ABSTRACT
Recordings of aortic root movement represent one of the first accomplishments of ultrasound in medicine and mark the beginning of functional cardiac imaging. However, the underlying mechanism is not completely understood. Since the aortic root is directly connected to the cardiac skeleton we hypothesize, that the amplitude of systolic aortic root motion (SARM) may be mainly caused by displacement of the cardiac base towards the apex and might therefore be used as measure of left ventricular longitudinal function (LV-LF). One hundred and eighty patients with dilated cardiomyopathy and 180 healthy controls were prospectively included into this study. SARM was lower in patients compared to controls (9 ± 3 mm vs. 12 ± 2 mm, p < 0.001) and lowest in patients with cardiovascular events (9 ± 3 mm vs. 7 ± 3 mm, p < 0.001). During a median follow-up time of 38 months, the combined end-point of cardiovascular death or hospitalization for heart failure was reached by 25 patients (13.9%). Reduced SARM had significant prognostic impact on outcome (hazard ratio 0.74, 95% confidence interval 0.63-0.88, p < 0.001) and remained an independent predictor in the multivariate analysis. Compared to parameters with potential influence on its mechanism, SARM correlated best (r = 0.75, p < 0.001) with global longitudinal strain (GLS). SARM may therefore represent an alternative echocardiographic parameter for the assessment of LV-LF, particularly when GLS is not feasible or apical views are not available.
Subject(s)
Aorta/diagnostic imaging , Cardiomyopathy, Dilated/diagnostic imaging , Echocardiography , Aged , Aorta/physiopathology , Cardiomyopathy, Dilated/physiopathology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Motion , Prognosis , Prospective Studies , Systole , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/physiopathology , Ventricular Function, LeftABSTRACT
BACKGROUND: Impaired left ventricular (LV) longitudinal function (LF) is a known predictor of cardiac events in patients with heart failure, but two-dimensional strain imaging, the reference method to measure myocardial deformation, is not always feasible or available. Therefore, reliable and reproducible alternatives are needed. The aim of the present study was to evaluate unidimensional longitudinal strain (ULS) as a simple echocardiographic parameter for the assessment of LV LF. METHODS: Two hundred two patients with dilated cardiomyopathy who had their first presentation in the authors' cardiology department, as well as the same number of age- and gender-matched control subjects, were prospectively included in this study. ULS was compared with global longitudinal strain (GLS), the current gold standard for LV LF assessment by echocardiography. Uni- and multivariate Cox regression analyses were conducted to evaluate the prognostic value of ULS. RESULTS: LV LF was higher in the control group compared with patients: GLS -19.5 ± 1.7% versus -12.6 ± 4.8% and ULS -16.3 ± 1.5% versus -10.2 ± 3.9% (P < .001 for each). Correlation between ULS and GLS was excellent (r = 0.94), while Bland-Altman plots revealed lower values for ULS (bias -2.76%, limits of agreement ±3.31%). During a mean follow-up time of 39 months, the combined end point of cardiovascular death or hospitalization for acute cardiac decompensation was reached by 28 patients (13.9%). GLS (hazard ratio, 1.21; 95% CI, 1.10-1.34; P < .001) and ULS (hazard ratio, 1.24; 95% CI, 1.12-1.39; P < .001) had comparable prognostic impact on patient outcomes. CONCLUSIONS: ULS might be an alternative echocardiographic method for the assessment of LV LF, with similar diagnostic and prognostic value compared with GLS.
