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Photodamage is caused by chronic sun exposure and ultraviolet radiation and presents as wrinkles, sagging, and pigmented spots. An increase in the ultraviolet index can increase a person's perceived age by worsening skin photodamage. However, since the ultraviolet index varies considerably between geographical regions, perceived age might vary substantially among them. This review aims to describe the differences in chronological and perceived age in regions of the world with different ultraviolet indexes. A literature search of three databases was conducted for studies analyzing perceived age and its relationship to sun exposure. Ultraviolet indexes from the included studies were retrieved from the National Weather Service and the Tropospheric Emission Monitoring Internet Service. Out of 104 studies, seven fulfilled the inclusion criteria. Overall, 3,352 patients were evaluated for perceived age. All studies found that patients with the highest daily sun exposures had the highest perceived ages for their chronological age (p

The number of applications for facial recognition technology is increasing due to the improvement in image quality, artificial intelligence, and computer processing power that has occurred during the last decades. Algorithms can be used to convert facial anthropometric landmarks into a computer representation, which can be used to help identify nonverbal information about an individual's health status. This article discusses the potential ways a facial recognition tool can perform a health assessment. Because facial attributes may be considered biometric data, clinicians should be informed about the clinical, ethical, and legal issues associated with its use.

Wearable electronic devices are a convenient solution to pain intensity assessment as they can provide continuous monitoring for more precise medication adjustments. However, there is little evidence regarding the use of wearable electronic devices for chronic pain intensity assessment. Our primary objective was to examine the physiologic parameters used by wearable electronic devices for chronic pain intensity assessment. We initially inquired PubMed, CINAHL, and Embase for studies evaluating the use of wearable electronic devices for chronic pain intensity assessment. We updated our inquiry by searching on PubMed, Embase, Scopus, and Google Scholar. English peer-reviewed studies were included, with no exclusions based on time frame or publication status. Of 348 articles that were identified on the first inquiry, 8 fulfilled the eligibility criteria. Of 179 articles that were identified on the last inquiry, only 1 fulfilled the eligibility criteria. We found articles evaluating wristbands, smartwatches, and belts. Parameters evaluated were psychomotor and sleep patterns, space and time mobility, heart rate variability, and skeletal muscle electrical activity. Most of the studies found significant positive associations between physiological parameters measured by wearable electronic devices and self-reporting pain scales. Wearable electronic devices reliably reflect physiologic or biometric parameters, providing a physiological correlation for pain. Early stage investigation suggests that the degree of pain intensity can be discerned, which ideally will reduce the bias inherent to existing numeric/verbal scales. Further research on the use of these devices is vital.

Perceived age is defined as how old a person looks to external evaluators. It reflects the underlying biological age, which is a measure based on physical and physiological parameters reflecting a person's aging process more accurately than chronological age. People with a higher biological age have shorter lives compared to those with a lower biological age with the same chronological age. Our review aims to find whether increased perceived age is a risk factor for overall mortality risk or comorbidities.A literature search of three databases was conducted following the PRISMA guidelines for studies analyzing perceived age or isolated facial characteristics of old age and their relationship to mortality risk or comorbidity outcomes. Data on the number of patients, type and characteristics of evaluation methods, evaluator characteristics, mean chronologic age, facial characteristics studied, measured outcomes, and study results were collected.Out of 977 studies, 15 fulfilled the inclusion criteria. These studies found an increase in mortality risk of 6-51% in older-looking people compared to controls (HR 1.06-1.51, p0.05). In addition, perceived age and some facial characteristics of old age were also associated with cardiovascular risk and myocardial infarction, cognitive function, bone mineral density, and chronic obstructive pulmonary disease (COPD).Perceived age promises to be a clinically useful predictor of overall mortality and cardiovascular, pulmonary, cognitive, and osseous comorbidities.This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Pain assessment is a complex task largely dependent on the patient’s self-report. Artificial intelligence (AI) has emerged as a promising tool for automating and objectifying pain assessment through the identification of pain-related facial expressions. However, the capabilities and potential of AI in clinical settings are still largely unknown to many medical professionals. In this literature review, we present a conceptual understanding of the application of AI to detect pain through facial expressions. We provide an overview of the current state of the art as well as the technical foundations of AI/ML techniques used in pain detection. We highlight the ethical challenges and the limitations associated with the use of AI in pain detection, such as the scarcity of databases, confounding factors, and medical conditions that affect the shape and mobility of the face. The review also highlights the potential impact of AI on pain assessment in clinical practice and lays the groundwork for further study in this area.

Pain is a complex and subjective experience, and traditional methods of pain assessment can be limited by factors such as self-report bias and observer variability. Voice is frequently used to evaluate pain, occasionally in conjunction with other behaviors such as facial gestures. Compared to facial emotions, there is less available evidence linking pain with voice. This literature review synthesizes the current state of research on the use of voice recognition and voice analysis for pain detection in adults, with a specific focus on the role of artificial intelligence (AI) and machine learning (ML) techniques. We describe the previous works on pain recognition using voice and highlight the different approaches to voice as a tool for pain detection, such as a human effect or biosignal. Overall, studies have shown that AI-based voice analysis can be an effective tool for pain detection in adult patients with various types of pain, including chronic and acute pain. We highlight the high accuracy of the ML-based approaches used in studies and their limitations in terms of generalizability due to factors such as the nature of the pain and patient population characteristics. However, there are still potential challenges, such as the need for large datasets and the risk of bias in training models, which warrant further research.

Unnecessary ED visits and transfers to hand clinics raise treatment costs and patient burden at trauma centers. In the present COVID-19 pandemic, needless transfers can increase patients’ risk of viral exposure. Therefore, this review analyzes different aspects of the remote diagnosis and triage of traumatic hand injuries. The most common file was photography, with the most common devices being cell phone cameras. Treatment, triage, diagnosis, cost, and time outcomes were assessed, showing concordance between teleconsultation and face-to-face patient evaluations. We conclude that photography and video consultations are feasible surrogates for ED visits in patients with traumatic hand injuries. These technologies should be leveraged to decrease treatment costs and potentially decrease the time to definitive treatment after initial evaluation.

The number of applications for facial recognition technology is increasing due to the improvement in image quality, artificial intelligence, and computer processing power that has occurred during the last decades. Algorithms can be used to convert facial anthropometric landmarks into a computer representation, which can be used to help identify nonverbal information about an individual's health status. This article discusses the potential ways a facial recognition tool can perform a health assessment. Because facial attributes may be considered biometric data, clinicians should be informed about the clinical, ethical, and legal issues associated with its use.

