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BACKGROUND Sudden cardiac death (SCD) during physical exercise is devastating. We aimed to evaluate causes and circumstances of exercise-related SCD in the young in Australia. METHODS We reviewed the National Coronial Information System database for deaths in Australia relating to cardiovascular disease in cases aged 10-35 years between 2000-2016. Included cases had undertaken physical exercise at time of event. We collected demographics, circumstances of death, type of physical exercise, bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use prior to ambulance arrival. RESULTS Over a 17-year period, 1,925 SCD cases were identified of which 110 cases (6%) (median age 27 years [interquartile range [IQR] 21-32 years], 92% male) were related to sports/physical exercise. Thirteen cases (12%) occurred in active athletes. Most common causes were coronary artery disease (CAD; 37%) and sudden arrhythmic death syndrome (SADS; 20%). Amongst Aboriginal and Torres Strait Islanders (n=10), all deaths were related to CAD. Australian Rules Football (24%), running/jogging (14%) and soccer (14%) were the most frequent physical exercise activities. Prior symptoms were present in 39% (chest pain 37%, presyncope/syncope 26%). Most were witnessed (87%) with bystander CPR in 70%. AED use prior to ambulance arrival was 8%. CONCLUSIONS This study demonstrates the high occurrence of CAD and SADS in SCD in the young related to physical exercise. Aboriginal and Torres Strait Islanders were disproportionately affected by CAD. Although events were commonly witnessed, AED was seldom used prior to ambulance arrival and highlights an important opportunity to improve outcomes in the post-arrest chain of survival. This article is protected by copyright. All rights reserved.

[Extract] We recruited every player from a squad of professional basketballers involved in a ‘super-spreader’ event that lead to a majority being infected with COVID-19 following a single training session in Melbourne, Australia. We compared those athletes who tested positive to COVID-19 by polymerase chain reaction diagnostic testing (16 athletes) to athletes who (i) tested negative and (ii) had no symptoms suggestive of COVID-19 infection (n = 8).

We propose that for correct clinical interpretation of exaggerated exercise blood pressure (EEBP), both cardiorespiratory fitness and exercise workload must be considered. A key recommendation towards achieving the correct clinical interpretation of EEBP is that exercise BP should be measured during submaximal exercise with a fixed external workload.

Atrial enlargement in response to pathological stimuli (e.g., hypertension, mitral valve disease) and physiological stimuli (exercise, pregnancy) can be comparable in magnitude, but the diseased enlarged atria is associated with complications such as atrial fibrillation (AF), whereas physiological atrial enlargement is not. Pathological atrial enlargement and AF is also observed in a small percentage of athletes undergoing extreme/intense endurance sport and pregnant women with preeclampsia. Differences between physiological and pathological atrial enlargement and underlying mechanisms are poorly understood. This review describes human and animal studies characterizing atrial enlargement under physiological and pathological conditions and highlights key knowledge gaps and clinical challenges, including: 1) the limited ability of atria to reverse remodel; and 2) distinguishing physiological and pathological enlargement via imaging/biomarkers. Finally, this review discusses how targeting distinct molecular mechanisms underlying physiological and pathological atrial enlargement could provide new therapeutic and diagnostic strategies for preventing or reversing atrial enlargement and AF.

Exercise oscillatory ventilation (EOV) is a form of periodic breathing that is associated with a poor prognosis in heart failure patients, but little is known about EOV in other populations. We sought to provide insights into the phenomenon of EOV after it was observed in young healthy subjects, including athletes, after the administration of dual autonomic blockade (DAB). From 29 participants who completed cardiopulmonary exercise testing (CPET) with and without DAB (0.04 mg/kg atropine and 0.2 mg/kg metoprolol), 5 subjects developed EOV (age = 29 ± 5 years; 3/5 were athletes) according to American Heart Association criteria. For each case, we identified 2 non-EOV healthy controls (age = 34.2 ± 8.3; 7/10 were athletes) that were subsequently age- and sex-matched. No participants had EOV during exercise without DAB. The 5 participants (4 male, 1 female) who demonstrated EOV with DAB had lower mean tidal volume (1.7 ± 0.5 L/min vs. 1.8 ± 0.5 L/min; p = 0.04) compared to participants in the non-EOV group and a decrease in peak tidal volume (2.9 ± 0.6 L/min to 2.2 ± 0.7 L/min; p = 0.004) with DAB. There were few other differences in CPET measures between EOV and non-EOV participants, although the PETCO2 tended to be higher in the EOV group (p = 0.07). EOV can be elucidated in young healthy subjects, including athletes, during cardiopulmonary exercise testing, suggesting that it may not be an ominous sign in all populations.

Bigaran, A, Howden, EJ, Foulkes, S, Janssens, K, Beaudry, R, Haykowsky, MJ, La Gerche, A, Fraser, SF, and Selig, SE. Prescribing exercise in early-stage breast cancer during chemotherapy: a simple periodized approach to align with the cyclic phases of chemotherapy. J Strength Cond Res 36(10): 2934-2941, 2022-To evaluate whether a periodized aerobic and resistance training plan aligned to the anthracycline chemotherapy (AC) cycles would be well tolerated, feasible, and attenuate the decline in peak oxygen uptake (V̇o2peak) in breast cancer (BC) patients. Twenty-eight women with early-stage BC treated with AC self-selected to undertake exercise training (EX 47 ± 9 years, n = 14) or usual care (53 ± 9 years, n = 14) for 12 weeks as part of a nonrandomized controlled trial. The periodized EX was aligned to the cyclic phases of AC, including AC taper and nontaper weeks. Outcome measures included cardiopulmonary exercise testing. Attendance and adherence variables (relative dose intensity [RDI] and volume load) were calculated to quantify the dose of EX completed relative to the amount of EX prescribed. The mean session attendance was 76% (range 46-88%). The mean ± SD prescribed and completed dose of aerobic training was 332.3 ± 48.7 MET h·wk-1 and 380.6 ± 53.2 MET h·wk-1 (p = 0.02), equating to a mean RDI of 89 ± 17%. For resistance training, the prescribed and completed cumulative dose was 128,264 ± 54,578 and 77,487 ± 26,108 kg (p0.001), equating to an RDI of 60 ± 11%. Adherence to the AC taper week RDI (52 ± 14%) for resistance training was significantly lower than the non-AC taper week (72 ± 8%, p = 0.02). The most frequent cause for EX interruption was hospitalization (35%), whereas AC-related illness was the most common cause for missed (57%) or modified EX sessions (64%). This periodized approach was mostly well tolerated for patients with BC. We speculate that a periodized approach may be both more palatable and useful, although this requires further investigation in a randomized controlled trial.

