Left Ventricular Strain Analysis During Submaximal Semisupine Bicycle Exercise Stress Echocardiography in Childhood Cancer Survivors.

Background Childhood cancer survivors (CCSs) show relevant cardiac morbidity and mortality throughout life. Early detection is key for optimal support of patients at risk. The aim of this study was to evaluate 2-dimensional speckle-tracking echocardiography strain analysis during semisupine exercise stress in CCSs for detection of subclinical left ventricular dysfunction after cancer treatment. Methods and Results Seventy-seven CCSs ≥1-year postchemotherapy were prospectively examined at rest, low, and submaximal stress level and compared with a cohort of healthy adolescents and young adults (n=50). Global longitudinal strain (GLS), short axis circumferential strain, and corresponding strain rates were analyzed using vendor-independent software. CCSs at median 7.8 years postchemotherapy showed comparable left ventricular GLS, circumferential strain, and strain rate values at all stress stages to healthy controls. Yet, prevalence of abnormal GLS (defined as <2 SD of controls reference) in CCSs was 1.3% at rest, 2.7% at low, and 8.6% at submaximal stress. In CCSs, relative change of circumferential strain from rest to submaximal stress was lower than in healthy controls, median 16.9 (interquartile range [IQR], 3.4; 28.8) % versus 23.3 (IQR, 11.3; 33.3) %, P=0.03, most apparent in the subgroups of CCSs after high-dose anthracycline treatment and cancer diagnosis before the age of 5 years. Conclusions In this prospective 2-dimensional speckle tracking echocardiography strain study, prevalence of abnormal left ventricular GLS increased with stress level reflecting impaired cardiac adaptation to exercise stress in some CCSs. However, relatively early after last chemotherapy, this did not result in significant differences of mean GLS-, circumferential strain-, and strain rate values between CCSs and controls at any stress level.

Left Ventricular Strain and Strain Rate during Submaximal Semisupine Bicycle Exercise Stress Echocardiography in Healthy Adolescents and Young Adults: Systematic Protocol and Reference Values.

OBJECTIVE: Combining stress echocardiography with strain analysis is a promising approach for early detection of subclinical cardiac dysfunction not apparent at rest. Data on normal myocardial strain and strain rate (SR) response to exercise in adolescents and young adults are contradictory and limited. The aim of this study was to propose a standardized protocol for semisupine bicycle stress echocardiography and to provide corresponding reference values of left ventricular (LV) two-dimensional speckle-tracking echocardiography (2D STE) strain and SR in adolescents and young adults. METHODS: Fifty healthy adolescents and young adults (mean age, 17.8 ± 3.2 years, 44% female) were prospectively assessed. Images were acquired at rest, low stress, submaximal stress, and during recovery. Optimal image quality for offline strain analysis was pursued, and image quality was rated. Global longitudinal strain and SR from apical four-/two-/three-chamber views and short-axis circumferential strain and SR were analyzed using vendor-independent software. Interobserver variability was assessed. RESULTS: Strain and SR increased during progressive exercise stress. Mean LV global longitudinal strain was -20.4% ± 1.3%, SR -1.1 ± 0.15/sec at rest (heart rate, 79.4 ± 12.0 beats/minute), increasing to -22.6% ± 1.6% and -1.5 ± 0.16/sec at low stress level (heart rate, 117.1 ± 8.7 beats/minute) and -23.7% ± 1.1% and -1.9 ± 0.29/sec at submaximal stress level (heart rate, 154.2 ± 7.0 beats/minute), respectively, returning to -20.6% ± 1.4% and -1.2 ± 0.16/sec postexercise (heart rate, 90.1 ± 9.4 beats/minute). Restriction on submaximal stress level ensured adequate image quality for 2D STE strain analysis. Interobserver variability for strain was acceptable even during submaximal stress. CONCLUSIONS: This study provides a systematic, standardized protocol and corresponding reference data for 2D LV STE-derived strain and SR during semisupine bicycle exercise testing in adolescents and young adults. According to our results, global longitudinal strain and SR appear to be the most comprehensible parameters for cross-sectional studies.