Background: Remote dielectric sensing (ReDS™) is an electromagnetic-based technology used to noninvasively measure lung fluid levels. The association between ReDS values and invasively measured hemodynamics, particularly among those with small physics, remains unknown. Methods: Consecutive patients with chronic heart failure who were admitted to our institute and underwent invasive right heart catheterization as well as simultaneous ReDS measurement at clinically stable conditions between September and November 2021 were prospectively included. The colinearity between ReDS values and pulmonary capillary wedge pressure was studied. Results: In total, 30 patients (median 79 (73, 84) years old, 13 men) were included. Median ReDS value was 26% (22%, 28%). ReDS values had a moderate collinearity with pulmonary capillary wedge pressure (r = 0.698, p < 0.001), even among those with a body height < 155 cm. ReDS values with a cutoff of 28% predicted a pulmonary capillary wedge pressure > 15 mmHg with sensitivity 0.70 and specificity 0.75. Conclusions: An electromagnetic-based engineering ReDS might be a potential tool to estimate cardiac pressure in patients with heart failure, including those with small physics.

Background: The accuracy of the remote dielectric sensing (ReDS^TM) system, which is a noninvasive electromagnetic-based technology to quantify lung fluid levels, particularly among those with small body size, remains uncertain. Methods: Hospitalized patients with and without heart failure underwent assessment of lung fluid levels with ReDS and successive chest computed tomography imaging. We performed a correlation analysis of the ReDS measurement, representing lung fluid levels, and computed tomography-derived high attenuation area percentage, which also provides a spatial quantification of lung fluid level. Results: A total of 46 patients (median 76 years old, 28 men), including 28 patients with heart failure, were included. The median ReDS value was 28% (interquartile: 23%, 33%), and the median percentage of high attenuation area was 21.6% (14.4%, 28.5%). ReDS values and percentage of high attenuation area were moderately correlated (r = 0.65, p < 0.001), irrespective of the existence of heart failure. ReDS value independently predicted the percentage of high attenuation area seen on computed tomography (p < 0.001). Conclusions: The ReDS system may be a promising, noninvasive tool to quantify fluid lung levels, as validated by comparison with chest computed tomography imaging. Further studies are warranted to validate the utility and applicability of this technology to a variety of clinical scenarios.

We found that pediatricians have enhanced specific cellular immunity to varicella-zoster virus (VZV) compared with the general population, which may be due to reexposure to VZV from children with chickenpox. There have been some reported that the varicella vaccine enhance the specific cellular immunity. To estimate the efficacy of varicella vaccine for protection against herpes zoster in the elderly, we investigated the incidence of herpes zoster in 500 pediatricians and family practitioners with their fifties and sixties, and history of reexposure to VZV in 61 patients with herpes zoster by questionnaires retrospectively. Thirty-four of 352 pediatricians had a past history of herpes zoster. The incidence per 100,000 person-years of herpes zoster was 65.2 in those in their fifties and 158.2 in those in their sixties, which are 1/2 to 1/8 of other reports regarding the general population. Among 61 immunocompetent patients with herpes zoster, only 4 patients (6.6%) had the chance for reexpose to VZV before their herpes zoster. Only 7 (17.5%) of the 40 patients older than 50 years of age lived with their children less than 14 years of age. Twenty-three (57.5%) of them lived without their children and grandchildren. They are thought to be less chance to reexpose to VZV through children. We may think that the booster effect by reexposure to VZV plays an important role to prevent herpes zoster. Therefore, we can speculate that the varicella vaccine may protect against herpes zoster in the elderly by the enhanced specific cellular immunity due to the booster effect.