Cancer therapy related cardiac dysfunction (CTRCD) is an area of increasing focus, particularly during the survivorship period, for paediatric, adolescent and adult cancer survivors. With the advent of immunotherapy and targeted therapy, there is a new set of mechanisms from which paediatric and young adult patients with cancer may suffer cardiovascular injury. Furthermore, cardiovascular disease is the leading cause of morbidity and mortality in the survivorship period. The recently established Australian Cardio-Oncology Registry is the largest and only population-based cardiotoxicity database of paediatric and adolescent and young adult oncology patients in the world, and the first paediatric registry that will document cardiotoxicity caused by chemotherapy and novel targeted therapies using a prospective approach. The database is designed for comprehensive data collection and evaluation of the Australian practice in terms of diagnosis and management of CTRCD. Using the Australian Cardio-Oncology Registry critical clinical information will be collected regarding predisposing factors for the development of CTRCD, the rate of subclinical left ventricular dysfunction and transition to overt heart failure, further research into protectant molecules against cardiac dysfunction and aid in the discovery of which genetic variants predispose to CTRCD. A health economic arm of the study will assess the cost/benefit of both the registry and cardio-oncology clinical implementation. Finally, an imaging arm will establish if exercise cardiac magnetic resonance imaging and VO2 max testing is a more sensitive predictor of cardiac reserve in paediatric and adolescent and young adult oncology patients exposed to cardiac toxic therapies.

In the healthy, untrained young adult, a case is made for a respiratory system (airways, pulmonary vasculature, lung parenchyma, respiratory muscles, and neural ventilatory control system) that is near ideally designed to ensure a highly efficient, homeostatic response to exercise of varying intensities and durations. Our aim was then to consider circumstances in which the intra/extrathoracic airways, pulmonary vasculature, respiratory muscles, and/or blood-gas distribution are underbuilt or inadequately regulated relative to the demands imposed by the cardiovascular system. In these instances, the respiratory system presents a significant limitation to O2transport and contributes to the occurrence of locomotor muscle fatigue, inhibition of central locomotor output, and exercise performance. Most prominent in these examples of an “underbuilt” respiratory system are highly trained endurance athletes, with additional influences of sex, aging, hypoxic environments, and the highly inbred equine. We summarize by evaluating the relative influences of these respiratory system limitations on exercise performance and their impact on pathophysiology and provide recommendations for future investigation.

This study sought to explore the feasibility and utility of post-mortem coronary artery calcium (CAC) scoring in identifying patients with ischemic heart disease as cause of sudden death. 100 deceased patients aged 18–50 years underwent post-mortem examination in the setting of sudden death. At post-mortem, fifty cases were determined to have ischemic heart disease, and fifty had death attributed to trauma or unascertained causes. The CAC score was calculated in a blinded manner from post-mortem CTs performed on all cases. CAC scores were assessable in 97 non-decomposed cases (feasibility 97%). The median CAC score was 88 Agatston units [IQR 0–286] in patients deceased from ischemic heart disease vs 0 [IQR 0–0] in patients deceased from other causes (p 100 (n = 22) had ischemic heart disease as the cause of death. Fifteen cases had a CAC score of zero but severe coronary disease at post-mortem examination. Post-mortem CAC scoring is highly feasible. An elevated CAC score in cases 18–50 years old with sudden death predicts ischemic heart disease at post-mortem examination. However, a CAC score of zero does not exclude significant coronary artery disease. Post-mortem CAC score may be considered as a further assessment tool to help predict likely cause of death when there is an objection to or unavailability of post-mortem examination.

Athletes sometimes experience transient arrhythmias during intense exercise, which may be difficult to capture with traditional Holter monitors. New and highly portable technology, such as smartphone electrocardiogram (ECG) devices, may be useful in documenting and contribute to diagnosis of exercise-induced arrhythmias. There are little data available regarding the new Kardia 6 lead device (6L) and no data regarding its use in athletic populations. In this short communication, we present pilot data from 30 healthy athletes who underwent a 12‑lead ECG and subsequent 6L reading. Our pilot data show relatively high levels of agreement for QTc and PR interval and QRS duration, with the 6L readings slightly but significantly shorter on average.

Background Paroxysmal atrial fibrillation (PAF) is associated with cardioembolic risk, however events may occur during sinus rhythm (SR). 4D-flow cardiac magnetic resonance (CMR) imaging allows visualisation of left atrial blood flow, to determine the residence time distribution (RTD), an assessment of atrial transit time. Objective To determine if atrial transit time is prolonged in PAF patients during SR, consistent with underlying atrial stasis. Method 91 participants with PAF and 18 healthy volunteers underwent 4D flow analysis in SR. Velocity fields were produced RTDs, calculated by seeding virtual ‘particles’ at the right upper pulmonary vein and counting them exiting the mitral valve. An exponential decay curve quantified residence time of particles in the left atrium, and atrial stasis was expressed as the derived constant (RTDTC) based on heartbeats. The RTDTC was evaluated within the PAF group, and compared to healthy volunteers. Results Patients with PAF (n = 91) had higher RTDTC compared with gender-matched controls (n = 18) consistent with greater atrial stasis (1.68 ± 0.46 beats vs 1.51 ± 0.20 beats; p = .005). PAF patients with greater thromboembolic risk had greater atrial stasis (median RTDTC of 1.72 beats in CHA₂DS₂-VASc≥2 vs 1.52 beats in CHA₂DS₂-VASc Conclusions Atrial stasis quantified by 4D flow is greater in PAF, correlating with higher CHA₂DS₂-VASc scores. Female gender and systolic dysfunction are associated with atrial stasis. RTD offers an insight into atrial flow that may be developed to provide a personalised assessment of thromboembolic risk.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a group of cardiomyopathies associated with ventricular arrhythmias predominantly arising from the right ventricle, sudden cardiac death and right ventricular failure, caused largely due to inherited mutations in proteins of the desmosomal complex. Whilst long recognised as a cause of sudden cardiac death (SCD) during exercise, it has recently been recognised that intense and prolonged exercise can worsen the disease resulting in earlier and more severe phenotypic expression. Changes in cardiac structure and function as a result of exercise training also pose challenges with diagnosis as enlargement of the right ventricle is commonly seen in endurance athletes. Advice regarding restriction of exercise is an important part of patient management, not only of those with established disease, but also in individuals known to carry gene mutations associated with development of ARVC.

