Background: Evaluation of tissue fibrosis and myocardial hypertrophy in left ventricular (LV) remodeling is the basis of post-treatment evaluation of hypertensive heart disease (HHD). Extracellular volume (ECV) and myocardial strain parameters can indirectly reflect the changes of both. Our objective was to analyze the characteristics of ECV and strain parameters in LV myocardium of HHD with varying degrees of systolic dysfunction, and to explore the changes of both after treatment for hypertension. Methods: A total of 62 HHD patients were divided into 3 groups according to ejection fraction (EF < 30, 30%≦EF < 50%, EF≧50%). Twenty-one of these patients underwent cardiac magnetic resonance (CMR) reexamination more than six months after receiving antihypertensive medication. The initial T1 time and post-enhancement T1 time of each segment were measured, and the ECV was calculated. Radial strain (RS), circumferential strain (CS) and longitudinal strain (LS) of LV were measured by cvi42 software, and the differences in CMR parameters between different groups and before and after treatment were compared. Results: ①The mean, basal and middle ECV value of HHD groups with different EF were all higher than that of the control group (P < 0.05), but the difference between HHD groups was not statistically significant. ②With the decrease of EF, the absolute value of both the global or local strain decreased. Strain is related to LVMI and ECV. ③In general, ECV, global RS (GRS) and global CS (GCS) improved after treatment, but the improvement of LS impairment in HHD patients is difficult. Conclusions: ECV and myocardial strain parameters are more sensitive to myocardial abnormalities, and ECV, GRS and GCS are more sensitive to treatment. However it is difficult to improve longitudinal strain impairment in HHD patients. ECV and myocardial strain parameters can be used as good makers for long-term monitoring of the efficacy of HHD patients.
The black-throated tit, Aegithalos concinnus, and long-tailed tit, A. caudatus, are two widely-distributed species of Aegithalidae. They are thought to be monomorphic and thus difficult to differentiate between sexes in the field. We determined the sex of 296 black-throated tits and 129 long-tailed tits using DNA analysis, evaluated their sexual size dimorphism, and developed discriminant models to identify sex based on morphometries, including bill length, bill depth, bill-head length, maximum tarsus length, tarsus width, wing length, tail length, total body length, and body mass. Both species were sexually dimorphic in size, with males having larger measurements than females, except for bill length in black-throated tits, and both bill length and body mass in long-tailed tits. Moreover, both species showed similar sexual size dimorphism (SSD) among the morphological features, with tail length having the highest SSD value. The multivariate discriminant models for sex identification had an accuracy of 82% for both species, which was slightly higher than the best univariate discriminatory model for each species. Because of the complicated nature of the multivariate model, we recommend univariate models for sex identification using D = 0.491 × tail length - 24.498 (accuracy 80%) for black-throated tits and D = 0.807 × wing length - 45.934 (accuracy 78%) for long-tailed tits. Females in both species showed generally higher morphological variation than did males, resulting in lower accuracies in all discriminate functions regardless of univariate or multivariate approach. This could be the result of a sex-biased selective pressure in which males have higher selective pressures for these morphological features.
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