The following experiments were designed to determine if territorial stress, dietary sodium (Na), or the combination of stress and Na effect the rate of development of hypertension in the spontaneously hypertensive rat (SHR 4-18 wks) and if central catecholamines (C) were altered by these treatments. BP was significantly elevated from 2-8 weeks of stress treatment as compared to SHR controls. Norepinephrine (NE) levels in the nucleus tractus solitarius and amygdala (A), and dopamine (D) levels in the hippocampus and A showed significant elevations in the stressed group. High Na (3%) treatment combined with stress treatment produced an even further BP increase and elevated D levels in the amygdala, and elevated NE levels in the area postrema as compared to control SHR's. Selected brain C variables were able to correctly classify animals into high and low BP groups with 90-100% accuracy. Our data support the concept that there are important stress and Na effects upon brain neurochemistry which influence the development of hypertension in the SHR.
Cardiac magnetic resonance (CMR) assesses myocardial involvement in myocarditis (MYO). Current techniques are qualitative, subjective, and prone to interpretation error. Feature tracking (FT) analyzes myocardial strain using CMR and has not been examined in MYO. We hypothesize that regional left ventricular (LV) strain is abnormal in MYO. Regional strain by FT was compared to late gadolinium enhancement (LGE) and troponin leak as measures of myocardial involvement. This single-center, retrospective CMR study reviewed patients with clinical MYO and structurally normal hearts who underwent CMR at our institution. Young adults with normal cardiac anatomy, function, and absent LGE served as controls. MYO patients with documented troponin leak and normal global ejection fraction (EF > 50 %) were included in comparison. FT determined regional myocardial peak systolic strain (pkS) in longitudinal and circumferential distributions. T tests compared strain values between cases and controls. Receiver operating characteristic curves determined pkS values with highest sensitivity and specificity for concurrent troponin leak and LGE. FT was performed on 57 patients: 37 MYO and 20 controls. Twenty-eight cases with normal EF, and 20 control patients were included in final analysis. Nearly all cases with normal function demonstrated abnormal regional pkS (27/28, 96 %). Cases had significantly diminished pkS when compared to controls in all regions except the longitudinal 2C distribution. FT-derived longitudinal and circumferential pkS is sensitive and specific in identifying myocardial involvement, namely the presence of troponin leak and LGE. FT may be a useful adjunctive, objective measure of myocardial involvement in patients with MYO and normal LV function.
The combination of echocardiography and CT characterizes morphologic features of anomalous origin of the coronary artery more reliably than either modality alone.
The presence of myocardial late gadolinium enhancement (LGE) by cardiac magnetic resonance (CMR) imaging in concert with electrocardiography and elevated biomarkers helps support the diagnosis of acute myocarditis. Two-dimensional echocardiography is limited to global and qualitative regional function assessment and may not contribute to the diagnosis, especially in the presence of normal LV systolic function. Two-dimensional speckle-tracking (2D-STE)-derived segmental peak systolic (pkS) longitudinal strain (LS) may identify segmental myocardial involvement in myocarditis. We sought to identify an association between segmental pkS, LGE, and troponin levels in patients with myocarditis. Retrospective analysis of myocardial segmental function by 2D-STE segmental strain was compared to the presence of LGE and admission peak troponin levels in patients with acute myocarditis and preserved global LV systolic function. American Heart Association 17-segment model was used for comparison between imaging modalities. Global function was assessed by m-mode-derived shortening fraction (SF). Descriptive statistics and regression analysis were utilized. Forty-four CMRs performed to evaluate for myocarditis were identified. Of the 44, 10 patients, median age 17.5 years (14-18.5 years) and median SF 35 % (28-44 %), had paired CMR and 2D-STE data for analysis, and 161/170 segments could be analyzed by both methods for comparison. PkS LS was decreased in 51 % of segments that were positive for LGE with average pkS of -14.7 %. Segmental pkS LS abnormalities were present in all but one patient who had abnormal pkS circumferential strain. Global pkS LS was decreased in patients with myocarditis. There is a moderate correlation between decreased pkS LS and the presence of LGE by CMR, 2D-STE for myocardial involvement in acute myocarditis can serve as an useful noninvasive adjunct to the existing tests used for the diagnosis of acute myocarditis and might have a role in prognostication.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.