Aims Physical activity reduces cardiovascular disease burden and mortality, although its relationship with cardiac arrhythmias is less certain. The aim of this study was to assess the association between self-reported physical activity and atrial fibrillation (AF), ventricular arrhythmias and bradyarrhythmias, across the UK Biobank cohort. Methods and results We included 402 406 individuals (52.5% female), aged 40–69 years, with over 2.8 million person-years of follow-up who underwent self-reported physical activity assessment computed in metabolic equivalent-minutes per week (MET-min/wk) at baseline, detailed physical assessment and medical history evaluation. Arrhythmia episodes were diagnosed through hospital admissions and death reports. Incident AF risk was lower amongst physically active participants, with a more pronounced reduction amongst female participants [hazard ratio (HR) for 1500 vs. 0 MET-min/wk: 0.85, 95% confidence interval (CI) 0.74–0.98] than males (HR for 1500 vs. 0 MET-min/wk: 0.90, 95% CI 0.82–1.0). Similarly, we observed a significantly lower risk of ventricular arrhythmias amongst physically active participants (HR for 1500 MET-min/wk 0.78, 95% CI 0.64–0.96) that remained relatively stable over a broad range of physical activity levels between 0 and 2500 MET-min/wk. A lower AF risk amongst female participants who engaged in moderate levels of vigorous physical activity was observed (up to 2500 MET-min/wk). Vigorous physical activity was also associated with reduced ventricular arrhythmia risk. Total or vigorous physical activity was not associated with bradyarrhythmias. Conclusion The risk of AF and ventricular arrhythmias is lower amongst physically active individuals. These findings provide observational support that physical activity is associated with reduced risk of atrial and ventricular arrhythmias.

Key Points: 1. Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disease affecting the right, and/or the left ventricle, and commonly presents as an electrical disorder with ventricular arrhythmias and increased risk of sudden cardiac death. 2. ARVC cannot be diagnosed by a single test, and is a clinical diagnosis supported by electrophysiologic, morpho-functional, genetic, and histological data based on the 2010 Task Force 2 criteria. 3. Familial involvement occurs in more than 50%, and referral to a specialist centre with access to genotyping is appropriate in selected cases. 4. Implantable cardioverter-defibrillator (ICD) therapy carries risk, and appropriate thresholds should apply before offering this, particularly in younger individuals.

Exercise Doppler echocardiography (EDE) is a well-validated tool in ischemic and valvular heart diseases. However, its use in the assessment of the right heart and pulmonary circulation unit (RH-PCU) is limited. The aim of this study is to assess the semi-recumbent bicycle EDE feasibility for the evaluation of RH-PCU in a large multi-center population, from healthy individuals and elite athletes to patients with overt or at risk of developing pulmonary hypertension (PH). From January 2019 to July 2019, 954 subjects [mean age 54.2 ± 16.4years, range 16–96, 430 women] underwent standardized semi-recumbent bicycle EDE with an incremental workload of 25 watts every 2min, were prospectively enrolled among 7 centers participating to the RIGHT Heart International NETwork (RIGHT-NET). EDE parameters of right heart structure, function and pressures were obtained according to current recommendations. Right ventricular (RV) function at peak exercise was feasible in 903/940 (96%) by tricuspid annular plane systolic excursion (TAPSE), 667/751 (89%) by tissue Doppler-derived tricuspid lateral annular systolic velocity (S′) and 445/672 (66.2%) by right ventricular fractional area change (RVFAC). RV—right atrial pressure gradient [RV–RA gradient = 4 × tricuspid regurgitation velocity2 (TRV)] was feasible in 894/954 patients (93.7%) at rest and in 816/954 (85.5%) at peak exercise. The feasibility rate in estimating pulmonary artery pressure improved to more than 95%, if both TRV and/or right ventricular outflow tract acceleration time (RVOT AcT) were considered. In high specialized echocardiography laboratories semi-recumbent bicycle EDE is a feasible tool for the assessment of the RH-PCU pressure and function.

OBJECTIVE To evaluate exercise-related glucose and counterregulatory responses (CRR) in adults with type 1 diabetes with impaired awareness of hypoglycemia (IAH) using hybrid closed-loop (HCL) insulin delivery to maintain glucose homeostasis. RESEARCH DESIGN AND METHODS Twelve participants undertook 45-min high-intensity intermittent exercise (HIIE) and moderate-intensity exercise (MIE) in random order. The primary outcome was continuous glucose monitoring (CGM) time in range (70–180 mg/dL) for 24-h post–exercise commencement. RESULTS CGM time in range was similar for HIIE and MIE (median 79.5% [interquartile range 73.2, 87.6] vs. 76.1% [70.3, 83.9], P = 0.37), and time with levels CONCLUSIONS IAH adults using HCL undertaking HIIE and MIE exhibit heterogeneity in CRR. Novel findings were a preserved cortisol response and variable catecholamine responses to HIIE.

