Correlation of ventricular pacing burden and left ventricular function in patients with heart failure with reduced ejection fraction.

BACKGROUND: Pacemaker-induced cardiomyopathy is a well described phenomenon in patients with preserved ejection fraction at the time of permanent pacemaker implant. One of the identified risk factors for pacemaker-induced cardiomyopathy is the degree of ventricular pacing burden. However, it is unclear how a high right ventricular pacing burden affects patients with depressed left ventricular function at the time of pacemaker implantation. We sought to assess the relationship between right ventricular pacing and change in left ventricular function over time. METHODS: We conducted an analysis of all patients who had received either a single or dual lead cardiac implantable electronic devices, excluding biventricular devices, and had a prior transthoracic echocardiogram demonstrating an ejection fraction of less than 50%. The primary end-point was the correlation between the percentage of ventricular pacing and the change in LV ejection fraction. RESULTS: Fifty eight patients with preceding heart failure had pacemakers implanted and had follow up echocardiograms. There was no correlation between the degree of ventricular pacing and the absolute change in LV function (r = .04, p = .979). None of the previously identified risk factors for pacemaker induced cardiomyopathy were predictive of a significant fall in ejection fraction. CONCLUSION: The degree of RV pacing and other established risk factors for pacemaker-induced cardiomyopathy in patients with normal left ventricular function at the time of implantation do not appear to carry the same risk in patients with pre-existing heart failure who receive either single or dual lead pacemakers.

Efficacy of intravenous magnesium for the management of non-post operative atrial fibrillation with rapid ventricular response: A systematic review and meta-analysis.

BACKGROUND: Intravenous magnesium (IV Mg), a commonly utilized therapeutic agent in the management of atrial fibrillation (AF) with rapid ventricular response, is thought to exert its influence via its effect on cellular automaticity and prolongation of atrial and atrioventricular nodal refractoriness thus reducing ventricular rate. We sought to undertake a systematic review and meta-analysis of the effectiveness of IV Mg versus placebo in addition to standard pharmacotherapy in the rate and rhythm control of AF in the nonpostoperative patient cohort given that randomized control trials (RCTs) have shown conflicting results. METHODS: Randomized controlled trials comparing IV Mg versus placebo in addition to standard of care were identified via electronic database searches. Nine RCTs were returned with a total of 1048 patients. Primary efficacy endpoints were study-defined rate control and rhythm control/reversion to sinus rhythm. The secondary endpoint was patient experienced side effects. RESULTS: Our analysis found IV Mg in addition to standard care was successful in achieving rate control (odd ratio [OR] 1.87, 95% confidence interval [CI] 1.13-3.11, p = .02) and rhythm control (OR 1.45, 95% CI 1.04-2.03, p = .03). Although not well reported among studies, there was no significant difference between groups regarding the likelihood of experiencing side effects. CONCLUSIONS: IV Mg, in addition to standard-of-care pharmacotherapy, increases the rates of successful rate and rhythm control in nonpostoperative patients with AF with rapid ventricular response and is well tolerated.

Diabetes mellitus is an independent predictor of obstructive coronary artery disease in patients presenting with atrial fibrillation and elevated troponin.

Atrial fibrillation can present with symptoms of myocardial infarction and elevated troponin, even in the absence of obstructive coronary artery disease (CAD). We sought to determine the characteristics that predict underlying obstructive CAD. Obstructive CAD was far more likely in those with troponin elevation. In those with elevated troponin, diabetes mellitus was an independent predictor of obstructive CAD.

Outcomes of thrombus aspiration during primary percutaneous coronary intervention for ST-elevation myocardial infarction.

