Non-invasive assessment of left ventricular filling pressure in aortic stenosis.

BACKGROUND: The assessment of left ventricular (LV) filling pressure (FP) is important for the management of aortic stenosis (AS) patients. Although, it is often restricted for predict LV FP in AS because of mitral annular calcification and a certain left ventricular hypertrophy. Thus, we tested the predictive ability of the algorithm for elevated LV FP in AS patients and also applied a recently-proposed echocardiographic scoring system of LV FP, visually assessed time difference between the mitral valve and tricuspid valve opening (VMT) score. METHODS: We enrolled consecutive 116 patients with at least moderate AS in sinus rhythm who underwent right heart catheterization and echocardiography within 7 days. Mean pulmonary artery wedge pressure (PAWP) was measured as invasive parameter of LV FP. LV diastolic dysfunction (DD) was graded according to the ASE/EACVI guidelines. The VMT score was defined as follows: time sequence of opening of mitral and tricuspid valves was scored to 0-2 (0: tricuspid valve first, 1: simultaneous, 2: mitral valve first). When the inferior vena cava was dilated, one point was added and VMT score was finally calculated as 0-3. RESULTS: Of the 116 patients, 29 patients showed elevated PAWP. Ninety patients (93%) and 67 patients (63%) showed increased values for left atrium volume index (LAVI) and E/e', respectively when the cut-off values recommended by the guidelines were applied and thus the algorism predicted elevated PAWP with a low specificity and positive predictive value (PPV). VMT ≥ 2 predicted elevated PAWP with a sensitivity of 59%, specificity of 90%, PPV of 59%, and negative predictive value of 89%. An alternative algorithm that applied tricuspid regurgitation velocity and VMT scores was tested, and its predictive ability was markedly improved. CONCLUSION: VMT score was applicable for AS patients. Alternative use of VMT score improved diagnostic accuracy of guideline-recommended algorism.

Echocardiographic estimation of right ventricular diastolic stiffness based on pulmonary regurgitant velocity waveform analysis in precapillary pulmonary hypertension.

Right ventricular (RV) diastolic stiffness is an independent predictor of survival and is strongly associated with disease severity in patients with precapillary pulmonary hypertension (PH). Therefore, a fully validated echocardiographic method for assessing RV diastolic stiffness needs to be established. This study aimed to compare echocardiography-derived RV diastolic stiffness and invasively measured pressure-volume loop-derived RV diastolic stiffness in patients with precapillary PH. We studied 50 consecutive patients with suspected or confirmed precapillary PH who underwent cardiac catheterization, magnetic resonance imaging, and echocardiography within a 1-week interval. Single-beat RV pressure-volume analysis was performed to determine the gold standard for RV diastolic stiffness. Elevated RV end-diastolic pressure (RVEDP) was defined as RVEDP ≥ 8 mmHg. Using continuous-wave Doppler and M-mode echocardiography, an echocardiographic index of RV diastolic stiffness was calculated as the ratio of the atrial-systolic descent of the pulmonary artery-RV pressure gradient derived from pulmonary regurgitant velocity (PRPGDAC) to the tricuspid annular plane movement during atrial contraction (TAPMAC). PRPGDAC/TAPMAC showed significant correlation with ß (r = 0.54, p < 0.001) and RVEDP (r = 0.61, p < 0.001). A cut-off value of 0.74 mmHg/mm for PRPGDAC/TAPMAC showed 83% sensitivity and 93% specificity for identifying elevated RVEDP. Multivariate analyses indicated that PRPGDAC/TAPMAC was independently associated with disease severity in patients with precapillary PH, including substantial PH symptoms, stroke volume index, right atrial size, and pressure. PRPGDAC/TAPMAC, based on pulmonary regurgitation velocity waveform analysis, is useful for the noninvasive assessment of RV diastolic stiffness and is associated with prognostic risk factors in precapillary PH.

Application of an echocardiographic scoring system of left ventricular filling pressure to diagnose acute heart failure in patients complaining dyspnea.