Several athletic programs incorporate echocardiography during pre-participation screening of American Style Football (ASF) players with great variability in reported echocardiographic values. Pre-participation screening was performed in National Collegiate Athletic Association Division I ASF players from 2008 to 2016 at the Division of Sports Cardiology. The echocardiographic protocol focused on left ventricular (LV) mass, mass-to-volume ratio, sphericity, ejection fraction, and longitudinal Lagrangian strain. LV mass was calculated using the area-length method in end-diastole and end-systole. A total of two hundred and thirty players were included (18±1 years, 57% were Caucasian, body mass index 29±4 kg/m2) after four players (2%) were excluded for pathological findings. Although there was no difference in indexed LV mass by race (Caucasian 78±11 vs. African American 81±10 g/m2, p=0.089) or sphericity (Caucasian 1.81±0.13 vs. African American 1.78±0.14, p=0.130), the mass-to-volume ratio was higher in African Americans (0.91±0.09 vs. 0.83±0.08, p

Anthracycline-based chemotherapy (AC) is a common treatment for patients with breast cancer and has been associated with a dramatic improvement in breast cancer survivorship. Among patients with early-stage breast cancer, cardiovascular diseases represent the most common cause of mortality, and

BACKGROUND: Circadian and multiday rhythms are found across many biological systems, including cardiology, endocrinology, neurology, and immunology. In people with epilepsy, epileptic brain activity and seizure occurrence have been found to follow circadian, weekly, and monthly rhythms. Understanding the relationship between these cycles of brain excitability and other physiological systems can provide new insight into the causes of multiday cycles. The brain-heart link has previously been considered in epilepsy research, with potential implications for seizure forecasting, therapy, and mortality (i.e., sudden unexpected death in epilepsy). METHODS: We report the results from a non-interventional, observational cohort study, Tracking Seizure Cycles. This study sought to examine multiday cycles of heart rate and seizures in adults with diagnosed uncontrolled epilepsy (N=31) and healthy adult controls (N=15) using wearable smartwatches and mobile seizure diaries over at least four months (M=12.0, SD=5.9; control M=10.6, SD=6.4). Cycles in heart rate were detected using a continuous wavelet transform. Relationships between heart rate cycles and seizure occurrence were measured from the distributions of seizure likelihood with respect to underlying cycle phase. FINDINGS: Heart rate cycles were found in all 46 participants (people with epilepsy and healthy controls), with circadian (N=46), about-weekly (N=25) and about-monthly (N=13) rhythms being the most prevalent. Of the participants with epilepsy, 19 people had at least 20 reported seizures, and 10 of these had seizures significantly phase locked to their multiday heart rate cycles. INTERPRETATION: Heart rate cycles showed similarities to multiday epileptic rhythms and may be comodulated with seizure likelihood. The relationship between heart rate and seizures is relevant for epilepsy therapy, including seizure forecasting, and may also have implications for cardiovascular disease. More broadly, understanding the link between multiday cycles in the heart and brain can shed new light on endogenous physiological rhythms in humans. FUNDING: This research received funding from the Australian Government National Health and Medical Research Council (investigator grant 1178220), the Australian Government BioMedTech Horizons program, and the Epilepsy Foundation of America's 'My Seizure Gauge' grant. ispartof: EBIOMEDICINE vol:72 ispartof: location:Netherlands status: published

Background The diagnostic yield of post-mortem interrogation of cardiac implantable electronic devices (CIEDs) including pacemakers, defibrillators and implantable loop recorders has not been well described. Methods We reviewed all post-mortem CIED interrogations performed by our statewide Institute of Forensic Medicine between 2005–2020 for investigation of sudden or unexplained death. Results 260 patients (68.8% male, median age 72.8 years [IQR 62.7–82.2]) underwent post-mortem CIED interrogation (202 pacemakers, 56 defibrillators and 2 loop recorders). CIEDs were implanted for a median of 2.0 [IQR 0.75–5] years, with 19 devices requiring replacement (and 5 end of life). Post-mortem interrogation was successful in 256 (98.5%) cases. Potential CIED malfunction was identified in 21 (8.1%) cases: untreated ventricular arrhythmias (n=13), lead failures (n=3) and battery depletion (n=5). CIED interrogation directly informed cause of death in 130 (50.0%) cases, with fatal ventricular arrhythmias identified in 121 patients (46.5%). In retrospect, 72 (27.7%) patients had abnormalities recorded by their device in the 30 days preceding death: non-sustained ventricular tachycardia (n=26), rapid atrial fibrillation (n=17), longevity concerns (n=22), intrathoracic impedance alarms (n=3), lead issues (n=3) or therapy delivered (n=1). In 6 cases where the patient was found deceased after a prolonged time, CIED interrogation accurately determined time of death. In one case, CIED interrogation was the primary method of patient identification. Conclusion Post-mortem CIED interrogation frequently contributes important information regarding critical device malfunction, pre-mortem abnormalities, cause and time of death or patient identity. Device interrogation should be considered for select patients with CIEDs undergoing autopsy. Funding Acknowledgement Type of funding sources: None.

Cardiac disease is a leading cause of death in systemic sclerosis (SSc) and sudden cardiac death (SCD) is thought to occur more commonly in SSc than in the general population. Diffuse myocardial fibrosis, myocarditis and ischaemic heart disease are all prevalent in SSc and can be reasonably hypothesised to contribute to an increased risk of SCD. Despite this, SCD remains a relatively understudied area of SSc with little understood about SSc-specific risk factors and opportunities for primary prevention. In this review, we present an overview of the possible mechanisms of SCD in SSc and our current understanding of how each of these mechanisms may contribute to cardiac death. This review highlights the need for a future research agenda that addresses the underlying epidemiology of SCD in SSc and identifies opportunities for intervention to modify the disease course of heart disease in SSc. ispartof: DIAGNOSTICS vol:11 issue:10 ispartof: location:Switzerland status: published

OBJECTIVE To compare glucose control with hybrid closed-loop (HCL) when challenged by high intensity exercise (HIE), moderate intensity exercise (MIE), and resistance exercise (RE) while profiling counterregulatory hormones, lactate, ketones, and kinetic data in adults with type 1 diabetes. RESEARCH DESIGN AND METHODS This study was an open-label multisite randomized crossover trial. Adults with type 1 diabetes undertook 40 min of HIE, MIE, and RE in random order while using HCL (Medtronic MiniMed 670G) with a temporary target set 2 h prior to and during exercise and 15 g carbohydrates if pre-exercise glucose was RESULTS Median TIR was 81% (67, 93%), 91% (80, 94%), and 80% (73, 89%) for 0–14 h post–exercise commencement for HIE, MIE, and RE, respectively (n = 30), with no difference between exercise types (MIE vs. HIE; P = 0.11, MIE vs. RE, P = 0.11; and HIE vs. RE, P = 0.90). Time-below-range was 0% for all exercise bouts. For HIE and RE compared with MIE, there were greater increases, respectively, in noradrenaline (P = 0.01 and P = 0.004), cortisol (P < 0.001 and P = 0.001), lactate (P ≤ 0.001 and P ≤ 0.001), and heart rate (P = 0.007 and P = 0.015). During HIE compared with MIE, there were greater increases in growth hormone (P = 0.024). CONCLUSIONS Under controlled conditions, HCL provided satisfactory glucose control with no difference between exercise type. Lactate, counterregulatory hormones, and kinetic data differentiate type and intensity of exercise, and their measurement may help inform insulin needs during exercise. However, their potential utility as modulators of insulin dosing will be limited by the pharmacokinetics of subcutaneous insulin delivery.