BACKGROUND: Previous large multi-centre randomised controlled trials have not provided clear benefit with routine intracoronary thrombus aspiration (TA) as an adjunct to primary percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI). AIM: To determine whether there is a difference in outcomes with the use of manual TA prior to PCI, compared with PCI alone in a cohort of patients with STEMI. METHODS: We analysed data from 6270 consecutive patients undergoing primary PCI for STEMI prospectively enrolled in the Melbourne Interventional Group registry between 2007 and 2018. Multivariable analysis was performed to determine predictors of 30-day major adverse cardiovascular and cerebrovascular events (MACCE) and long-term mortality. RESULTS: We compared 1621 (26%) patients undergoing primary PCI with TA to 4649 (74%) patients undergoing PCI alone. Male gender (81% vs 78%; P < 0.01), younger age (61 vs 63 years; P = 0.03), GP-IIb/IIIa use (76% vs 58%, P < 0.01), and current smoking (40% vs 36%; P < 0.01) were more common in the TA group. TA was more likely to be used in patients with complex lesions (83% vs 66%; P < 0.01) with TIMI 0 flow (77% vs 56%; P < 0.01). No significant difference in post-procedural TIMI flow, stroke, 30-day mortality, or long-term mortality were identified. Multivariable analysis demonstrated a reduction in 30-day MACCE (hazard ratio (HR) 0.75; confidence interval (CI) 0.63-0.89; P < 0.01) in the TA group, but was not associated with long-term mortality (HR 0.98; CI 0.85-1.1; P = 0.73). CONCLUSION: The use of TA in patients undergoing primary PCI for STEMI was not associated with improved short or long-term mortality when compared with PCI alone.

Vibrational and acoustic communication in fishes: The overlooked overlap between the underwater vibroscape and soundscape.

Substrate-borne communication via mechanical waves is widespread throughout the animal kingdom but has not been intensively studied in fishes. Families such as the salmonids and sculpins have been documented to produce vibratory signals. However, it is likely that fish taxa on or close to the substrate that produce acoustic signals will also have a vibratory component to their signal due to their proximity to substrates and energy transfer between media. Fishes present an intriguing opportunity to study vibrational communication, particularly in the context of signal production and detection, detection range, and how vibratory signals may complement or replace acoustic signals. It is highly likely that the vibrational landscape, the vibroscape, is an important component of their sensory world, which certainly includes and overlaps with the soundscape. With the wide range of anthropogenic activities modifying underwater substrates, vibrational noise presents similar risks as acoustic noise pollution for fishes that depend on vibrational communication. However, in order to understand vibrational noise, more empirical studies are required to investigate the role of vibrations in the fish environment.

Marine energy converters: Potential acoustic effects on fishes and aquatic invertebrates.

The potential effects of underwater anthropogenic sound and substrate vibration from offshore renewable energy development on the behavior, fitness, and health of aquatic animals is a continuing concern with increased deployments and installation of these devices. Initial focus of related studies concerned offshore wind. However, over the past decade, marine energy devices, such as a tidal turbines and wave energy converters, have begun to emerge as additional, scalable renewable energy sources. Because marine energy converters (MECs) are not as well-known as other anthropogenic sources of potential disturbance, their general function and what is known about the sounds and substrate vibrations that they produce are introduced. While most previous studies focused on MECs and marine mammals, this paper considers the potential of MECs to cause acoustic disturbances affecting nearshore and tidal fishes and invertebrates. In particular, the focus is on particle motion and substrate vibration from MECs because these effects are the most likely to be detected by these animals. Finally, an analysis of major data gaps in understanding the acoustics of MECs and their potential impacts on fishes and aquatic invertebrates and recommendations for research needed over the next several years to improve understanding of these potential impacts are provided.

Families' experiences of supporting Australian veterans to seek help for a mental health problem: a linked data analysis of national surveys with families and veterans.