BACKGROUND: Dyspnea is a common symptom in acute heart failure (AHF) patients. Although an accurate and rapid diagnosis of AHF is essential to improve prognosis, estimation of left ventricular (LV) filling pressure (FP) remains challenging, especially for noncardiologists. We evaluated the usefulness of a recently-proposed parameter of LV FP, visually assessed time difference between the mitral valve and tricuspid valve opening (VMT) score, to detect AHF in patients complaining of dyspnea. METHODS: Echocardiography and lung ultrasonography (LUS) were performed in 121 consecutive patients (68 ±â€¯14 years old, 75 males) presenting with dyspnea. The VMT score was determined from the atrioventricular valve opening phase (tricuspid valve first: 0, simultaneous: 1, mitral valve first: 2) and inferior vena cava dilatation (absent: 0, present: 1), and VMT ≥2 was judged as positive. LUS was performed with the 8 zones method and judged as positive if 3 or more B-lines were observed in bilateral regions. The AHF diagnosis was performed by certified cardiologists according to recent guidelines. RESULTS: Of the 121 patients, 33 were diagnosed with AHF. The sensitivity and specificity for diagnosing AHF were 64 % and 84 % for LUS and 94 % and 88 % for VMT score. In logistic regression analysis, VMT score showed a significantly higher c-index than LUS (0.91 vs 0.74, p = 0.002). In multivariable analyses, VMT score was associated with AHF independently of clinically relevant covariates and LUS. In addition, serial assessment of VMT score followed by LUS provided a diagnostic flow chart to diagnose AHF (VMT 3: AHF definitive, VMT 2 and LUS positive: AHF highly suspicious; VMT 2 and LUS negative: further investigation is needed; VMT ≤ 1: AHF rejected). CONCLUSIONS: VMT score showed high diagnostic accuracy in diagnosing AHF. Combined assessment of the VMT score and LUS could become a reliable strategy for diagnosis of AHF by non-cardiologists.

Effects of Intermittent and Continuous Static Stretching on Range of Motion and Musculotendinous Viscoelastic Properties Based on a Duration-Matched Protocol.

The different effects of intermittent and continuous stretching on the mechanical properties of the musculotendinous complex have been unclear. This study aimed to compare the effects of intermittent and continuous stretching for the same duration on the range of motion (ROM), passive resistive torque (PRT), and musculotendinous stiffness (MTS) of ankle plantar flexors. Eighteen healthy young men participated in the study. Intermittent (four sets × 30 s) and continuous stretching (one set × 120 s) were performed in random orders on two separate days. Both stretching protocols were conducted using a dynamometer with a constant torque applied. ROM and PRT were determined using a dynamometer, and MTS was calculated using the torque-angle relationship measured before and after stretching. Two-way repeated measures analysis of variance was performed for all parameters. Both intermittent and continuous stretching significantly increased ROM and decreased PRT and MTS (p < 0.05). Intermittent stretching led to greater changes in ROM and PRT than continuous stretching. However, the reduction in MTS did not differ between the two conditions. These results suggest that intermittent stretching is more effective in increasing ROM and changing the mechanical properties of the musculotendinous complex.

Direct Visualization of the Two-step Nucleation Model by Fluorescence Color Changes during Evaporative Crystallization from Solution.

The two-step nucleation model for crystal nuclei formation explains several experimental and theoretical results better than the classical nucleation theory. We report here direct visualization of the two-step nucleation model for organic molecular crystallization. Evaporative crystallization from a solution of a dibenzoylmethane boron complex that displays mechanofluorochromism, a fluorescence color change induced by mechanical perturbation, was probed by fluorescence change. The dependence of fluorescence change on dispersion concentration of the complex in a polymer matrix was also investigated. We detected transitional emission from the amorphous cluster state prior to crystallization. This is the first demonstration of the two-step nucleation model based on fluorescence color changes.

Involvement of autocrine CXCL12/CXCR4 system in the regulation of ovarian carcinoma cell invasion.

Ovarian carcinomas are often highly invasive, especially in the peritoneal cavity; however, the mechanism involved in invasion is not yet fully understood. In the present research, we studied the role of NF-κB in the invasiveness of ovarian carcinoma cells by using (-)-DHMEQ, a specific inhibitor of NF-κB. (-)-DHMEQ inhibited invasion in vitro and the expression of CXCL12 and CXCR4. We found that neutralizing antibody against CXCR4 or knockdown of CXCR4 suppressed the invasion. Proteomic analysis revealed that CXCR4-siRNA treatment lowered the secretion of several invasion-related proteins, such as MMP-9 and uPA. These data imply that (-)-DHMEQ suppressed ovarian cell invasion via inhibition of the NF-κB-regulated autocrine system of CXCL12-CXCR4.