Cardiomyopathies (CM) are a heterogeneous group of muscle heart diseases, divided into 3 main categories (dilated, hypertrophic, and restrictive). In addition to these subgroups, athlete's heart and hypertensive cardiopathy are both the result of heart adaptation to increased loading conditions, making it possible to include them in the CM group. Right heart involvement is clear in some CM as arrhythmogenic CM, carcinoid syndrome, and endomyocardial fibrosis, whereas in others, like hypertrophic or dilated CM, it is known that the right heart has a prognostic impact but less clear is its pathogenic role.

Background:Exertional intolerance is a limiting and often crippling symptom in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Traditionally the pathogenesis has been attributed to central factors, including ventilation/perfusion mismatch, increased pulmonary vascular resistance, and right heart dysfunction and uncoupling. Pulmonary endarterectomy and balloon pulmonary angioplasty provide substantial improvement of functional status and hemodynamics. However, despite normalization of pulmonary hemodynamics, exercise capacity often does not return to age-predicted levels. By systematically evaluating the oxygen pathway, we aimed to elucidate the causes of functional limitations in patients with CTEPH before and after pulmonary vascular intervention.Methods:Using exercise cardiac magnetic resonance imaging with simultaneous invasive hemodynamic monitoring, we sought to quantify the steps of the O2transport cascade from the mouth to the mitochondria in patients with CTEPH (n=20) as compared with healthy participants (n=10). Furthermore, we evaluated the effect of pulmonary vascular intervention (pulmonary endarterectomy or balloon angioplasty) on the individual components of the cascade (n=10).Results:Peak Vo2(oxygen uptake) was significantly reduced in patients with CTEPH relative to controls (56±17 versus 112±20% of predicted;P2cascade, including O2delivery (product of cardiac output and arterial O2content), skeletal muscle diffusion capacity, and pulmonary diffusion. The total O2extracted in the periphery (ie, ΔAVo2[arteriovenous O2content difference]) was not different. After pulmonary vascular intervention, peak Vo2increased significantly (from 12.5±4.0 to 17.8±7.5 mL/[kg·min];P=0.036) but remained below age-predicted levels (70±11%). The O2delivery was improved owing to an increase in peak cardiac output and lung diffusion capacity. However, peak exercise ΔAVo2was unchanged, as was skeletal muscle diffusion capacity.Conclusions:We demonstrated that patients with CTEPH have significant impairment of all steps in the O2use cascade, resulting in markedly impaired exercise capacity. Pulmonary vascular intervention increased peak Vo2by partly correcting O2delivery but had no effect on abnormalities in peripheral O2extraction. This suggests that current interventions only partially address patients’ limitations and that additional therapies may improve functional capacity.

AIMS: Identifying early right ventricular (RV) dysfunction and impaired vasodilator reserve is challenging in heart failure with preserved ejection fraction (HFpEF). We hypothesized that cardiac magnetic resonance (CMR)-based exercise imaging and serial cyclic guanosine monophosphate (cGMP) measurements can identify dynamic RV-arterial uncoupling and responsiveness to pulmonary vasodilators at early stages of the HFpEF syndrome. METHODS AND RESULTS: Patients with HFpEF (n = 16), impaired left ventricular relaxation due to concentric remodelling (LVCR, n = 7), and healthy controls (n = 8) underwent CMR at rest and during supine bicycle exercise with simultaneous measurements of central haemodynamics and circulating cGMP levels, before and after oral administration of 50 mg sildenafil. At rest, mean pulmonary artery pressures (mPAP) were higher in HFpEF, compared with LVCR and controls (27 ± 2, 18 ± 1, and 11 ± 1, respectively; P = 0.01), whereas biventricular volumes, heart rate, and stroke volume were similar. During exercise, LVCR and HFpEF had a greater increase in the ratio of mPAP over cardiac output than controls (5.50 ± 0.77 and 6.34 ± 0.86 vs. 2.24 ± 0.55 in controls, P = 0.005). The ratio of peak exercise to rest RV end-systolic pressure-volume, a surrogate of RV contractility, was significantly reduced in LVCR and HFpEF (2.32 ± 0.17 and 1.56 ± 0.08 vs. 3.49 ± 0.35 in controls, P

Funding Acknowledgements Type of funding sources: None. Background While athletes are generally very fit, intense exercise can increase the risk of atrial fibrillation (AF), resulting in distressing symptoms during or after exercise. Moreover, other arrhythmias such as atrial flutter or supraventricular tachycardia (SVT) can also cause troublesome, exercise-related symptoms. Accurate diagnosis is essential to guide appropriate treatment. Given the symptoms are infrequent and/or occur in specific circumstances, traditional monitoring devices are often impractical to use during exercise or too invasive. Recently, smartphone ECGs such as the Alivecor KardiaMobile device (iECG) has been shown to be interpretable by a cardiologist in 95% of cases and may be the portable tool required to help identify arrhythmias in this challenging population. Purpose This case series was designed to highlight the use of iECG devices in aiding the diagnosis of arrhythmias in exercise-related symptoms. Methods Five cases are reported where the iECG was used to document at least one episode of exercise-related symptoms. Participants were eligible if they were over 18 years of age and had had an iECG trace taken during an episode of exercise-related symptoms (e.g. light-headedness, shortness of breath, palpitations). which could be associated with an arrhythmia All participants were identified by authors from previous clinical experiences (or from clinical colleagues) and provided written, informed consent. Results The cases included one amateur middle-distance runner in his 40s, two amateur ultra-endurance runners in their 30s and two young elite cricketers (Figure 1). In four of the cases, an accurate diagnosis of an arrhythmia (atrial flutter, AF and 2x SVT) was obtained using the iECG device, which helped to guide definitive treatment (e.g. medication or ablation). Two of these cases had been investigated using traditional methods such as stress ECG or Holter monitor over many months without achieving a diagnosis. The final case did not obtain a cardiac diagnosis using the iECG device despite using it on multiple occasions during symptomatic events. This reassured this athlete that the symptoms experienced were not cardiac related and she is now confident to exercise. Conclusion The iECG was able to accurately detect arrhythmias and provide a diagnosis in cases where traditional monitoring had not. The utility of detecting no arrhythmia during symptoms in one case was also highlighted, providing the athlete with the confidence to continue exercising. This reassurance and confidence across all cases is perhaps the most valuable aspect of this device, where clinicians and athletes can be more certain of reaching a diagnosis and undertaking appropriate management. Abstract Figure 1: iECG traces