BACKGROUND: Families play a critical role in supporting currently serving and transitioned veterans' wellbeing and help-seeking for mental health concerns; however, little is known about families' experiences. AIMS: This study used Australian national survey linked-data (n = 1217) from families (Family Wellbeing Study-FWS) and veterans (Mental Health Wellbeing Transition Study-MHWTS) to understand veteran-family help-seeking relationships. METHODS: Veterans' and family members' responses to mental health and help-seeking questions in FWS and MHWTS datasets from perspective of family members were cross-tabulated. Help-seeking support provided by family members was compared by veterans' probable disorder. RESULTS: Results highlighted high levels of involvement and continuous assistance provided by families. Two in three family members thought the veteran had probable mental health concerns although they have never been diagnosed or treated. Clear disparities between family and veteran perspectives regarding mental health concerns indicates the extent of non-treatment seeking in this population, missed opportunities for early intervention, and need for greater support to families to promote help-seeking. CONCLUSIONS: Encouraging help-seeking is complex for veteran families particularly where veterans' reluctance to seek help may lead to family relationship strain and conflict. Families need early information, support, and recognition by service agencies of the role of the family in encouraging help-seeking.

Diabetes mellitus is independently associated with early stent thrombosis in patients undergoing drug eluting stent implantation: Analysis from the Victorian cardiac outcomes registry.

BACKGROUND: Diabetes mellitus (DM) is a predictor of restenosis and late stent thrombosis (ST) in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting-stents (DES). Real-world data on rates of early ST is lacking. We compared clinical outcomes of patients with and without DM from the Victorian cardiac outcomes registry. METHODS: Consecutive patients undergoing PCI with DES were analyzed with primary outcome being ST at 30-days. Secondary outcomes including major adverse cardiovascular events (MACE) and all-cause mortality. RESULTS: Of 43,209 patients included, 9730 (22.5%) had DM. At 30 days, DM was independently associated with higher rates of early ST (0.7% vs. 0.5%) OR 1.41 (95% confidence interval; 1.05-1.87, p = 0.02), MACE (4.1% vs. 3.5%, p = 0.004) and mortality (1.9% vs. 1.5%, p = 0.01). Increased risk was not simply due to treatment. Patients with DM requiring insulin were equally affected in regard to MACE (4.7% vs. 3.9%, p = 0.069) and mortality (1.9%, vs. 1.8%, p = 0.746). On National Death Index linkage, patients with DM had increased all-cause mortality over five-year follow-up (OR 1.69 CI 1.55-1.83, p = < 0.001). CONCLUSION: In this large real-world-registry, DM was an independent predictor of early ST, MACE and mortality at 30 days. These data suggest additional therapeutic strategies are required to reduce the risk of early complications in patients with DM undergoing PCI with DES.

Offshore wind energy development: Research priorities for sound and vibration effects on fishes and aquatic invertebrates.

There are substantial knowledge gaps regarding both the bioacoustics and the responses of animals to sounds associated with pre-construction, construction, and operations of offshore wind (OSW) energy development. A workgroup of the 2020 State of the Science Workshop on Wildlife and Offshore Wind Energy identified studies for the next five years to help stakeholders better understand potential cumulative biological impacts of sound and vibration to fishes and aquatic invertebrates as the OSW industry develops. The workgroup identified seven short-term priorities that include a mix of primary research and coordination efforts. Key research needs include the examination of animal displacement and other behavioral responses to sound, as well as hearing sensitivity studies related to particle motion, substrate vibration, and sound pressure. Other needs include: identification of priority taxa on which to focus research; standardization of methods; development of a long-term highly instrumented field site; and examination of sound mitigation options for fishes and aquatic invertebrates. Effective assessment of potential cumulative impacts of sound and vibration on fishes and aquatic invertebrates is currently precluded by these and other knowledge gaps. However, filling critical gaps in knowledge will improve our understanding of possible sound-related impacts of OSW energy development to populations and ecosystems.

Angiotensin-Converting Enzyme 2 Activity Is Associated With Embolic Stroke of Undetermined Source.

[Figure: see text].

Substrate-borne vibration and sound production by the land hermit crab Coenobita compressus during social interactions.

