Translational Sciences in Cardiac Failure Secondary to Arteriovenous Fistula in Hemodialysis Patients.

High-output cardiac failure is a rare form of heart failure associated with the formation of arteriovenous fistula (AVF) in hemodialysis patients. The pathophysiology underlying the HOCF is complex and multifactorial. Presence of AVF can cause long term hemodynamic changes that ultimately lead to increased cardiac output and consequently cardiac failure. A number of risk factors have been associated with the development of HOCF post-AVF construction, including male sex, a proximally located AVF and a state of volume overload. Dysregulation of tissue inhibitor of matrix metalloproteinase 4, Sirtuin-1 and Sirtuin-3 gene expression have been associated with the development of heart failure. The differences observed between genders have been attributed to altered activity of the ß-adrenoceptor system. Numerous biomarkers including cardiac troponin T and I, atrial natriuretic peptide, brain natriuretic peptide among others have shown both prognostic and diagnostic potential; however further research is needed to establish their utility in clinical practice for patients with AVF associated HOCF. In recent years risk stratification models have been developed to help identify patients at the highest risk of developing HOCF post AVF which could be revolutionary in its identification and management. Potential options for managing HOCF post-AVF include AVF ligation, banding and anastoplasty however these procedures are not without their own associated risks. In this review, we discuss the pathophysiology, risk stratification and management of patients with AVF associated HOCF.

At the heart of COVID-19.

Coronavirus disease (COVID-19) first presented in Wuhan, Hubei province, China in December 2019. Since then, it has rapidly spread across the world, and is now formally considered a pandemic. The disease does not discriminate but increasing age and the presence of comorbidities are associated with severe form of the disease and poor outcomes. Although the prevalence of COVID-19 in patients with cardiovascular disease is under-reported, there is evidence that pre-existing cardiac disease can render individuals vulnerable. It is thought that COVID-19 may have both a direct and indirect effect on the cardiovascular system; however, the primary mechanism of underlying cardiovascular involvement is still uncertain. Of particular interest is the role of angiotensin-converting enzyme 2, which is well known for its cardiovascular effects and is also considered to be important in the pathogenesis of COVID-19. With a range of different drug candidates being suggested, effective anti-virals and vaccines are an area of on-going research. While our knowledge of COVID-19 continues to rapidly expand, this review highlights recent advances in our understanding of the interaction between COVID-19 and the cardiovascular system.

Update on cardiac imaging: A critical analysis.

Imaging is instrumental in diagnosing and directing the management of atherosclerosis. In 1958 the first diagnostic coronary angiography (CA) was performed, and since then further development has led to new methods such as coronary CT angiography (CTA), optical coherence tomography (OCT), positron tomography (PET), and intravascular ultrasound (IVUS). Currently, CA remains powerful for visualizing coronary arteries; however, recent studies show the benefits of using other non-invasive techniques. This review identifies optimum imaging techniques for diagnosing and monitoring plaque stability. This becomes even direr now, given the rapidly rising incidence of atherosclerosis in society today. Many acute coronary events, including acute myocardial infarctions and sudden deaths, are attributable to plaque rupture. Although fatal, these events can be preventable. We discuss the factors affecting plaque integrity, such as increased inflammation, medications like statins, and increased lipid content. Some of these precipitating factors are identifiable through imaging. However, we also highlight significant complications arising in some modalities; in CA this can include ventricular arrhythmia and even death. Extending this, we elucidated from the literature that risk can also vary based on the location of arteries and their plaques. Promisingly, there are less invasive methods being trialled for assessing plaque stability, such as Cardiac Magnetic Resonance Imaging (CMR), which is already in use for other cardiac diseases like cardiomyopathies. Therefore, future research focusing on using imaging modalities in conjunction may be sensible, to bridge between the effectiveness of modalities, at the expense of increased complications, and vice versa.

Health inequalities in cardiopulmonary resuscitation and use of automated electrical defibrillators in out-of-hospital cardiac arrest.

Out of hospital cardiac arrest (OHCA) outcomes can be improved by strengthening the chain of survival, namely prompt cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED). However, provision of bystander CPR and AED use remains low due to individual patient factors ranging from lack of education to socioeconomic barriers and due to lack of resources such as limited availability of AEDs in the community. Although the impact of health inequalities on survival from OHCA is documented, it is imperative that we identify and implement strategies to improve public health and outcomes from OHCA overall but with a simultaneous emphasis on making care more equitable. Disparities in CPR delivery and AED use in OHCA exist based on factors including sex, education level, socioeconomic status, race and ethnicity, all of which we discuss in this review. Most importantly, we discuss the barriers to AED use, and strategies on how these may be overcome.

