DOI: 10.1111/j.1540-8175.2009.00996.x C  2010, Wiley Periodicals, Inc. Left Ventricular Untwisting in Restrictive and Pseudorestrictive Left Ventricular Filling: Novel Insights into Diastology Bas M. van Dalen, M.D., Osama I. I. Soliman, M.D., Ph.D., Wim B. Vletter, M.Sc., Folkert J. ten Cate, M.D., Ph.D., and Marcel L. Geleijnse, M.D., Ph.D. Department of Cardiology, The Thoraxcenter, Erasmus University Medical Center, Rotterdam, The Netherlands Background: Conceptually, an ideal therapeutic agent should target the underlying mechanisms that cause left ventricular (LV) diastolic dysfunction. The objective of our study was to gain further insight into the mechanics of diastology by comparison of LV untwisting measured by speckle tracking echocar- diography (STE) in young healthy adults with normal and “pseudorestrictive” LV filling, and dilated cardiomyopathy (DCM) patients with “true restrictive” LV filling. Methods: The study comprised 20 healthy volunteers with a Doppler LV-inflow pattern compatible with restrictive LV filling but a diastolic early phase filling velocity/early diastolic velocity of the mitral annulus (E/Em) ratio <8 (“pseudorestric- tive”), 20 for age and gender-matched healthy volunteers with normal LV filling and an E/Em ratio <8, and 10 DCM patients with “true restrictive” LV filling and an E/Em ratio >15. LV untwisting parameters were determined by STE. Results: Compared to healthy subjects, DCM patients had decreased peak diastolic untwisting velocity (−62 ± 33 degrees/s vs −113 ± 25 degrees/s, P < 0.01) and untwisting rate (−15 ± 9 degrees/s vs −51 ± 24 degrees/s, P < 0.01). Compared to healthy subjects with normal LV filling, healthy subjects with “pseudorestrictive” LV filling had increased peak diastolic untwisting velocity (−123 ± 25 degrees/s vs −104 ± 30 degrees/s, P < 0.05) and untwisting rate (−59 ± 23 degrees/s vs −44 ± 22 degrees/s, P < 0.05). Conclusion: Faster LV untwisting plays a pivotal role in the rapid early diastolic filling occasionally seen in young healthy individuals. In contrast, in DCM patients untwisting is severely delayed and this impairment to utilize suction may reduce LV filling. (Echocardiography 2010;27:269-274) Key words: echocardiography, diastolic function, diastolic dysfunction, dilated cardiomyopathy It has become widely recognized that virtually all forms of acquired organic heart disease are associated with a component of left ventricular (LV) diastolic dysfunction. 1 Doppler echocardio- graphy is the most often used technique to study LV diastolic function. 2,3 At the end of the spec- trum of diastolic dysfunction is a restrictive LV filling pattern. However, in healthy adolescents and young adults, there may be a marked contri- bution of active LV relaxation to LV filling, result- ing in an accentuated diastolic early phase filling velocity (E) with a short deceleration time, that resembles a restrictive LV filling pattern (“pseu- dorestrictive”). 4,5 Echocardiographic differentia- tion of this physiological phenomenon from a true pathological restrictive LV filling pattern can be done by evaluation of left atrial size, pulmonary vein velocity, and the early diastolic velocity Address for correspondence and reprint requests: Marcel L. Geleijnse, M.D., Ph.D., Erasmus University Medical Center, Thoraxcenter, Room BA 302, ’s-Gravendijkwal 230, 3015 CE Rotterdam, The Netherlands. Fax: +31-10-4635498; E-mail: m.geleijnse@erasmusmc.nl of the mitral annulus (Em). 6 Before mitral valve opening, in the isovolumic relaxation period, un- twist of the obliquely oriented fibers of the LV con- tributes to the generation of the intraventricular pressure gradient, which leads to LV diastolic suc- tion, a major determinant of early LV filling. 7,8 LV untwisting assessed by speckle tracking echocar- diography (STE) may provide a novel index to assess LV diastolic function. 9 The objective of our study was to gain further insight into the mechan- ics of diastology by comparison of LV untwisting measured by STE in young healthy adults with a normal and a “pseudorestrictive” LV filling pat- tern, and dilated cardiomyopathy (DCM) patients with a “true restrictive” LV filling pattern. Methods: Study Participants: The study population consisted of 20 consecutive healthy volunteers (mean age 29 ± 8 year, 13 males) with a Doppler LV-inflow pattern compat- ible with restrictive LV filling but an E/Em ratio <8 (“pseudorestrictive”), 20 for age and gender- matched healthy volunteers with a normal LV 269