Despite the diversity of sound production in crustacea, sounds produced by the land hermit crabs (Coenobitidae) are not well understood. Here, sound and substrate-borne vibration production by the tropical species Coenobita compressus was characterized in relation to shell architecture and social context. Sound production rates were compared between group and solitary conditions. Chirps were measurable in the air (peak frequency 800-8400 Hz) and within the sediment (40-1120 Hz). On average, chirp pulses were 0.08 s, spaced 0.41-0.92 s apart, and had trains composed of 4-6 pulses. There were significant correlations between the shell architecture and chirp vibroacoustics. Notably, a correlation between the substrate-borne peak frequency and shell wall thickness was found, indicating that the shell remodeling process which crabs undertake (shell wall thinning) impacts the vibroacoustics of the chirps. Chirp production was significantly linked to sociality during increased individual proximity and shell contests; hence, the function is hypothesized to be intraspecific communication relative to personal space and defense. Although there have been anecdotal observations of chirping in the Coenobitidae, this paper provides a full characterization of C. compressus, which produces chirps in two sensory modes, indicating the potential of being a seismic signaler.

Re-starting elective orthopaedic services in NHS Tayside during the COVID-19 pandemic.

BACKGROUND: Elective orthopaedic operations were suspended at the start of the COVID-19 lockdown. Three pathways were created to allow patients to undergo urgent elective operations in NHS Tayside as soon as it was deemed safe to do so. METHODS: We examined elective orthopaedic activity in NHS Tayside during and immediately after the Scottish lockdown. Elective operations performed between 27 March 2020 and 10 August 2020 were included and compared with cases performed between 27 March and 10 August in both 2018 and 2019. Primary outcomes were 30-day mortality, 30-day complications, and nosocomial infection rates of COVID-19. FINDINGS: Fewer elective operations were performed in 2020 (258) compared with 2019 (1196) and 2018 (1261). The rate of nosocomial infection in the 2020 cohort was 0%. The 30-day mortality rate was 0%. Over 98% of patients agreed to undergo surgery after a detailed consenting process. INTERPRETATION: We were able to re-start a safe elective orthopaedic service in the early stages of recovery from the COVID-19 pandemic, compatible with the guidelines set by the Royal College of Surgery of England and the British Orthopaedic Association. Our findings will serve to reassure regions with sufficient resources that it is acceptable to restart elective surgery for urgent priority cases. They may provide a template for planned surgical care in the event of further pandemics.

Corporate parenting in a pandemic: Considering the delivery and receipt of support to care leavers in Wales during Covid-19.

This paper considers the support available to care leavers during the Covid-19 pandemic from their corporate parents. The paper contributes to a developing evidence base concerned with social work efforts to adapt and maintain support provision during the unprecedented circumstances, and provides insight into how such support was perceived and experienced. Funded by Voices from Care Cymru and Cardiff University, a qualitative, mixed method study was conducted which included a survey of Welsh Local Authority professionals (n = 22) and interviews with Welsh care-experienced young people aged 17-24 (n = 17). The findings of this paper show the propensity of corporate parents to provide protection against the adversities of the pandemic, or to compound difficulties. While some young people reported being both practically and emotionally supported, for others corporate parenting support was perceived as unavailable, unhelpful and / or uncaring. The Covid-19 pandemic provides a unique lens to consider the strengths, flaws and future opportunities for corporate parenting. The findings emphasise the need for parity of support for young people leaving care and consideration of national, local and individual responses is included. Yet consistent with findings pre-dating the pandemic, the findings reaffirm the enduring importance of both relationships and resources in ensuring good support for care leavers.

The effects of emergency medical service work on the psychological, physical, and social well-being of ambulance personnel: a systematic review of qualitative research.

