Strain by Nuclear Magnetic Resonance in Hypertrophic Cardiomyopathy

pp 342-346

Abstract

Background: New techniques have been developed for the quantitative analysis of myocardial deformation by cardiovascular magnetic resonance from cine-sequences (as feature tracking) or from sequences with myocardial saturation bands (tagging), enabling a reliable 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 deformation by 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 April 2016. Wall thickness values were estimated and endocardial and epicardial borders were traced for calculation of ventricular volumes and mass. Four-chamber and short-axis cine and tagging sequences defined the borders to analyze deformation or myocardial strain by feature tracking and myocardial tagging; values of global longitudinal, circumferential and radial strain were obtained and segmental strain curves were established.
Results: Mean ejection fraction in the overall population was 72%±9%. In the analysis of myocardial deformation by feature-tracking from 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 strains were -7%±3% and -17%±3%, respectively.
Conclusions: A global preserved ejection fraction was estimated in this population with hypertrophic cardiomyopathy, despite having a significant decrease in longitudinal, circumferential and radial myocardial deformation. That is why the new analysis techniques by cardiac MRI allow a deeper understanding of the real systolic function of patients suffering from this disease.