Background Wearable devices and sensor technology provide objective, unbiased range of motion measurements that help health care professionals overcome the hindrances of protractor-based goniometry. This review aims to analyze the accuracy of existing wearable sensor technologies for hand range of motion measurement and identify the most accurate one. Methods We performed a systematic review by searching PubMed, CINAHL, and Embase for studies evaluating wearable sensor technology in hand range of motion assessment. Keywords used for the inquiry were related to wearable devices and hand goniometry. Results Of the 71 studies, 11 met the inclusion criteria. Ten studies evaluated gloves and 1 evaluated a wristband. The most common types of sensors used were bend sensors, followed by inertial sensors, Hall effect sensors, and magnetometers. Most studies compared wearable devices with manual goniometry, achieving optimal accuracy. Although most of the devices reached adequate levels of measurement error, accuracy evaluation in the reviewed studies might be subject to bias owing to the use of poorly reliable measurement techniques for comparison of the devices. Conclusion Gloves using inertial sensors were the most accurate. Future studies should use different comparison techniques, such as infrared camera–based goniometry or virtual motion tracking, to evaluate the performance of wearable devices.

Introduction Patients discharged after acute decompensated heart failure (ADHF) have elevated risk for readmission due to multiple factors including suboptimal behavioral and social support. Telemonitoring interventions have shown inconsistent effectiveness in reducing HF readmissions. Patient-centered health coaching, when combined with telemonitoring, may be a viable model to engage patients in self-care behaviors and enhance patient experiences following acute hospitalization. Purpose This multicenter randomized trial evaluates whether remote telemonitoring combined with health coaching decreases 60 day readmission rates for patients with ADHF when compared to standard of care. Methods Patients with primary or secondary diagnosis of ADHF were consented and randomized prior to hospital discharge to either standard care or intervention of remote telemonitoring and health coaching. Within 2 days of hospital dismissal, intervention patients were onboarded to the remote monitoring platform, which links personal health sensors which collect on-body physiologic measures (ECG, heart rate, respiration rate, and activity via 3-axis accelerometer) with providers through secure mobile communication. A registered nurse was designated as the primary health coach focusing on disease management - including symptom recognition, adherence to treatment strategies, care coordination, medication matters, and problem solving. A social worker and nutritionist were also assigned. The primary outcome was all-cause mortality or readmission within 60 days of hospital dismissal. Statistical analysis included stratified log-rank tests and stratified Cochran-Mantel-Haenszel Chi-square test to account for site-stratified randomization. Results The study was halted due to low rate of subject accrual. Of planned 304 subjects, 143 were randomized between 2015 and 2019 at 6 sites in the United States. Dropout and withdrawal after randomization of 32 subjects (22%) left 112 analyzable for the primary endpoint. Many subject withdrawals after unblinded disclosure of arm allocation were related to treatment assignment. Immediate withdrawal without follow up in these subjects precluded an intention-to-treat analysis. Mean age was 69 years and subjects were more often male (56%) and non-Hispanic white (70%). In per-protocol analysis, using subjects adherent to protocol specified visits (n=112), we observe no difference in the primary outcome (26% among intervention vs 28% among standard care, Figure, p=0.77). There were also no differences among secondary outcomes of overall mortality (2% vs 7%, p=0.20) or composite emergency department visit, hospital admission, or death (35% vs 34%, p=0.85). Conclusions Among patients with heart failure, an intervention of remote telemonitoring and health coaching did not reduce all-cause readmission or mortality. Significant withdrawal rates suggest future studies may need to improve screening and study retention. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health, National Institute on Aging

Produced by senescent cells, the senescence-associated secretory phenotype (SASP) is a potential driver of age-related dysfunction. We tested whether circulating concentrations of SASP proteins reflect age and medical risk in humans. We first screened senescent endothelial cells, fibroblasts, preadipocytes, epithelial cells, and myoblasts to identify candidates for human profiling. We then tested associations between circulating SASP proteins and clinical data from individuals throughout the life span and older adults undergoing surgery for prevalent but distinct age-related diseases. A community-based sample of people aged 20–90 years (retrospective cross-sectional) was studied to test associations between circulating SASP factors and chronological age. A subset of this cohort aged 60–90 years and separate cohorts of older adults undergoing surgery for severe aortic stenosis (prospective longitudinal) or ovarian cancer (prospective case-control) were studied to assess relationships between circulating concentrations of SASP proteins and biological age (determined by the accumulation of age-related health deficits) and/or postsurgical outcomes. We showed that SASP proteins were positively associated with age, frailty, and adverse postsurgery outcomes. A panel of 7 SASP factors composed of growth differentiation factor 15 (GDF15), TNF receptor superfamily member 6 (FAS), osteopontin (OPN), TNF receptor 1 (TNFR1), ACTIVIN A, chemokine (C-C motif) ligand 3 (CCL3), and IL-15 predicted adverse events markedly better than a single SASP protein or age. Our findings suggest that the circulating SASP may serve as a clinically useful candidate biomarker of age-related health and a powerful tool for interventional human studies.

Remote monitoring has the potential to improve patient care and satisfaction while reducing the cost of care and burden on the healthcare system for Congestive Heart Failure (CHF) and Atrial Fibrillation (AF) patients. However, the device must be convenient and easy for the population to use correctly. In this study, human factors and qualitative researchers evaluated the use of a remote cardiac monitoring device during a clinical trial with 74 CHF and AF patients. Human factors usability concerns centered on device use and the information presented in the manual. The key themes identified during the qualitative analysis were related to patient education. These findings were incorporated into device design, user manual, or education material updates. This study illustrates how these methods can infuse patient experience into device design to inform continued quality improvement and usability refinement specifically in devices to aid CHF and AF patients without added burden.

Objectives We aimed to develop a percutaneous defibrillation system with partially insulated epicardial coils to focus electrical energy on the myocardium and prevent or minimize extracardiac stimulation. Background Epicardial defibrillation systems currently require surgical access. Methods We tested 2 prototypes created for percutaneous introduction into the pericardial space via a steerable sheath. This testing included a partially insulated defibrillation coil and a defibrillation mesh with a urethane balloon acting as an insulator to the face of the mesh not in contact with the epicardium. The average energy associated with a chance of successful defibrillation 75% of the time was calculated for each experiment. Results Of 16 animal experiments, 3 pig experiments had malfunctioning mesh prototypes such that results were unreliable; these were excluded. Therefore, 13 animal experiments were analyzed, 6 in canines (29.8 ± 4.0 kg) and 7 in pigs (41.1 ± 4.4 kg). The overall chance of successful defibrillation 75% of the time was 12.8 ± 6.7 J (10.9 ± 9.1 J for canines and 14.4 ± 3.9 J in pigs; p = 0.37). The lowest chance of successful defibrillation 75% of the time obtained in canines was 2.5 J, whereas in pigs it was 9.5 J. The lowest energy resulting in successful defibrillation was 2 J in canines and 5 J in pigs. There was no evidence of coronary vessel injury or trauma to extrapericardial structures. Conclusions Percutaneous, epicardial defibrillation using a partially insulated coil is feasible and seems to be associated with low defibrillation thresholds. Focusing insulation may limit extracardiac stimulation and potentially lower energy requirements for efficient defibrillation.