BACKGROUND: High rates of mental distress, mental illness, and the associated physical effects of psychological injury experienced by ambulance personnel has been widely reported in quantitative research. However, there is limited understanding of how the nature of ambulance work contributes to this problem, the significant large toll that emergency medical response takes on the individual, and particularly about late and cumulative development of work-related distress among this first responder workforce. METHODS: This study examined peer-reviewed qualitative research published from 2000 to 2018 to outline the effect of emergency medical response work on the psychological, psychosocial, and physical health of paramedics, ambulance officers, ambulance volunteers, and call-takers. Databases searched included: Ovid Medline, CINAHL, Ovid EMcare, PsychInfo and Scopus. The systematic review was organised around five key areas: impact of the work on psychological wellbeing; impact of psychological stress on physical wellbeing; how work-related well-being needs were articulated; effects of workflow and the nature of the work on well-being; and, effects of organisational structures on psychological and physical well-being. RESULTS: Thirty-nine articles met the eligibility criteria. Several factors present in the day-to-day work of ambulance personnel, and in how organisational management acknowledge and respond, were identified as being significant and contributing to mental health and well-being, or increasing the risk for developing conditions such as PTSD, depression, and anxiety. Ambulance personnel articulated their well-being needs across four key areas: organisational support; informal support; use of humour; and individual mechanisms to cope such as detachment and external supports. CONCLUSIONS: Interactions between critical incidents and workplace culture and demands have an overwhelming impact on the psychological, physical and social well-being of ambulance personnel. These include day-to-day managerial actions and responses, the impact of shift work, poorly-managed rosters, and long hours of work with little time between for recovery. Mental health issues result from exposure to traumatic events, and the way managers and peers respond to worker distress. Ambulance personnel suffering from work-related stress feel abandoned by peers, management, and the service, during illness, in return-to-work, and post-retirement. Policy, programmes and interventions, and education need to occur at an individual, peer, organisational, and government level.

Atezolizumab with or without cobimetinib versus regorafenib in previously treated metastatic colorectal cancer (IMblaze370): a multicentre, open-label, phase 3, randomised, controlled trial.

BACKGROUND: Microsatellite-stable metastatic colorectal cancer is typically unresponsive to immunotherapy. This phase 3 study was designed to assess atezolizumab plus cobimetinib in metastatic colorectal cancer. Here, we report the comparison of atezolizumab plus cobimetinib or atezolizumab monotherapy versus regorafenib in the third-line setting. METHODS: IMblaze 370 is a multicentre, open-label, phase 3, randomised, controlled trial, done at 73 academic medical centres and community oncology practices in 11 countries. Patients aged at least 18 years with unresectable locally advanced or metastatic colorectal cancer, baseline Eastern Cooperative Oncology Group performance status of 0-1, and disease progression on or intolerance to at least two previous systemic chemotherapy regimens were enrolled. We used permuted-block randomisation (block size four) to assign patients (2:1:1) via an interactive voice and web response system to atezolizumab (840 mg intravenously every 2 weeks) plus cobimetinib (60 mg orally once daily for days 1-21 of a 28-day cycle), atezolizumab monotherapy (1200 mg intravenously every 3 weeks), or regorafenib (160 mg orally once daily for days 1-21 of a 28-day cycle). Stratification factors were extended RAS status (wild-type vs mutant) and time since diagnosis of first metastasis (<18 months vs ≥18 months). Recruitment of patients with high microsatellite instability was capped at 5%. The primary endpoint was overall survival in the intention-to-treat population. Safety was assessed in the population of patients who received at least one dose of their assigned treatment. IMblaze370 is ongoing and is registered with ClinicalTrials.gov, number NCT02788279. FINDINGS: Between July 27, 2016, and Jan 19, 2017, 363 patients were enrolled (183 patients in the atezolizumab plus cobimetinib group, 90 in the atezolizumab group, and 90 in the regorafenib group). At data cutoff (March 9, 2018), median follow-up was 7·3 months (IQR 3·7-13·6). Median overall survival was 8·87 months (95% CI 7·00-10·61) with atezolizumab plus cobimetinib, 7·10 months (6·05-10·05) with atezolizumab, and 8·51 months (6·41-10·71) with regorafenib; the hazard ratio was 1·00 (95% CI 0·73-1·38; p=0·99) for the combination versus regorafenib and 1·19 (0·83-1·71; p=0·34) for atezolizumab versus regorafenib. Grade 3-4 adverse events were reported in 109 (61%) of 179 patients in the atezolizumab plus cobimetinib group, 28 (31%) of 90 in the atezolizumab group, and 46 (58%) of 80 in the regorafenib group. The most common all-cause grade 3-4 adverse events in the combination group were diarrhoea (20 [11%] of 179), anaemia (ten [6%]), increased blood creatine phosphokinase (12 [7%]), and fatigue (eight [4%]). Serious adverse events were reported in 71 (40%) of 179 patients in the combination group, 15 (17%) of 90 in the atezolizumab group, and 18 (23%) of 80 in the regorafenib group. Two treatment-related deaths occurred in the combination group (sepsis) and one in the regorafenib group (intestinal perforation). INTERPRETATION: IMblaze370 did not meet its primary endpoint of improved overall survival with atezolizumab plus cobimetinib or atezolizumab versus regorafenib. The safety of atezolizumab plus cobimetinib was consistent with those of the individual drugs. These results underscore the challenge of expanding the benefit of immunotherapy to patients whose tumours have lower baseline levels of immune inflammation, such as those with microsatellite-stable metastatic colorectal cancer. FUNDING: F Hoffmann-La Roche Ltd/Genentech Inc.