Funding Acknowledgements Type of funding sources: None. Background Sudden cardiac death (SCD) during physical exercise is uncommon but devastating. Purpose We aimed to determine risk factors, causes and circumstances of sports and exercise-related SCD in the young in Australia. Methods We retrospectively reviewed the National Coronial Information System (NCIS) registry for deaths in Australia relating to cardiovascular disease (CVD) in cases aged 10 to 35 years between 2000-2016. Included cases had been undertaking sports or physical exercise at time of event. We collected baseline demographics and circumstances of death including location, type of physical exercise, whether the event was witnessed, and engagement of bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use prior to ambulance arrival. Results Over a 17-year period, 1,925 SCD cases were identified of which 110 cases (6%) related to sports/physical exercise were included in final analysis. Median age was 27 years (interquartile range [IQR] 21-32 years) with most being male (92%). Median BMI was 27 kg/m2 (IQR, 23-30) with 13 cases (12%) occurring in active athletes. Most common causes were coronary artery disease (CAD; 37%) and sudden arrhythmic death syndrome (SADS; 20%). Australian Rules Football (24%), running/jogging (14%) and soccer (14%) were the most frequently practiced at time of event. Prior symptoms were present in 39% (chest pain 37%, presyncope/syncope 26%). Most were witnessed (87%) with bystander CPR in 70%. AED use prior to ambulance arrival was 8%. Conclusions This study demonstrates the high occurrence of CAD and SADS in exercise-related SCD in the young. Although events were commonly witnessed, an AED was seldom used prior to ambulance arrival highlighting an important opportunity to improve outcomes in the post-arrest chain of survival.

Funding Acknowledgements Type of funding sources: None. Introduction Cardiac rehabilitation (CR) is a multi-disciplinary, evidence-based intervention, aimed to address modifiable risk factors for coronary artery disease. It is recommended worldwide for patients following myocardial infarction (MI), Percutaneous Coronary Intervention (PCI) and cardiac surgery. A growing body of evidence points towards a lack of uptake in CR in females and younger people. Purpose To examine the effectiveness of contemporary CR programs and assess whether they cater for all patients regardless of age, gender and prior level of fitness, via systematic review, meta-analysis and meta-regression. Methods MEDLINE was examined for studies involving exercise prescription or CR following MI, PCI and cardiac surgery from January 2010 to May 2020. RCTs and cohort studies of ≥10 patients were included for programs delivering phase II or III CR. Primary outcome measures were peakVO2max, 6-minute walk test (6MWT) and Metabolic Equivalent of Task (METs). Data were extracted using random effects meta-analysis. Epidemiological data were analysed for age, proportion of males to females and prior level of fitness. Baseline level of fitness was assessed by peakVO2max, 6MWT and METs values on entry into CR programs. Meta-regression was then used to determine change in fitness and the influence of age or gender. Results Thirty-three of the 713 studies (13 RCT, 20 cohort) were eligible and included in the review. Participants had a mean age of 60.0 years and 6/49 (12%) of study groups had a mean age CRF improved in all study groups by the end of CR programs (mean improvement in peakVO2 3.3mL/kg/min, 6MWT 90.8m and METs 1.7). Meta-regression analysis showed that males were more likely to have an increase in 6MWT distance compared to females (mean difference 3.16m (95% CI 0.44-5.89). However, gender and age did not independently affect peakVO2max or METs. Conclusion CR following MI, PCI or cardiac surgery improved mean CRF in all study groups. While males were more likely to show an improvement in 6MWT there was no appreciable difference in effect in other outcomes after controlling for age or gender differences. Females, younger people and those of average or above CRF appear to be under-represented in data and attendance at cardiac rehabilitation. Given that CR outcomes are equal across gender and age, more effort should be made to encourage female and younger patients to attend. A ‘Precision Medicine’ model of exercise prescription may assist in this aim.

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JO is supported by an Australian Government Research Training Program scholarship. CS is the recipient of a National Health and Medical Research Council (NHMRC) Practitioner Fellowship (#1154992). Background Athletes sometimes experience transient arrhythmias during intense exercise, which may be difficult to capture with traditional monitors. New highly portable technology, such as smartphone electrocardiogram (ECG) devices, may be useful in documenting and diagnosing exercise-induced arrhythmias. Accuracy of the Kardia single-lead ECG (1L) has been documented, but little data exists for the 6-lead device (6L). Purpose To examine the level of similarity between resting 6L and 12L readings to build evidence for the utility of the 6L as a practical diagnostic tool in athletes. Methods Participants (n = 30 healthy athletes, mean age 18.9 years, 57% male) had a resting supine 12-lead ECG (12L) as part of cardiac screening required by their sport. Within 1 hour, a 30 second 6L reading (leads I, II, III, aVR, aVL, aVF) was taken whilst seated. Data were analysed by 4 expert cardiologists. Manual measurements were taken for PR, QT and RR intervals and QRS duration using EPS digital calipers. To calculate mean 6L RR interval and QT prior to QTc, Continuous variables were expressed as the mean of 4 cardiologists’ values ± standard deviation. Two-tailed paired t-tests were used to compare continuous variables (p Results There were relatively high levels of agreement between the mean 6L and 12L measures for QTc and PR interval and QRS duration, with the 6L readings slightly but significantly shorter on average. The largest difference was seen in the QTc intervals (391ms vs 401ms, p = 0.003). The 6L QRS durations were shorter on average by 3ms (89ms vs 92ms, p = 0.025) and PR intervals were shorter on average by 6ms (163ms vs 169ms, p There was complete agreement for all cardiologists for sinus rhythm and the presence of ectopics for the 6L and 12L readings. Conclusions The 6L readings had relatively high agreement with the 12L. All 6L measures (except heart rate) were slightly shorter on average than 12L. These small differences are unlikely to have any clinical significance, and are similar to findings comparing the 1L to 12L. 6L heart rates were slightly higher, which is best explained by seated compared to lying position. The reading with the greatest variation was QT interval, some of which is explained by heart rate variation. These pilot data suggest the 6L is sufficiently accurate to be useful in an athletic population as an event monitor for exercise-induced arrhythmias. This may provide more useful diagnostic data than the 1L. Larger studies showing higher levels of agreement with 12L would be required to expand the role of 6L beyond an event monitor. Abstract Figure 1: 6L device, Bland-Altman plots