Background Frailty confers risk for surgical morbidity and mortality. Whether patient-reported measures of health, well-being, or quality of life respond differently to surgery in non-frail and frail individuals is unknown. Methods Older adults with severe aortic stenosis presenting for surgery were assessed for frailty using Cardiovascular Health Study Criteria. Patient-reported measures of functional capacity (Duke Activity Status Index [DASI]), physical and mental health (Medical Outcomes Study Short Form-Physical and Mental Component Scales [SF-12 PCS and SF-12 MCS, respectively]), well-being (linear analogue self-assessment [LASA]), and quality of life (LASA) were administered before and 3 months after surgery. Results Of 103 participants (mean age of 80.6 years), 54 were frail. Frail participants had lower baseline DASI, SF-12 PCS, SF-12 MCS, physical well-being, and quality of life scores than non-frail participants. At follow-up, frail participants showed significant improvement in physical function, with DASI and SF-12 PCS scores improving by 50% and 14%, respectively. Non-frail subjects did not significantly improve in these measures. SF-12 MCS scores also improved to a greater extent in frail compared to non-frail participants (3.6 vs < 1 point). Furthermore, the frail participants improved to a greater extent than non-frail participants in physical well-being (21.6 vs 7.1 points) and quality of life measures (25.1 vs 8.7 points). Conclusions Frailty is prevalent in older adults with severe aortic stenosis and is associated with poor physical and mental function, physical well-being, and quality of life. In response to surgery, frail participants exhibited greater improvement in these patient-centered outcomes than non-frail peers.

Androgenic alopecia (AGA) is a common hair loss disorder. Studies have demonstrated successful treatment with platelet-rich plasma (PRP) in men, but studies in women are few.To evaluate PRP in the treatment of AGA in women, compared with topical minoxidil.Twenty women with AGA received topical minoxidil for 12 weeks and injectable PRP for 12 weeks in a randomized crossover design with an 8-week washout between treatments. Standardized TrichoScan analysis and quality-of-life questionnaires were assessed at baseline and 12-week follow-up for each treatment.After PRP, significant increases from baseline to Week 12 in TrichoScan analysis hair count (p = .002) and vellus hair density (p = .009) occurred. However, minoxidil resulted in significant increases in hair count (p.001), vellus hair density (p = .03), terminal hair density (p = .004), and cumulative thickness (p = .004). Several quality of life responses improved from baseline to Week 12 after PRP treatment, whereas no improvements were noted after minoxidil.Platelet-rich plasma is an effective treatment for hair regrowth in female AGA, although not as effective as minoxidil. However, the improved quality of life responses after PRP, but not minoxidil, suggest a potential overall greater degree of satisfaction with PRP.I.NCT03488108.

BACKGROUND Echocardiographically detected patent foramen ovale (PFO) has been associated with stroke/transient ischemic attack (TIA) in patients with cardiac implantable electronic devices (CIEDs). We sought to evaluate the relationship between echocardiographic characteristics and risk of stroke/TIA and mortality in CIED patients with PFO. METHODS In 6,086 device patients, PFO was detected in 319 patients. A baseline echocardiogram was present in 250 patients, with 186 having a follow-up echocardiogram. RESULTS Of 250 patients with a baseline echocardiogram, 9.6% (n = 24) had a stroke/TIA during mean follow-up of 5.3 ± 3.1 years; and 42% (n = 105) died over 7.1 ± 3.7 years. Atrial septal aneurysm, prominent Eustachian valve, visible shunting across PFO, baseline or change in estimated right ventricular systolic pressure (RVSP)/tricuspid regurgitation (TR), or maximum RVSP were not associated with postimplant stroke/TIA (P > 0.05). An exploratory multivariate analysis using time-dependent Cox models showed increased hazard of death in patients with increase in TR ≥2 grades (hazard ratio [HR] 1.780, 95% confidence interval [CI] 1.447-2.189, P 10 mm Hg (HR 2.018, 95% CI 1.593-2.556, P < 0.0001), or maximum RVSP in follow-up (HR 1.432, 95% CI 1.351-1.516, P < 0.0001). A significant increase (P < 0.001) in TR was also noted during follow-up. CONCLUSIONS In patients with CIED and PFO, structural and hemodynamic echocardiographic markers did not predict future stroke/TIA. However, a significantly higher TR or RVSP was associated with higher mortality.

BACKGROUND Automated external defibrillators can provide life-saving therapies to treat ventricular fibrillation. We developed a prototype unit that can deliver a unique shock waveform produced by four independent capacitors that is delivered through two shock vectors, with the rationale of providing more robust shock pathways during emergent defibrillation. We describe the initial testing and feasibility of this unique defibrillation unit, features of which may enable downsizing of current defibrillator devices. METHODS We tested our defibrillation unit in four large animal models (two canine and two swine) under general anesthesia. Experimental defibrillation thresholds (DFT) were obtained by delivery of a unique waveform shock pulse via a dual-vector pathway with four defibrillation pads (placed across the chest). DFTs were measured and compared with those of a commercially available biphasic defibrillator (Zoll M series, Zoll Medical, Chelmsford, MA, USA) tested in two different vectors. Shocks were delivered after 10 seconds of stable ventricular fibrillation and the output characteristics and shock outcome recorded. Each defibrillation series used a step-down to failure protocol to define the defibrillation threshold. RESULTS A total of 96 shocks were delivered during ventricular fibrillation in four large animals. In comparison to the Zoll M series, which delivered a single-vector, biphasic shock, the energy required for successful defibrillation using the unique dual-vector biphasic waveform did not differ significantly (P = 0.65). CONCLUSIONS Our early findings support the feasibility of a unique external defibrillation unit using a dual-vector biphasic waveform approach. This warrants further study to leverage this unique concept and work toward a miniaturized, portable shock delivery system.

Background Papillary fibroelastomas (PFE) are benign neoplasms with little available outcome data. Objectives This study sought to describe the frequency and clinical course of patients with surgically removed PFE and echocardiographically suspected, but unoperated, PFE. Methods Mayo Clinic pathology and echocardiography databases (January 1, 1995, to December 31, 2010) were queried, resulting in 511 patients: group 1 (n = 185), including patients with surgically removed, histopathologically confirmed PFE; group 1a (n = 94; 51%) with PFE removed at primary surgery; and group 1b (n = 91; 49%) with PFE removal at time of another cardiac surgery. Group 2 (n = 326) patients had echocardiographic evidence of PFE but no cardiac surgery to remove PFE. Results Group 1 had mean age of 63 ± 14 years (116 women [63%]). During the study period, we identified 112 cardiac myxomas in the pathology database and 142 in the echocardiographic database. Mean age in group 2 was 67 ± 14 years (162 women [50%]). PFE occurred most commonly on cardiac valves (n = 400 [78%]). In group 1, transient ischemic attack or stroke was the presenting symptom in 58 patients (32%). With surgical removal of valvular PFE, the valve was preserved in 92 (98%). Recurrence was documented in 3 patients (1.6%). Follow-up stroke risk in groups 1, 1a, and 1b at 1 year was 2%, 0%, and 4%; at 5 years, 8%, 5%, and 11%, respectively. Cerebrovascular accident risk in group 2 at 1 and 5 years was 6% and 13%. Conclusions In patients with echocardiographically suspected PFE who do not undergo surgical removal, rates of cerebrovascular accident and mortality are increased.