Outcomes in patients with peripheral vascular disease following percutaneous coronary intervention.

OBJECTIVES: To evaluate the clinical characteristics and outcomes of patients with peripheral vascular disease (PVD) undergoing percutaneous coronary intervention (PCI) in a contemporary setting, and to determine whether use of drug-eluting stents (DESs) improves outcomes. BACKGROUND: PVD was an independent risk factor for adverse outcomes following PCI in the bare-metal stent (BMS) era. It is not known whether outcomes in these patients have improved with advances in interventional techniques and stent technology, as they have for the general population. METHODS: Eighteen thousand three hundred and eighty patients undergoing PCI from an Australian registry between 2005 and 2013 were studied. Clinical and procedural data, 30-day and 12-month outcomes were compared in those with and without a reported history of PVD. Outcomes were also compared between patients with PVD who received DES and those who received BMS. Long-term mortality was compared using Australian National Death Index (NDI) linkage. RESULTS: Patients with PVD (n = 1,251, 6.8%) were older and had more prevalent diabetes, hypertension, cerebrovascular disease, heart failure, renal impairment, ostial lesions, left main, and multi-vessel disease (p < 0.001). Patients with PVD had significantly higher rates of major adverse cardiovascular events (MACEs) compared with those without PVD, in-hospital (5.7% vs. 4.1%, p < 0.008), at 30-days (8.6% vs. 5.8%, p < 0.001) and at 12-months (24.6% vs. 13.2%, p < 0.001). At 4.9 ± 2.6 years follow-up, there was significantly greater mortality in the PVD group. PVD patients who received DES experienced significantly less MACE than PVD patients treated with BMS at 30-days (4.8 vs. 10.1%, p < 0.001) and 12-months (19.4 vs. 26.4%, p < 0.005). CONCLUSIONS: PVD is an independent predictor of adverse outcomes in patients undergoing PCI. PVD patient who received DES had improved outcomes compared with those receiving BMS.

Get off my back: vibrational assessment of homeowner strength.

Animals may use a variety of sensory modalities to assess ownership and resource-holding potential (RHP). However, few studies have experimentally tested whether animals can assess these key variables through a purely vibrational modality, exclusively involving substrate-borne vibrations. Here we studied social terrestrial hermit crabs ( Coenobita compressus), where competitors assess homeowners by climbing on top of a solid external structure-an architecturally remodelled shell home, inside of which the owner then produces vibrations. In the field, we used a miniature vibratory device, hidden within an empty shell, to experimentally simulate a 'phantom owner', with variable amplitudes of vibration representing different levels of homeowner strength. We found that assessors could use these vibrations to deduce the owner's RHP: for strong vibrations (indicative of a high RHP owner) assessors were least likely to escalate the conflict; for weak vibrations (indicative of a low RHP owner) assessors showed intermediate escalation; and in the absence of vibration (indicative of an extremely weak or absent owner) assessors were most likely to escalate. These results reveal that animals can assess homeowner strength based solely on substrate vibrations, thereby making important decisions about whether to escalate social conflicts over property.

