Echocardiographic reference ranges for normal left ventricular layer-specific strain: results from the EACVI NORRE study
Toshimitsu Tsugu, Adriana Postolache, Raluca Dulgheru, Tadafumi Sugimoto, Julien Tridetti, Mai‐Linh Nguyen Trung, Caroline Piette, Marie Moonen, Roberta Manganaro, Federica Ilardi, Alexandra Maria Chitroceanu, Simona Sperlongano, Yun Yun Go, George Kacharava, George Athanassopoulos, Daniele Barone, Monica Baroni, Nuno Cardim, Andreas Hagendorff, Krasimira Hristová, Teresa López‐Fernández, Gonzalo de la Morena, Bogdan A. Popescu, Martin Pěnička, Tolga Özyiğit, D. Rodrigo Carbonero, Nico Van de Veire, Ralph Stephan von Bardeleben, Dragoş Vinereanu, José Luis Zamorano, Monica Roşca, Andreea Călin, Julien Magné, Bernard Cosyns, Elena Galli, Erwan Donal, Ciro Santoro, Maurizio Galderisi, Luigi P. Badano, Roberto M. Lang, Patrizio Lancellotti
Abstract
AIMS: To obtain the normal range for 2D echocardiographic (2DE) measurements of left ventricular (LV) layer-specific strain from a large group of healthy volunteers of both genders over a wide range of ages. METHODS AND RESULTS: A total of 287 (109 men, mean age: 46 ± 14 years) healthy subjects were enrolled at 22 collaborating institutions of the EACVI Normal Reference Ranges for Echocardiography (NORRE) study. Layer-specific strain was analysed from the apical two-, three-, and four-chamber views using 2DE software. The lowest values of layer-specific strain calculated as ±1.96 standard deviations from the mean were -15.0% in men and -15.6% in women for epicardial strain, -16.8% and -17.7% for mid-myocardial strain, and -18.7% and -19.9% for endocardial strain, respectively. Basal-epicardial and mid-myocardial strain decreased with age in women (epicardial; P = 0.008, mid-myocardial; P = 0.003) and correlated with age (epicardial; r = -0.20, P = 0.007, mid-myocardial; r = -0.21, P = 0.006, endocardial; r = -0.23, P = 0.002), whereas apical-epicardial, mid-myocardial strain increased with the age in women (epicardial; P = 0.006, mid-myocardial; P = 0.03) and correlated with age (epicardial; r = 0.16, P = 0.04). End/Epi ratio at the apex was higher than at the middle and basal levels of LV in men (apex; 1.6 ± 0.2, middle; 1.2 ± 0.1, base 1.1 ± 0.1) and women (apex; 1.6 ± 0.1, middle; 1.1 ± 0.1, base 1.2 ± 0.1). CONCLUSION: The NORRE study provides useful 2DE reference ranges for novel indices of layer-specific strain.