Background Cardiac implantable electronic devices (CIEDs) are commonly associated with transvenous lead-related thrombi that can cause pulmonary embolism (PE). Methods and results We retrospectively evaluated all patients with transvenous CIED leads implanted at Mayo Clinic Rochester between 1 January 2000, and 25 October 2010. Pulmonary embolism outcomes during follow-up were screened using diagnosis codes and confirmed with imaging study reports. Of 5646 CIED patients (age 67.3 ± 16.3 years, 64% men, mean follow-up 4.69 years) 88 developed PE (1.6%), incidence 3.32 [95% confidence interval (CI) 2.68–4.07] per 1000 person-years [men: 3.04 (95% CI 2.29–3.96) per 1000 person-years; women: 3.81 (95% CI 2.72–5.20) per 1000 person-years]. Other than transvenous CIED lead(s), 84% had another established risk factor for PE such as deep vein thrombosis (28%), recent surgery (27%), malignancy (25%), or prior history of venous thromboembolism (15%). At the time of PE, 22% had been hospitalized for ≥48 h, and 59% had been hospitalized in the preceding 30 days. Pulmonary embolism occurred in 22% despite being on systemic anticoagulation therapy. Out of 88 patients with PE, 45 subsequently died, mortality rate 93 (95% CI 67–123) per 1000 person-years (hazard ratio 2.0, 95% CI 1.5–2.7, P < 0.0001). Conclusions Though lead-related thrombus is commonly seen in patients with transvenous CIED leads, clinical PE occurs with a low incidence. It is possible that embolism of lead thrombus is uncommon or emboli are too small to cause consequential pulmonary infarction.

To demonstrate the feasibility of directional percutaneous epicardial ablation using a partially insulated catheter. Partially insulated catheter prototypes were tested in 12 (6 canine, 6 porcine) animal studies in two centers. Prototypes had interspersed windows to enable visualization of epicardial structures with ultrasound. Epicardial unipolar ablation and ablation between two electrodes was performed according to protocol (5–60 W power, 0–60 mls/min irrigation, 78 s mean duration). Of 96 epicardial ablation attempts, unipolar ablation was delivered in 53.1%. Electrogram evidence of ablation, when analyzable, occurred in 75 of 79 (94.9%) therapies. Paired pre/post-ablation pacing threshold (N = 74) showed significant increase in pacing threshold post-ablation (0.9 to 2.6 mA, P

To determine if ECG repolarization measures can be used to detect small changes in serum potassium levels in hemodialysis patients.Signal-averaged ECGs were obtained from standard ECG leads in 12 patients before, during, and after dialysis. Based on physiological considerations, five repolarization-related ECG measures were chosen and automatically extracted for analysis: the slope of the T wave downstroke (T right slope), the amplitude of the T wave (T amplitude), the center of gravity (COG) of the T wave (T COG), the ratio of the amplitude of the T wave to amplitude of the R wave (T/R amplitude), and the center of gravity of the last 25% of the area under the T wave curve (T4 COG) (Fig. 1).The correlations with potassium were statistically significant for T right slope (P0.0001), T COG (P=0.007), T amplitude (P=0.0006) and T/R amplitude (P=0.03), but not T4 COG (P=0.13). Potassium changes as small as 0.2mmol/L were detectable.Small changes in blood potassium concentrations, within the normal range, resulted in quantifiable changes in the processed, signal-averaged ECG. This indicates that non-invasive, ECG-based potassium measurement is feasible and suggests that continuous or remote monitoring systems could be developed to detect early potassium deviations among high-risk patients, such as those with cardiovascular and renal diseases. The results of this feasibility study will need to be further confirmed in a larger cohort of patients.

Objective Functional tricuspid regurgitation (TR) is recognized as a significant cause of morbidity and mortality in cardiothoracic surgery. We hypothesized that a variably expandable, transvalvular balloon mounted on a catheter could be percutaneously inserted and fixed to the right ventricle apex. This novel approach could provide a minimally invasive way to eliminate clinically relevant TR caused by annular dilatation. This study was performed to test the ex vivo hemodynamic effects and the feasibility of the “balloon plug concept.” Methods Twenty harvested calf tricuspid valves were placed in a mechanical simulator. Tricuspid regurgitation was created by annular stretching and displacement of the papillary muscles so as to create central TR. A flexible catheter with a 4-cm–long, soft, fusiform balloon was positioned across the valve so that the balloon was suspended centrally across the valve annular plane. After activating the mechanical ventricle, data were collected with balloon inflation volumes of saline from 5 to 20 mL. Transvalvular pressure gradients and leaflet mechanics were evaluated with incremental inflation. Results In all cases, 5-mL inflation did not significantly reduce TR and 20-mL inflation caused obstruction to antegrade flow (mean transvalvular gradient > 4 mm Hg). Inflation between 10 and 15 mL caused significant reduction in TR with acceptable transvalvular gradients (Conclusions The balloon plug concept showed promising ex vivo hemodynamic results. In vivo investigations are warranted to evaluate percutaneous techniques, thrombogenicity, and effects of repeated balloon-leaflet contact on valve integrity.

The unique anatomic position of the pericardium in juxtaposition to central cardiac structures enables it to serve as the ideal vantage point for the delivery of novel cardiovascular therapies. Development of new tools to permit delivery of therapy in the closed pericardial space holds promise for near-surgical access to the heart, without open surgical morbidity. Early observations raise hope for the availability of epicardial leads to enhance cardiac resynchronization therapy designed for subxiphoid nonsurgical percutaneous delivery. Emerging technologies for left atrial appendage ligation may offer new strategies for preventing stroke.

The time required to get a device to market is critical to a successful design, development, and manufacturing process [1]. Achieving status of the first device to market is often a priority for manufacturers and developers. Upon market introduction, it is well known that device performance must meet at least minimum standards in order to provide consumer satisfaction and be a successful product to prevent competitive devices from taking over the market [1]. However, if a design only meets minimum expectations, it may struggle to maintain market control. This demonstrates the tradeoffs of speed-to-market and performance, for which optimization has not been clearly defined [2]. Product performance and usability can be designed in, evaluated and enhanced in order to avoid user errors and achieve optimal profitability. For medical devices, clinical trials are a key step in preparing to take a device to market. Clinical trials can allow for analyses of the effectiveness of the device in the patient care process. For wearable medical devices, patient usability is crucial to patient adherence and safety since the device will be operated by non-medically trained individuals [3,4]. Without adequate usability, adherence and continuity of care are greatly reduced which will reduce the overall effectiveness of the device [5,6]. Human factors principles can best be incorporated in the design process to improve the usability of medical devices and patient safety [5,6,7], specifically for those used in telemedicine [4] and cardiovascular treatment [3]. The objective of this project was to evaluate a telemedicine heart rate monitoring device for patient usability in order to improve the next device’s performance and lead to greater patient adherence for the current version via an improved user manual.