"I was worried if I don't have a broken leg they might not take it seriously": Experiences of men accessing ambulance services for mental health and/or alcohol and other drug problems.

BACKGROUND: A large proportion of ambulance callouts are for men with mental health and/or alcohol and other drug (AOD) problems, but little is known about their experiences of care. This study aimed to describe men's experiences of ambulance care for mental health and/or AOD problems, and factors that influence their care. METHODS: Interviews were undertaken with 30 men who used an ambulance service for mental health and/or AOD problems in Australia. Interviews were analysed using the Framework approach to thematic analysis. RESULTS: Three interconnected themes were abstracted from the data: (a) professionalism and compassion, (b) communication and (c) handover to emergency department staff. Positive experiences often involved paramedics communicating effectively and conveying compassion throughout the episode of care. Conversely, negative experiences often involved a perceived lack of professionalism, and poor communication, especially at handover to emergency department staff. CONCLUSION: Increased training and organizational measures may be needed to enhance paramedics' communication when providing care to men with mental health and/or AOD problems.

Poor reliability of P-wave terminal force V1 in ischemic stroke.

INTRODUCTION: Several ECG markers are postulated to represent underlying atrial remodelling and have been associated with ischemic stroke. P-wave terminal force in lead V1 (PTFV1) is one such marker. We examined the factors that contribute to the reliability of PTFV1 and its association with ischemic stroke. MATERIAL AND METHODS: Four hundred and thirty-five patients that presented with an ischemic stroke or transient ischemic attack (TIA) were identified through a prospectively maintained multi-site institutional stroke database. Control group consisted of age matched patients without prior history of an ischemic stroke or TIA. All patients underwent a 12-lead ECG and 24-hour Holter monitoring during the study period to exclude atrial fibrillation. RESULTS: Morphology consistent with PTFV1 occurred commonly in both the stroke/TIA and control groups. There was no significant difference in the median PTFV1 value between the stroke 3.96 mV ms [Interquartile range (IQR) 2.78-5.58] and control 4.23 mV ms [IQR 2.91-5.57] groups. Measurements of PTFV1 demonstrated excellent intra-observer reliability on assessment of the same P-wave (Intra class correlation (ICC) 0.91, p < 0.001) with narrow limits of agreement 2.21 to -2.95 mV ms. A change in the P wave assessed led to a significant reduction in reliability (ICC 0.79, p < 0.001). Inter-observer, inter P-wave assessment demonstrated further reduction in reliability (ICC 0.68, p < 0.002) with wide limits of agreement 6.17 to -5.78 mV ms, indicating significant under and overestimation of PTFV1. CONCLUSION: The utility of PTFV1 as a clinical marker for ischemic stroke is limited by the reduction in reliability associated with inter-observer and inter P-wave measurements.

Accuracy of blinded clinician interpretation of single-lead smartphone electrocardiograms and a proposed clinical workflow.

Despite the appeal of smartphone-based electrocardiograms (ECGs) for arrhythmia screening, a paucity of data exists on the accuracy of primary care physicians' and cardiologists' interpretation of tracings compared with the device's automated diagnosis. Using 408 ECGs in 51 patients, we demonstrate a variable accuracy in clinician interpretation of smartphone-based ECGs, with only cardiologists demonstrating satisfactory agreement when referenced against a 12-lead ECG. Combining the device automated diagnostic algorithm with cardiologist interpretation of only uninterpretable traces yielded excellent results and provides an efficient, cost-effective workflow for the utilization of a smartphone-based ECG in clinical practice.