimensional Speckle Tracking Echocardiography in Patients with Hypertrophic Cardiomyopathy Kadriye Orta Kilickesmez, M.D., Onur Baydar, M.D., Cem Bostan, M.D., Ugur Coskun, M.D., and Serdar Kucukoglu, M.D. Department of Cardiology, Istanbul University Institute of Cardiology, Istanbul, Turkey Objective: Abnormal left ventricular (LV) deformational mechanics have been demonstrated in patients with hypertrophic cardiomyopathy (HCM) using two-dimensional (2D) speckle tracking echocardiogra- phy, but there is not enough information about the four-dimensional speckle tracking echocardiogra- phy (4DSTE) in these patients. The objective of the study was to identify and quantify the left ventricular contractility in patients with HCM using 4DSTE. Methods: Thirty patients [age, 54.6 Æ 12.1 years; 12 (40%) women] with diagnosis of nonobstructive HCM and 20 healthy controls [age, 47.42 Æ 11.43 years; 8 (40%) women] underwent 4DSTE measurement of longitudinal, radial, circumferential, and area strains. Results: Patients with HCM showed lower longitudinal (À13.5% vs. À20.3%, P < 0.001) and radial (33.4% vs. 43.6%, P < 0.001) strain, but higher circumferential (À22.7% vs. À15.9%, P < 0.001) and area (À30.7% vs. À22.1%, P < 0.001) strain than control sub- jects. Peak LV twist showed significantly higher values in patients with HCM (13.7 Æ 5.3 vs. 11.3 Æ 4.8, P < 0.005). Conclusions: Patients with HCM have reduced longitudinal and radial strain but increased circumferential and area strain on 4DSTE. These results are found appropriate with previ- ous 2DSTE studies. Thus, 4DSTE is useful to determine LV deformational mechanics. (Echocardiography 2015;32:1547–1553) Key words: hypertrophic cardiomyopathy, speckle tracking, four-dimensional, echocardiography Hypertrophic cardiomyopathy (HCM) is described as a hypertrophied and nondilated left ventricle (LV), often with an asymmetrical distri- bution of wall thickness. 1,2 Myocardial tissue alterations in HCM are mainly affected by myofi- ber disarray and focal scarring, dominating the septal and anteroseptal regions of the heart, which results in overall impaired mechanical function. 3 Left ventricular wall contraction can be esti- mated by four-chamber echographic analysis of the heart in B-mode, however, that evaluation remains subjective and operator dependent. Speckle tracking echocardiography (STE) was based on tracking and measurement of tissue dis- placement, satisfactory for accurate assessment of myocardial mechanics 4 and providing a relatively simple, noninvasive approach to the detection of LV rotation and twist. 5 The four- dimensional (4D) speckle tracking method acquires a 3D view of the heart and allows for the real-time visualization of change in strain in every segment of the left ventricle using color map- ping. 6,7 Studies based on magnetic resonance imaging (MRI) 8 or STE 3,9–11 in HCM have docu- mented altered LV strains and twist–untwist mechanics. All studies reported reduced longitu- dinal strain but yielded discordant data regarding radial 8,12 and circumferential 12,13 strains. More- over, there is not enough information about the four-dimensional (4D) speckle tracking echocar- diography (4DSTE) in these patients. The aim of this study was to evaluate the change in 4D strain, which summarizes all the strain changes in three directions and area, and also global twist in patients with HCM and com- paring them to healthy controls. Methods: We examined 30 consecutive patients with a diagnosis of HCM referred to our echocardiogra- phy laboratory from the outpatient clinic between January 2012 and March 2013. Inclu- sion required an echocardiography showing a maximal septal thickness of at least 15 mm in all patients, in the absence of hypertension, or any other cardiac or systemic disease that could cause LV hypertrophy. All patients were in sinus rhythm and had LV ejection fraction >50%. Patients were Address for correspondence and reprint requests: Kadriye Orta Kilickesmez, M.D., Department of Cardiology, Istanbul University Institute of Cardiology, Haseki, Aksaray 34350, Istanbul, Turkey. Fax: +90 216 469 3796; E-mail: kadriye11@yahoo.com 1547 © 2015, Wiley Periodicals, Inc. DOI: 10.1111/echo.12916 Echocardiography