The primary disease target for our innovation is thromboembolic stroke from AF. This disease is addressed by removing the LAA from the systemic circulation using a novel percutaneous epicardial transcatheter based solution. In addition to avoiding the morbidity of open heart surgery, this solution does not necessitate entering a cardiac chamber. Thus, no device or hardware is exposed to the systemic circulation obviating the need for either procedural or even temporary postprocedural anticoagulation. Specific unique features of the innovation include a hollow suture, closure of the suture via a percutaneous approach, and the use of electrical signal-based navigation. Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice, and it poses a growing health hazard [1]. It affects 2.2 million Americans and is expected to afflict up to 16 million by the year 2050 [2]. Atrial fibrillation has been associated with an increased risk of thromboembolism [3]. Due to its complex anatomy and diminished blood flow during AF, the left atrial appendage (LAA) has been a common site of left atrial thrombi, accounting for 98% of such thrombi in transesophageal echocardiography (TEE)-based studies [4,5]. Currently, oral anticoagulation is the best established prophylactic therapy for stroke prevention in AF [6,7]. Unfortunately, due to numerous drug and dietary interactions, the narrow therapeutic window and need for frequent blood tests to ensure safe anticoagulation, as well as the inherent risk of major bleeding, warfarin is frequently underutilized in individuals at risk of thromboembolism [8,9]. Dabigatran, apixaban, and rivaroxaban are new oral agents that have been shown to be non-inferior or superior to warfarin in large

Epicardial cardiac resynchronization therapy (CRT) permits unrestricted electrode positioning. However, this requires surgical placement of device leads and the risk of unwanted phrenic nerve stimulation. We hypothesized that shielded electrodes can capture myocardium without extracardiac stimulation.In 6 dog and 5 swine experiments, we used a percutaneous approach to access the epicardial surface of the heart, and deploy novel leads housing multiple electrodes with selective insulation. Bipolar pacing thresholds at prespecified sites were tested compare electrode threshold data both facing towards and away from the epicardial surface.In 151 paired electrode recordings (70 in 6 dogs; 81 in 5 swine), thresholds facing myocardium were lower than facing away (median [IQR] mA: dogs 0.9 [0.4-1.6] vs 4.6 [2.1 to10], p0.0001; swine 0.5 [0.2-1] vs 2.5 [0.5-6.8], p0.0001). Myocardial capture was feasible without extracardiac stimulation at all tested sites, with mean ± SE threshold margin 3.6±0.7 mA at sites of high output extracardiac stimulation (p=0.004).Selective electrode insulation confers directional pacing to a multielectrode epicardial pacing lead. This device has the potential for a novel percutaneous epicardial resynchronization therapy that permits placement at an optimal pacing site, irrespective of the anatomy of the coronary veins or phrenic nerves.

Objective: Pharmacotherapy for epilepsy is limited with 30% of patients’ refractory to this approach of suppressing seizures. Current surgical options are invasive and carry significant morbidities including infection, bleeding, and the potential for deleterious neurocognitive effects. As a result, there is a burgeoning need for innovation to develop safer and efficacious interventions. Methods: Four distinct catheters (2 existing: Cardima catheter, Standard EPT Blazer catheter; 2 new prototypes: balloon catheter, basket catheters) were tested in 12 baboons (21-30 kg, 100% male). For each, we assessed whether or not the catheter was able to be maneuvered safely in various locations of the cerebral venous system, provide adequate cortical tissue contact to record signals, detect these signals as normal or abnormal, successfully stimulate the cortex, and capture the cortical tissue. Locations trialed included the petrosal sinus, straight sinus, vein of Galen, and occipital vein. Pacing cycle length and pacing thresholds varied among experiments. Results: Successful mapping was conducted in all 12 baboons. The pacing cycle length varied from 75 ms to 650 ms depending on location of the cortex. Pacing threshold was recorded in 4/12 (33%) of the experiments; data is not available for the remaining 8/12 experiments. The threshold values ranged from 0.3-20 mAmps. Capture of cortical electrical activity was observed in 11/12 (91.7%) experiments though the number of successful capture and stimulation attempts varied among experiments. The most reliable and consistent capture occurred with the use of our novel prototyped over-the-wire balloon catheter (9/12; 75%) and basket catheter (3/3; 100%). Necropsy and histology were performed post-experimentation, and only minimal complications were noted. Conclusion: New electrode design can be maneuvered safely in the venous system, provide adequate cortical tissue contact to record signals, detect these signals as normal or abnormal, successfully stimulate the cortex, and capture cortical tissue. These novel devices merit further study in chronic baboons to establish long-term efficacy of continuous seizure recording.

Echocardiographically detected patent foramen ovale (PFO) has been associated with stroke/transient ischemic attack (TIA) in patients with cardiac implantable electronic devices (CIEDs). We sought to evaluate the relationship between echocardiographic characteristics and risk of stroke/TIA and mortality in CIED patients with PFO.In 6,086 device patients, PFO was detected in 319 patients. A baseline echocardiogram was present in 250 patients, with 186 having a follow-up echocardiogram.Of 250 patients with a baseline echocardiogram, 9.6% (n = 24) had a stroke/TIA during mean follow-up of 5.3 ± 3.1 years; and 42% (n = 105) died over 7.1 ± 3.7 years. Atrial septal aneurysm, prominent Eustachian valve, visible shunting across PFO, baseline or change in estimated right ventricular systolic pressure (RVSP)/tricuspid regurgitation (TR), or maximum RVSP were not associated with postimplant stroke/TIA (P0.05). An exploratory multivariate analysis using time-dependent Cox models showed increased hazard of death in patients with increase in TR ≥2 grades (hazard ratio [HR] 1.780, 95% confidence interval [CI] 1.447-2.189, P0.0001), or increase in RVSP by10 mm Hg (HR 2.018, 95% CI 1.593-2.556, P0.0001), or maximum RVSP in follow-up (HR 1.432, 95% CI 1.351-1.516, P0.0001). A significant increase (P0.001) in TR was also noted during follow-up.In patients with CIED and PFO, structural and hemodynamic echocardiographic markers did not predict future stroke/TIA. However, a significantly higher TR or RVSP was associated with higher mortality.

The finding of a mobile calcific plaque attached to the aortic valve cusp during transcatheter aortic valve implantation (TAVI/TAVR) necessitated utilization of an embolic protection device, for cerebral protection. We report the urgent but successful deployment of such a filter in a patient with a single patent internal carotid artery. Although stroke rates observed in first-generation TAVI trials were higher than those reported following conventional open aortic valve replacement, adjunctive neuroprotective measures, particularly in patients with a large amount of threatened cerebral territory, may minimize potential neurologic injury.