This article provides an overview of the recommendations from the Sports Cardiology section of the European Association of Preventive Cardiology on sports participation in individuals with valvular heart disease (VHD). The aim of these recommendations is to encourage regular physical activity including sports participation, with reasonable precaution to ensure a high level of safety for all affected individuals. Valvular heart disease is usually an age-related degenerative process, predominantly affecting individuals in their fifth decade and onwards. However, there is an increasing group of younger individuals with valvular defects. The diagnosis of cardiac disorders during routine cardiac examination often raises questions about on-going participation in competitive sport with a high dynamic or static component and the level of permissible physical effort during recreational exercise. Although the natural history of several valvular diseases has been reported in the general population, little is known about the potential influence of chronic intensive physical activity on valve function, left ventricular remodelling pulmonary artery pressure, and risk of arrhythmia. Due to the sparsity of data on the effects of exercise on VHD, the present document is largely based on clinical experience and expert opinion.

Many sporting teams, leagues and federations now mandate cardiac screening of athletes. The most common screening protocol in Australian sports involves a personal/family history and physical examination, together with a resting 12-lead ECG.1 Some bodies, such as the Union Cycliste Internationale, the England and Wales Cricket Board and the UK Football Association also mandate two-dimensional transthoracic echocardiography as part of the standard screen. While echocardiography is sometimes used as a screening tool, the variable use of this modality in cardiac screening programmes raises the issue of when this test should be used as a diagnostic tool for the follow-up evaluation of other screening abnormalities. There is a need for clear consensus guidance, which should take into account the additional costs, as well as the potential benefits of echocardiography and the potential harms of incidental findings. We audited the national cardiac screening programme of elite men’s and women’s Australian cricket.2 The protocol consists of history, physical examination and ECG. Overall, 2.0% of ECGs were abnormal or had ≥2 borderline findings according to the international criteria for athlete ECG interpretation,3 although 5.5% of cases had an echocardiogram, which …

Exercise capacity is frequently reduced in people with diabetes mellitus (DM), and the contribution of pulmonary microvascular dysfunction remains undefined. We hypothesized that pulmonary microvascular disease, measured by a novel exercise echocardiography technique termed pulmonary transit of agitated contrast (PTAC), would be greater in subjects with DM and that the use of pulmonary vasodilator agent sildenafil would improve exercise performance by reducing right ventricular afterload. Forty subjects with DM and 20 matched controls performed cardiopulmonary exercise testing and semisupine exercise echocardiography 1 h after placebo or sildenafil ingestion in a double-blind randomized crossover design. The primary efficacy end point was exercise capacity (V̇o2peak) while secondary measures included pulmonary vascular resistance, cardiac output, and change in PTAC. DM subjects were aged 44 ± 13 yr, 73% male, with 16 ± 10 yr DM history. Sildenafil caused marginal improvements in echocardiographic measures of biventricular systolic function in DM subjects. Exercise-induced increases in pulmonary artery systolic pressure and pulmonary vascular resistance were attenuated with sildenafil, while heart rate (+2.4 ±1.2 beats/min, P = 0.04) and cardiac output (+322 ± 21 ml, P = 0.03) improved. However, the degree of PTAC did not change ( P = 0.93) and V̇o2peak did not increase following sildenafil as compared with placebo (V̇o2peak: 31.8 ± 9.7 vs. 32.1 ± 9.5 ml·min−1·kg−1, P = 0.42). We conclude that sildenafil administration causes modest acute improvements in central hemodynamics but does not improve exercise capacity. This may be due to the mismatch in action of sildenafil on the pulmonary arteries rather than the distal pulmonary microvasculature and potential adverse effects on peripheral oxygen extraction. NEW & NOTEWORTHY This is one of the largest and most comprehensive studies of cardiopulmonary exercise performance in people with diabetes mellitus and to our knowledge the first to assess the effect of sildenafil using detailed echocardiographic measures during incremental exercise. Sildenafil attenuated the rise in pulmonary vascular resistance while augmenting cardiac output and intriguingly heart rate, without conferring any improvement in exercise capacity. The enhanced central hemodynamic indexes may have been offset by reduced peripheral O2 extraction.

