Systolic Aortic Root Motion and Angle as novel indices of Left Ventricular Systolic Function

Aortic root motion was used only as a surrogate parameter of global left ventricular systolic function depending on its direct proportion to cardiac output. We hypothesize that aortic root motion angle and aortic root motion amplitude may overcome many limitations of EF calculation by M mode and two dimensional methods and are easier and reproducible. The aim of this study is to asses systolic aortic root motion measured by M mode and aortic root motion angle as novel indices of global left ventricular systolic function. best cutoff aortic root 8.5 An aortic root SAM of ˂ 8.5 mm predicts an LVEF of ˂ 50% with sensitivity of 95.9%, specificity of 96.1%.


Introduction
Assessment of left ventricular (LV) systolic function is important for diagnosis, management, follow-up, and prognostic evaluation of patients in a variety of clinical settings. Accurate and reproducible determination of LV systolic function is of paramount importance in clinical practice. (1)(2) There are currently several echocardiographic measures of LV function available, as methodology has moved from linear measurements, via two-dimensional (2D) echocardiography with volume estimation and regional and global deformation analysis, to three-dimensional (3D) echocardiography (3)(4). Assessment of LV function is challenging even with better and more automated methods. Ideally, one wants a sensitive and accurate measurement of LV function that correlates with the patient's symptoms, provides important information about the course of illness and can guide therapy. There is, however, no such perfect parameter (5)(6).
The different components of myocardial fiber architecture contributing to a normal systolic function are unequally affected by different cardiac diseases, making different echocardiographic measures of LV systolic function more or less sensitive to detect subtle myocardial dysfunction. All the left ventricle function parameters measure contraction or volumes, and are therefore affected by loading conditions, which must be taken into account in every interpretation of LV function. (7)(8).
The aortic root is the anatomical bridge between the left ventricle and the ascending aorta .The anterior and posterior walls of the aortic root are recognized as a pair of parall linear signals which move anteriorly in systole and posteriorly in diastole. (9)(10) .It is subjected to the same shearing force as left ventricle so we hypothesize that angle of its motion and also the amplitude of its motion are in direct proportion to systolic function of the left ventricle .

Patients and Methods
This prospective case-control study included (100)

Statistical analysis
Data were collected and coded then entered into a spread sheet using Microsoft Excel for windows office 2010. Data were statistically analyzed using the Statistical Package of Social Science (SPSS). Quantitative data expressed as the mean ±standard deviation (SD) or standard error (SE). SE=SD/square root of patients' number which was used in case of big SD, data were analyzed by independent sample, paired t-test and one-way analysis of variance (ANOVA) followed by Tukey test whenever single-step multiple comparisons were needed to maintain the integrity of data. While, qualitative data were expressed as number and percentage and were analyzed by Chi-square (X 2 ) test. The correlation was done using a Pearson correlation test. The receiver operating characteristic (ROC) curve and 95% confidence interval (CI) was performed to determine cutoff values for the studied measures. Sensitivity and specificity were determined. P-value was considered significant if < 0.05 and highly significant if < 0.001.

Participants
The study was conducted on one hundred subjects (51%) of them were males and (49%) of them were females with mean age of 68. 6   Regarding aortic root motion angle and amplitude Significant differences between groups 1& 2 and groups 3&4 in aortic root motion angle with t = 16.945 and p value < 0.001, Significant differences between groups 1& 2 and groups 3&4 in aortic root motion amplitude with t = 20.1 and p value < 0.001 .
Also there are Significant differences between groups 1& 2 and patient groups 3&4 in global longitudinal Strain with t= -13.19 and p value < 0.001  respectively.

Discussion
In this study we tried to use systolic aortic root motion (M mode)and aortic root motion In our study we founded that SARM was lower in patients compared to controls (5.    ROC curve for the best sensitivity and specificity of aortic root motion angle.