Patients with cardiac tumours may present with cardiovascular related or constitutional symptoms, but more often than not a cardiac mass is discovered incidentally during an imaging examination performed for an unrelated indication. These incidental masses usually represent thrombi or vegetations, often occurring in a particular clinical milieu.1 If a mass is indeed a tumour, it is most likely malignant secondary to a known malignant process elsewhere, usually from the breast, lung or malignant melanoma. Much less likely, the mass represents a primary cardiac tumour. In this case it is most likely benign, with a nearly 50% likelihood of being a myxoma. Malignant primary cardiac tumours are exceedingly rare and represent only approximately a quarter of primary cardiac tumours. These are most often a variety of sarcoma. Although primary cardiac tumours are rare with an autopsy frequency of only 0.001–0.03%,2 they represent an important group of cardiovascular abnormalities because early and accurate diagnosis may be curative and sometimes avoids unnecessary surgery.1 3 Echocardiography is an ideal initial imaging modality since it is simple, non-invasive, widely available, and low cost. It delineates the morphologic appearance, location and motion of tumours as well as determining the haemodynamic consequences of the tumour, if any. CT and MRI are complimentary techniques that provide additional diagnostic information4 and are useful for staging and treatment planning, particularly when surgical resection is being considered. CT has better spatial resolution than MRI and also provides information about vascularity and calcification. MRI also provides information about vascularity, has better overall tissue characterisation, and does not have the attendant risk of radiation. Clinical symptoms and signs are often determined by location of the tumour rather than its histologic type. Thus, the clinical significance of a ‘benign’ tumour may be just as important as a ‘malignant’ type. Benign …

While for decades right ventricular (RV) apical pacing has been the standard of care for patients requiring pacemaker or defibrillator lead placement, investigators have sought alternatives to achieve more physiologic electrical activation of the heart and reduce long-term pathologic effects of nonphysiologic apical pacing. These investigations have included attempts at identifying superior pacing sites within the right atrium and RV and development of new leads to enhance specificity of sensing and capture. This review focuses on recent advances in alternative sites for pacing and developments in novel pacing technology ranging from intramyocardial electrodes to leadless pacemakers. First, there have been several studies demonstrating potential benefits of site-specific pacing, including His bundle pacing and RV outflow tract pacing in potentially attenuating electromechanical dyssynchrony and long-term functional decline seen with RV apical pacing. Available options for lead placement have been enhanced by development of intramyocardial electrodes that may significantly reduce far-field oversensing and nonchamber specific capture. With development of intramyocardial electrodes, the potential for atrioventricular septal pacing has recently been described, making synchronous activation of both ventricles with a one-lead system possible without crossing the tricuspid valve and offering an alternative to modern cardiac resynchronization therapy (CRT). Finally, recent advances in leadless pacemaker systems using ultrasound or magnetic fields are briefly discussed. The results of these studies suggest that there may be options to the RV apex, made possible by novel lead and pacemaker technology. These advances can potentially aid in reducing long-term negative effects of chronic pacemaker therapy.

Background While using echocardiography to guide endomyocardial biopsy (EMB), the authors have identified acute intracardiac thrombus formation related to the procedure, a hitherto unreported complication. The aims of this study were to identify the procedural details and characteristics of patients who developed this complication between June 2008 and April 2009 and to describe their outcomes and management. Methods In total, 415 right ventricular biopsies were performed during this period. Of these, 189 were echocardiographically guided, and the medical records of these patients were reviewed retrospectively. Results There were eight cases of acute right-sided intracardiac thrombus formation in seven patients (about 4% of the echocardiographically guided group) at the time of biopsy. The indications for EMB were heart transplant surveillance in six patients and suspected cardiac amyloidosis in one patient. Three cases were performed via a transjugular approach and four via a femoral approach. Four patients had histories of prior thromboses, and one patient had a defined clotting diathesis. Management included either immediate thrombus aspiration or postprocedural anticoagulation. There were no overt occurrences of pulmonary thromboembolism. Conclusions Acute thrombus formation is a complication of EMB. If this complication is unrecognized, and therefore untreated, pulmonary thromboembolism may result. This may have important clinical implications in patients undergoing routine repeated surveillance EMB after cardiac transplantation. The authors recommend performing transthoracic echocardiography during EMB, particularly in patients with histories of thrombosis, because this group of patients may be at increased risk for procedural thrombosis, and procedural echocardiography permits early recognition and treatment of this complication.

Background— Whether mechanical dyssynchrony indices predict reverse remodeling (RR) or clinical response to cardiac resynchronization therapy (CRT) remains controversial. This prospective study evaluated whether echocardiographic dyssynchrony indices predict RR or clinical response after CRT. Methods and Results— Of 184 patients with heart failure with anticipated CRT who were prospectively enrolled, 131 with wide QRS and left ventricular ejection fraction P =0.002). Overall, only M-mode, tissue Doppler strain, and total isovolumic time had a receiver operating characteristic area under the curve (AUC) greater than the line of no information, but none of these were strongly predictive of RR (AUC, 0.63 to 0.71). In nonischemic cardiomyopathy, no dyssynchrony index predicted RR. In ischemic cardiomyopathy, M-mode (AUC, 0.67), tissue Doppler strain (AUC, 0.79), and isovolumic time (AUC, 0.76) -derived indices predicted RR ( P Conclusions— These findings are consistent with the Predictors of Response to CRT study and do not support use of these dyssynchrony indices to guide use of CRT.

Objective To examine the hypothesis that speckle myocardial imaging (SMI) modalities, including longitudinal, radial and circumferential systolic (s) and diastolic (d) myocardial velocity imaging, displacement (D), strain rate (SR) and strain (S), as well as left ventricular (LV) rotation/torsion are sensitive for detecting early myocardial dysfunction in isolated LV non-compaction (iLVNC). Design and results Twenty patients with iLVNC diagnosed by cardiac magnetic resonance (15) or echocardiography (5) were included. Patients were divided into two groups: ejection fraction (EF)>50% (n=10) and EF≤50% (n=10). Standard measures of systolic and diastolic function including pulsed wave tissue Doppler Imaging (PWTDI) were obtained. Longitudinal, radial and circumferential SMI, and LV rotation/torsion were compared with values for 20 age/sex-matched controls. EF, PWTDI E9, E/E9 and all of the SMI modalities were significantly abnormal for patients with EF≤50% compared with controls. In contrast, EF and PWTDI E9, E/E9 were not significantly different between controls and patients with iLVNC (EF>50%). However, SMI-derived longitudinal sS, sSR, sD and radial sS, as well as LV rotation/torsion values, were all reduced in iLVNC (EF>50%) compared with controls. Measurements with the highest discriminating power between iLVNC (EF>50%) and controls were longitudinal sS mean of the six apical segments (area under the curve (AUC)=0.94), sS global average (AUC=0.94), LV rotation apical mean (AUC=0.94); LV torsion (AUC=0.93) LV torsion rate (AUC=0.94). Conclusions LV SMI values are reduced in patients with iLVNC, even those with normal EF and PWTDI. The most accurate SMI modalities to discriminate between patients and controls are longitudinal sS mean of the six apical segments, LV apical rotation or LV torsion rate.

