Left Ventricular Twist Mechanics in Hypertrophic Cardiomyopathy Assessed by Three-Dimensional Speckle Tracking Echocardiography Jose A. Urbano Moral, MD*, Jose A. Arias Godinez, MD, Martin S. Maron, MD, Rabiya Malik, MD, Jacqueline E. Eagan, BS, Ayan R. Patel, MD, and Natesa G. Pandian, MD Left ventricular (LV) twist represents a phenomenon that links systolic contraction with diastolic relaxation and plays a major role in cardiac physiology; thus, the study of twist mechanics is of particular interest in hypertrophic cardiomyopathy (HC). Three-dimen- sional speckle tracking echocardiography (3D-STE) has the potential to overcome the limitations of 2-dimensional imaging and provide a greater understanding of LV twist in HC. We aimed to examine LV twist mechanics in HC using 3D-STE. Echocardiograms from subjects with a diagnosis of HC were examined for 3D-STE analysis. Age- and gender-matched healthy subjects were tested as a control group. Forty patients with HC (age 37  16 years; 42.5% women) and 40 control subjects (age 35  10 years; 42.5% women) were examined. Compared with the controls, the patients with HC showed increased peak LV twist (16.5  4.7° vs 12.0  3.9°, p <0.001) mainly because of increased apical rotation of those with LV outflow tract obstruction (obstruction, 12.7  4.4° vs nonobstruction, 9.7  2.8°, p  0.02). In addition, the patients with HC displayed onset of torsion recoil occurring closer to the aortic valve closure (94  6% vs 85  6%, p <0.001; time normalized by the length of systole), limited completion of untwist during early diastole (31  12% vs 62  15%, p <0.001), and delayed peak untwist velocity (22  7% vs 13  9%, p <0.001; time normalized by the length of diastole). In conclusion, the evaluation of twist mechanics using 3D-STE provides novel insight regarding alterations in LV mechanics in patients with HC. Elucidating the characteristics of the wringing motion of the heart might help to broaden the understanding of the hyperdynamic contraction and impaired relaxation observed in these patients. © 2011 Elsevier Inc. All rights reserved. (Am J Cardiol 2011;108:1788 –1795) Left ventricular (LV) twist represents a phenomenon that links systolic contraction with diastolic relaxation and plays a major role in cardiac physiology. 1–4 Speckle tracking echocardiography (STE), based on tracking and measure- ment of tissue displacement, has the potential for accurate and reliable assessment of myocardial mechanics, 5 provid- ing a relatively simple, noninvasive approach to the study of LV rotation and twist. 6 The presence, in patients with hy- pertrophic cardiomyopathy (HC), of a supranormal ejection fraction within a clearly diseased myocardium, and impor- tant limitations of transmitral velocities and tissue Doppler imaging for the estimation of filling abnormalities 7 has generated interest in evaluating the usefulness of STE for HC, 8 –10 where its application might help to widen the un- derstanding of the complex pathophysiology of HC. Despite interest in STE for the assessment of HC through rotational and twist parameters, the available data are quite scarce and limited to a few reports, 8 –11 all of which used 2-dimensional technology, with the inherent limitation of tracking out-of- plane tissue motion. 12 The aim of the present study was to describe LV twist mechanics in HC using 3-dimensional (3D)-STE. Methods We examined outpatients referred to our echocardiogra- phy laboratory from the Hypertrophic Cardiomyopathy Center (Tufts Medical Center, Boston, Massachusetts). In- clusion required a diagnosis of HC (the demonstration of a hypertrophied nondilated left ventricle [in adults, a wall thickness of 15 mm; in children, a wall thickness +2 SDs of normal values according to body surface area 13] ) and the absence of hypertension, diabetes mellitus, or any other cardiac or systemic disease that could produce the magni- tude of hypertrophy evident. In addition, sinus rhythm had to be present at echocardiography. Left ventricular outflow tract obstruction was considered when an at rest or provo- cable (Valsalva maneuver) gradient of 30 mm Hg was detected. The patients were questioned in detail about their history and symptoms of coronary artery disease and were excluded if they provided any history suggesting this condition From the Cardiovascular Imaging and Hemodynamic Laboratory, Tufts Medical Center, Boston Massachusetts. Manuscript received May 30, 2011; manuscript received and accepted July 20, 2011. The Cardiovascular Imaging and Hemodynamic Laboratory at Tufts Medical Center (Boston, Massachusetts) received an equipment grant from Toshiba Medical Systems (Tustin, California). *Corresponding author: Tel: 617-636-6151; fax: 617-636-8070. E-mail address: jurbanomoral@tuftsmedicalcenter.org (J. A. Urbano Moral). 0002-9149/11/$ – see front matter © 2011 Elsevier Inc. All rights reserved. www.ajconline.org doi:10.1016/j.amjcard.2011.07.047