Global and regional myocardial function quantification by two-dimensional strain - Application in hypertrophic cardiomyopathy

OBJECTIVES Recently, a novel method to measure strain from standard two-dimensional images has been developed. Our goal was to characterize global and regional systolic function abnormalities using this technique in patients with hypertrophic cardiomyopathy (HCM). BACKGROUND Strain has been proposed as a sensitive tool to detect early systolic function abnormalities in HCM. However, the clinical application of conventional Doppler-derived strain has been limited by poor reproducibility and angle dependency. METHODS Echocardiographic examinations were performed in 26 patients with nonobstructive HCM and 45 healthy subjects. Using a dedicated software package, bidimensional acquisitions were analyzed to measure longitudinal and transverse strain in apical views and circumferential and radial strain in parasternal short-axis view. RESULTS Despite apparently normal left ventricular systolic function, all components of strain were significantly reduced in HCM. Average longitudinal, transverse, circumferential, and radial strain in patients with HCM and controls were -15.1 +/- 6.2% versus -20.3 +/- 5.6%, 23.3 +/- 17.0% versus 27.2 +/- 14.9%, -16.8 +/- 7.1% versus 19.6 +/- 5.2%, and 25.2 +/- 13.9% versus 36.8 +/- 17.2%, respectively (all p < 0.001). In patients with asymmetrical HCM, longitudinal septal strain was significantly lower than for other left ventricular segments combined: - 9.2 +/- 4.7% versus -12.7 +/- 7.1% (p = 0.001). Average interobserver and intraobserver variabilities were 11% and 11.3%, respectively. CONCLUSIONS Two-dimensional strain is a new simple, rapid, and reproducible method to measure different components of systolic strain. This technique identified early abnormalities in patients with HCM that have apparently normal left ventricular systolic function.