Background: Right ventricular apical (RVA) pacing promotes tricuspid regurgitation (TR), electromechanical dyssynchrony, and ventricular dysfunction. We tested a novel intramyocardial bipolar lead to assess whether stimulation of the atrioventricular septum (AVS) produces synchronous ventricular activation without crossing the tricuspid valve (TV). Methods: A lead with an active external helix and central pin was placed on the AVS and the RVA in three dogs. High-density electroanatomic (EA) mapping was performed of both ventricles endocardially and epicardially. Intracardiac echocardiography was used to access ventricular synchrony. Results: The lead was successfully deployed into the AVS in all cases with consistent capture of the ventricular myocardium without atrial capture or sensing. The QRS duration was less with AVS compared with RVA pacing (89 ± 4 ms vs. 100 ± 11 ms [P < 0.0001, GEE P = 0.03]). There was decreased delay between color Doppler M-mode visualized peak contraction of the septum and the mid left ventricular free wall with AVS compared with RVA pacing (89 ± 91 ms vs. 250 ± 11 ms [P < 0.0001, GEE P = 0.006]). Activation time between the mid septum and mid free wall was shorter with AVS versus RVA pacing (20.4 ± 7.7 vs. 30.8 ± 11.6 [P = 0.01, GEE P = 0.07]). The interval between QRS onset to earliest free wall activation was shorter with AVS vs. RVA pacing (19.2 ± 6.4 ms vs. 31.1 ± 11.7 ms [P = 0.005, GEE P = 0.02]). Conclusion: The AVS was successfully paced in three dogs resulting in synchronous ventricular activation without crossing the TV.

Background: The use of oral calcium supplementation among the elderly for prevention and treatment of osteoporosis and osteopenia is increasing. The incidence of aortic valve disease and coronary artery disease also is increasing. No study thus far has been done to demonstrate whether this affects the progression of calcification in both the valves and vasculature. We sought to determine whether ingestion of oral calcium supplementation has an effect on aortic valve calcification (AVC) and coronary artery calcification (CAC). Methods: We performed an independent assessment of AVC, CAC, and calcium supplementation among patients enrolled in the Epidemiology of Coronary Artery Calcification study who were >60 years of age and had baseline and 4-year follow-up AVC data. In this population-based study of Olmsted County (Minnesota) residents, AVC and CAC scores were determined prospectively by electron beam computed tomography. We evaluated baseline demographic data and analyzed whether those patients using calcium supplementation had a higher rate of progression of both AVC and CAC. Results: We identified 257 patients (mean age, 67.8 ± 5.2 years), 144 of whom were women. Twenty-five patients (all women) reported using calcium supplements. Analysis of the 144 women (25 taking calcium supplementation) showed there was no difference in the progression of AVC (mean difference in baseline and follow-up AVC score; no supplement versus supplement, 30 ± 9 vs 39 ± 28; P = .73) or CAC (mean difference in baseline and follow-up CAC score; no supplement vs supplement, 47 ± 15 vs 112 ± 22; P = .154). There were no significant differences between the 2 groups with regard to baseline AVC, serum calcium, renal function, diabetes, hypertension, cholesterol, or body mass index. Conclusion: In this community-based observational study with a 4-year follow-up, no significant increased progression of AVC or CAC was found in women taking oral calcium supplementation. Larger prospective, randomized studies are needed to confirm these findings.

We aimed to determine whether smoking status affects the recurrence of atrial fibrillation or atrial flutter in patients after cardioversion. The clinical data of patients undergoing cardioversion for atrial flutter from January 1, 2000 to December 31, 2005 were prospectively collected. Arrhythmia recurrences were detected by retrospective review of comprehensive medical records and were determined using electrocardiography. The smoking history was prospectively collected through a standardized clinical form and subsequently categorized as lifetime nonsmoker, exsmoker, or current smoker. Univariate and multivariate associations with end points for clinical and lifestyle variables were assessed with Cox proportional hazards models. Women who were current smokers at cardioversion had a greater risk of atrial arrhythmia recurrence than did nonsmokers (hazard ratio 1.71, 95% confidence interval 1.10 to 2.67, p = 0.02). The increased risk of arrhythmia recurrence in female smokers was not seen in male smokers. Compared to lifetime nonsmokers, the mortality hazard ratio among men was 1.18 (95% confidence interval 0.88 to 1.58; p = 0.28) in exsmokers and 1.93 (95% confidence interval 1.20 to 3.11; p = 0.007) in current smokers. The risk of death after cardioversion was not increased in women. In conclusion, smoking is an independent predictor of atrial arrhythmia recurrence after cardioversion in women; however, an increased mortality risk, but not arrhythmia recurrence risk, was seen in men.

Direct-current cardioversion (DCCV) of atrial fibrillation and atrial flutter commonly causes post-DCCV left atrial (LA) stunning (LAS), which may potentiate thromboembolic complications. Data on LAS determinants are inconclusive.We prospectively evaluated LA and LA appendage function before and immediately after DCCV of atrial fibrillation and atrial flutter in 59 consecutive patients undergoing transesophageal echocardiographically guided DCCV to determine predictors of post-DCCV LAS.After exclusion of patients with pre-DCCV LAS (LA appendage emptying velocity20 cm/s), post-DCCV LAS was observed in 32 of 45 patients (71%). Only precardioversion mitral E-wave deceleration time significantly correlated with post-DCCV LAS (142 +/- 46 vs 170 +/- 360 milliseconds; P = .04). At 3.3 years, there was a trend toward a higher arrhythmia recurrence rate in patients with LAS compared with those without (86% vs 53%; P = .063).Only mitral E-wave deceleration time was predictive of post-DCCV LAS, which may be a marker of atrial fibrillation and atrial flutter recurrence.

