Predictors of exercise-induced pulmonary hypertension in patients with asymptomatic degenerative mitral regurgitation: mechanistic insights from 2D speckle-tracking echocardiography

Presence of exercise-induced pulmonary hypertension (EIPH) in asymptomatic degenerative mitral regurgitation (DMR) determines prognosis. This study aimed to elucidate the mechanism and predictors of EIPH in asymptomatic DMR. Ninety-one consecutive asymptomatic patients with DMR who underwent exercise stress echocardiography were prospectively included. We obtained various conventional echocardiographic parameters at rest and during peak exercise, as well as left atrial (LA) function at rest using 2-dimensional speckle-tracking analysis. The 25 patients (33.3%) with EIPH were significantly older and had a greater ratio of mitral peak velocity of early filling to early diastolic mitral annular velocity during peak exercise than those without EIPH. LA strain (LAS)-s and LAS-e, indices of LA reservoir and conduit function, respectively, were significantly lower in those with EIPH than in those without EIPH. Multivariate analysis indicated that LAS-s was the only resting echocardiographic parameter that independently predicted EIPH, with a cut-off value of 26.9%. Furthermore, Kaplan-Meier curve analysis showed that symptom-free survival was markedly lower among those with reduced LAS-s. In conclusion, decreased LA reservoir function contributes to EIPH, and LAS-s at rest is a useful indicator for predicting EIPH in asymptomatic patients with DMR

THz techniques using metal mesh sensor for human skin measurement

Abstract: Metal meshes work as band-pass filters in the terahertz (THz) region with their transmission spectra acutely being affected by the refractive index of the material inside and above the metal mesh openings. We used a metal mesh for high-sensitivity observations by focusing on the "dip", i. e. a sudden change in transmittance that only appeared when the THz wave was obliquely incident onto the metal mesh. Here we report a measurement of stratum corneum to inspect the feasibility of applying the metal mesh sensor to observations of human skin

Aortic annulus displacement assessed by contrast left ventriculography during invasive coronary angiography as a predictor of adverse events

BACKGROUND: We propose the use of aortic annulus displacement (AAD) detected on contrast left ventriculography (LVG) during invasive coronary angiography as a marker of left ventricular (LV) long-axis shortening. In the present study, we aimed to investigate whether AAD is associated with adverse events in patients who underwent coronary angiography because of suspected coronary artery disease. METHODS: In this retrospective study, we evaluated the medical records of 998 consecutive patients who underwent invasive coronary angiography and LVG. LV lengths were measured from the apex to the aortic valve insertion by using LVG images. AAD (%) was calculated as [(LV end-diastolic length-LV end-systolic length)/LV end-diastolic length]×100. RESULTS: The participants' median age was 67 years. Ninety-six adverse events (composite events; all-cause death, 39; congestive heart failure, 21; late revascularization, 34; and myocardial infarction, 2) were observed during a median follow-up period of 3.1 years. In multivariate Cox regression analysis, adverse events were associated with lower AAD (hazard ratio, 0.703; p=0.002), after adjusting for traditional risk factors and coronary artery stenosis. The area under the curve of AAD for predicting adverse events was greater than that of LV ejection fraction (0.656 vs. 0.541, p<0.05). CONCLUSIONS: AAD was superior to LV ejection fraction as a predictor of adverse events in patients with and without coronary arterial stenosis. AAD may be the optimal method for assessing longitudinal LV systolic function in the catheter laboratory

Prognostic value of exercise left ventricular end-systolic volume index in patients with asymptomatic aortic regurgitation an exercise echocardiography study

BACKGROUND: Surgical timing of chronic aortic regurgitation (AR) remains a matter of debate because of limited data. This study assessed the prognostic value of exercise echocardiography in asymptomatic AR. METHODS: This prospective study included 60 consecutive asymptomatic patients with isolated moderate or severe AR (mean regurgitant volume 56.7 ± 11.8 ml) and preserved ejection fraction who underwent exercise echocardiography. The clinical outcomes were defined by the presence of major adverse cardiovascular events (MACE) and the indication for aortic valve replacement (AVR) with class I or IIa classification in the current guidelines. RESULTS: During the average follow-up of 731 days, 12 patients suffered from the clinical events, including two patients developing MACE (3%) and ten patients indicating for AVR (17%). No difference in left ventricular (LV) ejection fraction at rest was found between the patients with and without the clinical events. The indexed LV diameters and LV volumes were significantly dilated in the patients with the clinical events. The Cox proportional hazards regression analysis resulted that the exercise LV end-systolic volume index (LVESVi) was significantly associated with the clinical outcomes [hazard ratio, 1.116; 95% CI (1.032-1.205); p = 0.006]. The Kaplan-Meier analysis showed that exercise LVESVi was clearly stratified the event-free survival. CONCLUSIONS: Exercise LVESVi might be an independent predictor of prognosis in patients with asymptomatic moderate or severe AR

Molecular Evolution of the RNA-Dependent RNA Polymerase and Capsid Genes of Human Norovirus Genotype GII.2 in Japan during 2004–2015

The RNA-dependent RNA polymerase (RdRp) and capsid (VP1) genes of 51 GII.2 human norovirus (HuNoV) strains collected during the period of 2004–2015 in Japan were analyzed. Full-length analyses of the genes were performed using next-generation sequencing. Based on the gene sequences, we constructed the time-scale evolutionary trees by Bayesian Markov chain Monte Carlo methods. Time-scale phylogenies showed that the RdRp and VP1 genes evolved uniquely and independently. Four genotypes of GII.2 (major types: GII.P2-GII.2 and GII.P16-GII.2) were detected. A common ancestor of the GII.2 VP1 gene existed until about 1956. The evolutionary rates of the genes were high (over 10−3 substitutions/site/year). Moreover, the VP1 gene evolution may depend on the RdRp gene. Based on these results, we hypothesized that transfer of the RdRp gene accelerated the VP1 gene evolution of HuNoV genotype GII.2. Consequently, recombination between ORF1 (polymerase) and ORF2 (capsid) might promote changes of GII.2 antigenicity