The Promise and Illusion of Continuous, Cuffless Blood Pressure Monitoring.

PURPOSE OF REVIEW: Blood pressure (BP) fluctuations outside of clinic are increasingly recognized for their role in the development of cardiovascular disease, syncope, and premature death and as a promising target for tailored hypertension treatment. However, current cuff-based BP devices, including home and ambulatory devices, are unable to capture the breadth of BP variability across human activities, experiences, and contexts. RECENT FINDINGS: Cuffless, wearable BP devices offer the promise of beat-to-beat, continuous, noninvasive measurement of BP during both awake and sleep periods with minimal patient inconvenience. Importantly, cuffless BP devices can characterize BP variability, allowing for the identification of patient-specific triggers of BP surges in the home environment. Unfortunately, the pace of evidence, regulation, and validation testing has lagged behind the pace of innovation and direct consumer marketing. We provide an overview of the available technologies and devices for cuffless BP monitoring, considerations for the calibration and validation of these devices, and the promise and pitfalls of the cuffless BP paradigm.

#TrendingNow: Instagram Versus Twitter Activity Among Radiation Oncology Patients and Professionals.

PURPOSE: We aimed to evaluate recent Instagram and Twitter posts to identify the primary disseminators of information related to radiation therapy on social media (health care professionals vs patients), to characterize their influencer status, and to characterize the content of this information. METHODS AND MATERIALS: Using 2 commercial hashtag analytics platforms, 1000 of the most recent eligible posts from each platform were evaluated for content, tone, and engagement, as well as user (poster) characteristics. Inclusion criteria were as follows: unique posts, written in English, relevant to human cancer treatment, and containing 1 of 11 predetermined hashtags (#radiation, #radiotherapy, #radiationtherapy, #radiationoncology, #radonc, #radiationtherapist #radiationtreatment, #medphys, #cyberknife, #radiosurgery, #protontherapy). RESULTS: Users of radiation oncology content on Instagram were primarily patients/caregivers (47%), specifically adult patients (94%) with breast cancer (53%). Patient/caregiver content was focused on patient experience (79%), with approximately half specific to radiation therapy (51%), and most patient/caregiver posts demonstrated a positive tone (86%). In contrast, Twitter content was dominated by health care professionals (53%), specifically within radiation oncology (90% of unique users). Health care professional content was focused on colleague education/research dissemination (53%), with a high proportion of posts specific to radiation therapy (95%). CONCLUSIONS: Given the disproportionate number of patients versus radiation oncology professionals active on Instagram versus Twitter, and the lack of radiation therapy-specific content on Instagram, there may be an opportunity to improve patient outreach and education by promoting the presence of radiation oncologists on Instagram.

Left ventricular geometry during unloading and the end-systolic pressure volume relationship: Measurement with a modified real-time MRI-based method in normal sheep.

The left ventricular (LV) end-systolic (ES) pressure volume relationship (ESPVR) is the cornerstone of systolic LV function analysis. We describe a 2D real-time (RT) MRI-based method (RTPVR) with separate software tools for 1) semi-automatic level set-based shape prior method (LSSPM) of the LV, 2) generation of synchronized pressure area loops and 3) calculation of the ESPVR. We used the RTPVR method to measure ventricular geometry, ES pressure area relationship (ESPAR) and ESPVR during vena cava occlusion (VCO) in normal sheep. 14 adult sheep were anesthetized and underwent measurement of LV systolic function. Ten of the 14 sheep underwent RTMRI and eight of the 14 underwent measurement with conductance catheter; 4 had both RTMRI and conductance measurements. 2D cross sectional RTMRI were performed at apex, mid-ventricle and base levels during separate VCOs. The Dice similarity coefficient was used to compare LSSPM and manual image segmentation and thus determine LSSPM accuracy. LV cross-sectional area, major and minor axis length, axis ratio, major axis orientation angle and ESPAR were measured at each LV level. ESPVR was calculated with a trapezoidal rule. The Dice similarity coefficient between LSSPM and manual segmentation by two readers was 87.31±2.51% and 88.13±3.43%. All cross sections became more elliptical during VCO. The major axis orientation shifted during VCO but remained in the septo-lateral direction. LV chamber obliteration at the apical level occurred during VCO in 7 of 10 sheep that underwent RTMRI. ESPAR was non-linear at all levels. Finally, ESPVR was non-linear because of apical collapse. ESPVR measured by conductance catheter (EES,Index = 2.23±0.66 mmHg/ml/m2) and RT (EES,Index = 2.31±0.31 mmHg/ml/m2) was not significantly different. LSSPM segmentation of 2D RT MRI images is accurate and allows calculation of LV geometry, ESPAR and ESPVR during VCO. In the future, RTPVR will facilitate determination of regional systolic material parameters underlying ESPVR.