Background— Various dyssynchrony indexes derived from tissue velocity and strain imaging have been proposed to predict the effectiveness of cardiac resynchronization therapy (CRT). We sought to compare the effect of CRT on dyssynchrony indexes derived by tissue velocity and strain and to determine which baseline intraventricular dyssynchrony parameters correlate with improvement in left ventricular volume after CRT. Methods and Results— Echocardiography with tissue Doppler imaging was performed in 45 patients with systolic heart failure at baseline, 1 day after CRT, and a median of 6 months after CRT. We calculated septal–lateral delay and anteroseptal–posterior delay and standard deviation of time to peak systolic velocity in the 12 basal and mid-left ventricular segments (Tv-SD). The standard deviation for time to peak strain in the 12 basal and mid-left ventricular segments (Tε-SD) was calculated as a strain-derived dyssynchrony index. None of the tissue velocity–derived dyssynchrony indexes improved after CRT (septal–lateral delay, P =0.39; anteroseptal–posterior delay, P =0.46; Tv-SD, P =0.30), whereas Tε-SD decreased significantly after CRT ( P r =0.66; P r =0.57; P Conclusions— The strain-derived dyssynchrony index is a better measurement than the tissue velocity dyssynchrony index for monitoring changes in mechanical dyssynchrony after CRT and for predicting reduction in left ventricular volume after CRT.

We reviewed our experience in managing intracardiac ultrasound-detected left atrial thrombus and analyzed the impact of the timing of heparin therapy on thrombus incidence.We identified 508 patients undergoing ablation procedures for atrial fibrillation in which intracardiac ultrasound was used. All patients received unfractionated heparin during the procedure: 31 patients before the first transseptal puncture (preTS1), 257 between the first and second transseptal punctures (TS1-TS2), and 220 following both punctures (postTS2). By using intracardiac echocardiography (ICE), thrombus was detected in 30 of these 508 patients (5.9%). Of these, 29 were in the left atrium and constituted our study group. In 21 patients, the thrombi were successfully aspirated from the left atrium using strong suction through the transseptal sheath. All patients in whom thrombi were aspirated did well without neurological event or death. When patients received heparin therapy either preTS1 or TS1-TS2, there was a significant decrease in the occurrence of ICE-detected left atrial thrombus compared with those who received heparin postTS2 (0 of 31 patients (0%) preTS, 9 of 257 (3.5%) TS1-TS2, and 20 of 220 (9.1%) postTS2; (preTS1 vs postTS2, p = 0.01; preTS2 [preTS1 and TS1-TS2] vs postTS2, p0.001).Early administration of intravenous heparin, specifically before transseptal puncture, decreases the incidence of left atrial thrombi.

Background— Several echocardiographic dyssynchrony indexes have been proposed to identify responders to cardiac resynchronization therapy using tissue velocity and strain. The present study aimed to compare tissue velocity–derived and strain-derived dyssynchrony indexes in patients with or without systolic dysfunction and left bundle-branch block. Methods and Results— Tissue Doppler imaging was performed in 120 subjects divided into 4 groups: group 1 (n=40), normal subjects; group 2 (n=20), normal left ventricular ejection fraction and left bundle-branch block; group 3 (n=20), left ventricular ejection fraction P =0.006), but there was a considerable overlap of all tissue velocity–derived indexes among 4 groups, with 40% to 68% of group 1 having values proposed for predicting the responders of cardiac resynchronization therapy. The SD of time to peak strain in 12 segments distinguished these groups with much less overlap ( P Conclusions— A substantial proportion of normal subjects have tissue velocity–derived dyssynchrony indexes higher than the cutoff value proposed for predicting beneficial effect of cardiac resynchronization therapy. Strain-derived timing index appears to be more specific for dyssynchrony in patients with systolic dysfunction and left bundle-branch block. Identifying an optimal tissue velocity– or strain-derived dyssynchrony index requires a large prospective clinical trial.

The purpose of this study was to determine whether a non-sonographer clinician (NSC) could obtain ultrasound images of the carotid artery, measure carotid intima-media thickness (CIMT), and identify findings indicating increased cardiovascular risk in an office setting.Eight NSCs from five sites were trained to use a handheld ultrasound device to screen the carotid arteries for plaques and to measure CIMT.NSCs scanned 150 subjects who provided 900 images, of which 873 (97%) were interpretable. Differences between NSCs and the core laboratory were small (0.002 +/- 0.004 mm) and bioequivalent (P(TOST)0.05) with a low coefficient of variation (3.9% +/- 0.5%). There wasor = 90% agreement on the presence of CIMTor = 75th percentile andor = 80% agreement on plaque presence.This is the first multicenter study to show that NSCs can obtain images of the carotid arteries using a handheld ultrasound device, accurately measure CIMT, and identify findings indicating increased cardiovascular risk.

Automated external defibrillators can provide life-saving therapies to treat ventricular fibrillation. We developed a prototype unit that can deliver a unique shock waveform produced by four independent capacitors that is delivered through two shock vectors, with the rationale of providing more robust shock pathways during emergent defibrillation. We describe the initial testing and feasibility of this unique defibrillation unit, features of which may enable downsizing of current defibrillator devices.We tested our defibrillation unit in four large animal models (two canine and two swine) under general anesthesia. Experimental defibrillation thresholds (DFT) were obtained by delivery of a unique waveform shock pulse via a dual-vector pathway with four defibrillation pads (placed across the chest). DFTs were measured and compared with those of a commercially available biphasic defibrillator (Zoll M series, Zoll Medical, Chelmsford, MA, USA) tested in two different vectors. Shocks were delivered after 10 seconds of stable ventricular fibrillation and the output characteristics and shock outcome recorded. Each defibrillation series used a step-down to failure protocol to define the defibrillation threshold.A total of 96 shocks were delivered during ventricular fibrillation in four large animals. In comparison to the Zoll M series, which delivered a single-vector, biphasic shock, the energy required for successful defibrillation using the unique dual-vector biphasic waveform did not differ significantly (P = 0.65).Our early findings support the feasibility of a unique external defibrillation unit using a dual-vector biphasic waveform approach. This warrants further study to leverage this unique concept and work toward a miniaturized, portable shock delivery system.

Background Hyper‐ and hypokalemia are clinically silent, common in patients with renal or cardiac disease, and are life threatening. A noninvasive, unobtrusive, blood‐free method for tracking potassium would be an important clinical advance. Methods and Results Two groups of hemodialysis patients (development group, n=26; validation group, n=19) underwent high‐resolution digital ECG recordings and had 2 to 3 blood tests during dialysis. Using advanced signal processing, we developed a personalized regression model for each patient to noninvasively calculate potassium values during the second and third dialysis sessions using only the processed single‐channel ECG . In addition, by analyzing the entire development group's first‐visit data, we created a global model for all patients that was validated against subsequent sessions in the development group and in a separate validation group. This global model sought to predict potassium, based on the T wave characteristics, with no blood tests required. For the personalized model, we successfully calculated potassium values with an absolute error of 0.36±0.34 mmol/L (or 10% of the measured blood potassium). For the global model, potassium prediction was also accurate, with an absolute error of 0.44±0.47 mmol/L for the training group (or 11% of the measured blood potassium) and 0.5±0.42 for the validation set (or 12% of the measured blood potassium). Conclusions The signal‐processed ECG derived from a single lead can be used to calculate potassium values with clinically meaningful resolution using a strategy that requires no blood tests. This enables a cost‐effective, noninvasive, unobtrusive strategy for potassium assessment that can be used during remote monitoring.