Strain by Nuclear Magnetic Resonance in Hypertrophic Cardiomyopathy

Background: New techniques have been developed for the quantitative analysis of myocardial deformation by cardiovascular magneticresonance from cine-sequences (as feature tracking) or from sequences with myocardial saturation bands (tagging), enabling areliable evaluation of the true systolic function in patients with hypertrophic cardiomyopathy.Objectives: The aim of this study was to assess systolic function expressed as evaluation of ejection fraction and myocardial deformationby new analysis techniques in a population with hypertrophic cardiomyopathy.Methods: Forty patients with hypertrophic cardiomyopathy were retrospectively included in the study between April 2009 and April2016. Wall thickness values were estimated and endocardial and epicardial borders were traced for calculation of ventricular volumesand mass. Four-chamber and short-axis cine and tagging sequences defined the borders to analyze deformation or myocardialstrain by feature tracking and myocardial tagging; values of global longitudinal, circumferential and radial strain were obtained andsegmental strain curves were established.Results: Mean ejection fraction in the overall population was 72%±9%. In the analysis of myocardial deformation by feature-trackingfrom 4-chamber and short-axis cine sequences, mean global longitudinal strain was -9.9%±3%, circumferential strain -14%±5%and radial strain 33%±10%. In the values obtained by myocardial tagging, mean global longitudinal and circumferential strainswere -7%±3% and -17%±3%, respectively.Conclusions: A global preserved ejection fraction was estimated in this population with hypertrophic cardiomyopathy, despite havinga significant decrease in longitudinal, circumferential and radial myocardial deformation. That is why the new analysis techniquesby cardiac MRI allow a deeper understanding of the real systolic function of patients suffering from this disease.