PURPOSE: Anthracycline chemotherapy (AC) is associated with acute reductions in cardiopulmonary fitness (V˙O2peak). We sought to determine whether changes in V˙O2peak and cardiac function persisted at 12 months post-AC completion, and whether changes in cardiac function explain the heightened long-term heart failure risk. METHODS: Women with breast cancer scheduled for AC (n = 28) who participated in a nonrandomized trial of exercise training (ET; n = 14) or usual care (UC; n = 14) during AC completed a follow-up evaluation 12 months post-AC completion (16 months from baseline). At baseline, 4 months, and 16 months, participants underwent a resting echocardiogram (left ventricular ejection fraction; global longitudinal strain), a blood sample (troponin; B-type natriuretic peptide), a cardiopulmonary exercise test, and cardiac MRI measures of stroke volume (SV), heart rate, and cardiac output (Qc) at rest and during intense exercise. RESULTS: Seventeen women (UC, n = 8; ET, n = 9) completed evaluation at baseline, 4 months, and 16 months. At 4 months, AC was associated with 18% and 6% reductions in V˙O2peak in the UC and ET groups, respectively, which persisted at 16 months (UC, -16%; ET, -7%) and was not attenuated by ET (interaction, P = 0.10). Exercise Qc was lower at 16 months compared with baseline and 4 months (P < 0.001), which was due to a blunted augmentation of SV during exercise (P = 0.032; a 14% reduction in peak SV), with no changes in heart rate response. There was a small reduction in resting left ventricular ejection fraction (baseline to 4 months) and global longitudinal strain (between 4 and 16 months) and an increase in troponin (baseline to 4 months), but only exercise Qc was associated with V˙O2peak (R = 0.47, P < 0.01). CONCLUSION: Marked reductions in V˙O2peak persisted 12 months after anthracycline-based chemotherapy, which was associated with impaired exercise cardiac function. CLINICAL TRIAL REGISTRATION: ACTRN12616001602415.

Background The most important determinant of long-term survival in patients with idiopathic pulmonary fibrosis is the right ventricular (RV) adaptation to the increased pulmonary vascular resistance. Our aim was to explore RV contractile reserve during stress echocardiography in early-stage IPF. Methods Fifty early-stage patients with IPF and 50 healthy control patients underwent rest and stress echocardiography, including RV two-dimensional speckle tracking echocardiography. At peak exertion, blood gas analysis and spirometry were also assessed. Results At rest, RV diameters were mildly increased in IPF; however, although RV conventional systolic function indexes were similar between the IPF and control groups, RV global longitudinal strain and RV lateral wall longitudinal strain (LWLS) were significantly reduced in the IPF cohort. During physical exercise, patients with IPF showed a reduced exercise tolerance with lower maximal workload (P o 2; P Conclusions RV myocardial dysfunction is already present at rest in early-stage IPF and worsens during exertion as detected by two-dimensional speckle-tracking echocardiography. The RV altered contractile reserve appears to be related to reduced exercise tolerability and impaired pulmonary hemodynamic.

Athletes enjoy excellent health outcomes including greater longevity relative to non-athletic counterparts. Paradoxically, however, endurance athletic conditioning is associated with an increase in some arrhythmias. This review discusses the potential mechanisms for this paradox and strategies enabling early identification of potentially serious pathologies. Screening remains contentious due to the challenges of identifying relatively rare entities amongst a healthy cohort. The imperfect diagnostic accuracy of all current tests means that screening strategies have potential for harm through incorrect diagnoses as well as the potential for identification of important sub-clinical pathologies. Management of athletes at risk of ventricular arrhythmias and sudden cardiac death is similarly complex. There is much yet to learn about the specific patterns of ventricular arrhythmias in athletes, and the separation of benign from potentially life-threatening remains imperfect. There are some promising advances, however, such as specialised imaging modalities combined with improved electrophysiological diagnostics and therapeutics. Some unique clinical patterns are emerging to advance our understanding and management of athletes with ventricular arrhythmias, requiring specialised skillsets for evaluation and management.

Objectives This study sought to determine the impact of regular alcohol consumption on left atrial (LA) mechanical and reservoir function. Background Earlier studies suggest that regular alcohol intake is associated with increased atrial fibrillation (AF) and LA dilatation. Methods This study prospectively enrolled 160 patients with paroxysmal or persistent AF to undergo 3-T cardiac magnetic resonance (CMR) imaging in sinus rhythm. Patients self-reported alcohol consumption in standard drinks (∼12 g alcohol) per week over the preceding 12 months and were categorized into 4 groups: 1) lifelong nondrinkers; 2) mild drinkers (3 to 10 standard drinks/week); 3) moderate drinkers (11 to 20 standard drinks/week); 4) heavy drinkers (>20 standard drinks/week). Permanent AF and cardiomyopathy were excluded. On CMR, maximum LA volume (LAmax) and minimum LA volume (LAmin), global LA emptying fraction (LAEF) as (LAmax − LAmin) / LAmax, and LA reservoir function as (LAmax − LAmin) / LAmin were calculated. Results Regular alcohol consumption (mean 15.8 ± 6.9 standard drinks/week, n = 120) was associated with larger LA size (LA volume index 50 ± 13 ml/m2 vs. 43 ± 12 ml/m2; p = 0.005), reduction in LAEF (40 ± 14% vs. 52 ± 15%; p Conclusions In patients with AF, habitual alcohol consumption is associated with significantly increased LA size and atrial mechanical dysfunction compared with nondrinkers.

IntroductionLow and moderate endurance exercise is associated with better control of cardiovascular risk factors, a decreased risk of coronary artery disease and atrial fibrillation (AF). There is, however, a growing proportion of individuals regularly performing strenuous and prolonged endurance exercise in which the health benefits have been challenged. Higher doses of endurance exercise have been associated with a greater coronary atherosclerotic plaque burden, risk of AF and myocardial fibrosis (MF).Methods and analysisMaster@Heart is a multicentre prospective cohort study aiming to assess the incidence of coronary atherosclerosis, AF and MF in lifelong endurance athletes compared to late-onset endurance athletes (initiation of regular endurance exercise after the age of 30 years) and healthy non-athletes.The primary endpoint is the incidence of mixed coronary plaques. Secondary endpoints include coronary calcium scores, coronary stenosis >50%, the prevalence of calcified and soft plaques and AF and MF presence. Tertiary endpoints include ventricular arrhythmias, left and right ventricular function at rest and during exercise, arterial stiffness and carotid artery intima media thickness.Two hundred male lifelong athletes, 200 late-onset athletes and 200 healthy non-athletes aged 45–70 will undergo comprehensive cardiovascular phenotyping using CT, coronary angiography, echocardiography, cardiac MRI, 12-lead ECG, exercise ECG and 24-hour Holter monitoring at baseline. Follow-up will include online tracking of sports activities, telephone calls to assess clinical events and a 7-day ECG recording after 1 year.Ethics and disseminationLocal ethics committees approved the Master@Heart study. The trial was launched on 18 October 2018, recruitment is complete and inclusions are ongoing.Trial registration numberNCT03711539.