Global and regional myocardial function quantification by two-dimensional strain: application in hypertrophic cardiomyopathy.

Abstract

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.