The benefits of exercise for cardiovascular and general health are many. However, sudden cardiac death (SCD) may occur in apparently healthy athletes who perform at the highest levels. A diverse spectrum of diseases is implicated in SCD in athletes, and while atherosclerotic coronary artery disease predominates in individuals of >35 years of age, primary cardiomyopathies and ion channelopathies are prevalent in young individuals. Prevention of SCD in athletes relies on the implementation of health policies aimed at the early identification of arrhythmogenic diseases (such as cardiac screening) and successful resuscitation (such as widespread utilization of automatic external defibrillators and training members of the public on cardiopulmonary resuscitation). This review will focus on the epidemiology and aetiologies of SCD in athletes, and examine fallacies in the approach to this controversial field. Furthermore, potential strategies to prevent these tragic events will be discussed, analysing current practice, gaps in knowledge and future directions.

Background Macular Integrity Assessment (MAIA) microperimetry is increasingly used in clinical and research settings to assess point retinal sensitivity and fixation stability. Testing occurs under mesopic conditions, commonly after a period of dark adaptation. Our aim was to identify the minimum length of adaptation required to optimise microperimetry performance. Methods MAIA microperimetry using the 10-2 grid was performed on 40 right eyes of 40 healthy participants aged 18–73 with no ocular pathology and vision of at least 0.1 logMAR after ambient light exposure, with 0, 5, 10, 15, 20 and 30 min of adaptation in mesopic settings. Ten right eyes of 10 participants with choroideremia were also tested following 0 and 20 min of adaptation. We further tested 10 right eyes of 10 healthy participants after bright light exposure, with 0, 10 and 20 min of adaptation. We compared changes in threshold sensitivity and fixation stability across time points. Results Microperimetry performance did not improve with increasing adaptation time in healthy participants or patients with choroideremia after ambient light exposure. After bright light exposure, we found microperimetry thresholds improved after 10 min of adaptation, but did not improve further at 20 min. Conclusion Mesopic adaptation is not required before MAIA microperimetry after exposure to ambient light. Ten minutes of adaptation is sufficient after exposure to a bright light stimulus, such as ophthalmoscopy or retinal imaging. The brief time of dark adaptation required corresponds to cone adaptation curves and provides further evidence for cone-mediated central retinal function under mesopic conditions.

Variance in procalcitonin levels have previously been proposed to differentiate systemic inflammation of bacterial origin from viral origin in community acquired pneumonia and sepsis, with a significant rise indicating bacterial infection.^5,6 The lack of a procalcitonin rise in viral infections may be due to virus-stimulated production of interferon-γ by macrophages, which inhibits TNF-α in the immune response.⁵ The presence of lower procalcitonin levels has been shown to have a 94% negative predictive value for bacterial co-infection in intensive care unit patients with confirmed influenza A(H1N1)pdm09.⁷ Therefore, we suggest that raised procalcitonin observed in COVID-19 could be due either to bacterial co-infection, which is itself causing increased severity and driving systemic sepsis, or as a direct marker of a more severe or widespread viral infection.

Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiac condition, often caused by mutations in genes encoding desmosomal proteins. The pathologic hallmark of the disease is a fibrofatty replacement of the myocardium, which constitutes the substrate for potentially fatal ventricular arrhythmias. ACM is one of the most common etiology of sudden cardiac death in athletes and young individuals. Although it is well established that regular exercise confers multiple health benefits and better survival in the general population, intense exercise may accelerate the phenotypic expression and the propensity to ventricular arrhythmias in patients with ACM. This review discusses current evidence regarding the safety and the effects of exercise in ACM. We scrutinize research findings based on animal and human models that raise concerns on the possible detrimental role of intense exercise in this condition. Finally, we examine the current knowledge on exercise prescription focusing on the optimal amount of exercise that should be recommended to patients with ACM.

Key Clinical Message. Tension pneumothorax is an uncommon presentation in patients with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) or COVID-19 pneumonia. We present a case of tension pneumothorax in a patient with COVID-19 pneumonia and myocarditis. This was an unlikely diagnosis in a patient with no known underlying lung condition and no other precipitating factors such as barotrauma. In an acute deterioration of patients with SARS-CoV-2, it is important to always consider alternative diagnoses and repeat imaging.

Percutaneous coronary intervention with stenting is followed by a duration of dual antiplatelet therapy (DAPT) to reduce stent thrombosis and avoid target lesion failure. The period of DAPT recommended in international guidelines following drug-eluting stent implantation is 12 mo for most patients with acute coronary syndrome, and 6 mo for patients with chronic coronary syndrome or high bleeding risk. The new generation of drug-eluting stents have metallic platforms with thinner struts, associated with significantly less stent thrombosis. Shortened DAPT has been investigated with these stents, with evidence from randomised clinical trials for some individual stents showing non-inferior safety and efficacy outcomes. This has to be balanced by the effect of DAPT on secondary prevention of systemic cardiovascular disease especially in high-risk populations. This review will outline the current evidence for individual stents with regards to DAPT duration for both acute coronary syndrome and chronic coronary syndrome and discuss further directions for research and personalised medicine in this contemporary percutaneous coronary intervention era.