Letter to the editor in response to: achievement emotions of medical students: do they predict self-regulated learning and burnout in an online learning environment?

This letter summarises the perspectives of medical students in the United Kingdom (UK) on the research paper conducted by Wang and colleagues (2023) titled 'Achievement Emotions of Medical Students: Do They Predict Self-Regulated Learning and Burnout in an Online Learning Environment?'. Overall, we find this paper a positive contribution to the literature surrounding medical education. However, we have highlighted some weaknesses in the study design and proposed additional points for exploration in further iterations of this study. We hope the readership takes the time to read our letter and consider the points we have raised.

An update on Takotsubo syndrome.

ABSTRACT: Takotsubo syndrome (TTS) can be described as an acute, transiently occurring form of heart failure. It typically causes systolic dysfunction of the left ventricle (LV). Perhaps what is of most significance is the reversible nature of TTS, with many patients achieving recovery within a few weeks to months. TTS can be referred to by other names, attributed to its various precipitants, as well as the structural manifestations of the syndrome. Physical and emotional stressors have been identified as the most common of causes, hence the terms 'stress cardiomyopathy' and 'broken heart syndrome'. Precipitants can range from psychological, and hormonal, to molecular mechanisms. The symptoms of TTS can coalesce with other conditions and hence give rise to many differential diagnoses. Most patients present with dyspnoea and chest pain. The latter also presents in acute coronary syndrome (ACS); thus, ACS is a common differential diagnosis for TTS. The coronavirus disease 2019 (COVID-19) pandemic saw a drastic increase in mental health concerns which have persisted beyond this period. Further studies into personality disorders and their potential predisposition to COVID-19 and thus TTS would advance our understanding of the neuropsychiatric triggers of TTS. There is also a need for a single sensitive and specific diagnostic test for TTS as its diagnosis relies on the culmination of clinical presentation, echocardiography, cardiac catheterization, and cardiovascular magnetic resonance imaging (CMR).

Pedicled or skeletonized bilateral internal mammary artery harvesting - a meta- analysis and trial sequential analysis.

OBJECTIVE: There is varying evidence on the role of skeletonization of internal mammary artery in reducing the risk of sternal wound infections and ischemia following bilateral internal mammary artery grafting. Post-operative clinical outcomes of skeletonized bilateral internal mammary artery versus pedicled bilateral internal mammary artery harvesting in patients undergoing coronary artery bypass surgery were compared. METHODS: A comprehensive electronic search was conducted using MEDLINE, Scopus, EMBASE, Cochrane database and Google Scholar from inception until 15 June 2020. All studies directly comparing skeletonized and pedicled bilateral internal mammary artery harvesting were included. Meta-analysis and trial sequential analysis were conducted. RESULTS: Nine studies (one randomized controlled trial and eight observational studies) consisting of 3649 patients (2050 patients with skeletonized bilateral internal mammary artery grafting and 1599 patients with pedicled bilateral internal mammary artery grafting) were included. Pooled effects analysis and trial sequential analysis reported significantly lower risk of sternal wound infection with skeletonized bilateral internal mammary artery harvesting (OR 0.27, 95% CI 0.20-0.51, p < 0.00001). CONCLUSIONS: Skeletonization reduces the risk of sternal wound infections by preserving vasculature as much as possible. This facilitates its use in patients at high risk of sternal wound infection.

COVID-19 pandemic and its impact on service provision: A cardiology prospect.

Coronavirus disease 2019 (COVID-19) pandemic has significantly impacted the availability of cardiology services and management of cardiac conditions. Elective surgeries, outpatient appointments and cardiac imaging have been largely cancelled across the world due to the risk of infection transmission and the need for reallocation of resources to deal with the increasing number of COVID-19 patients. The impact on patients with cardiac co-morbidities during these times may be drastic. However, cardiologists and hospitals across the world have implemented measures to ensure on-going monitoring and care of patients remotely. In this review, we discuss the impact of COVID-19 on cardiac services including interventional cardiology services, cardiac imaging and outpatient appointments. In addition, implications for future research and clinical practice are also discussed.

Spontaneous coronary artery dissection: presentation and management options.

Coronary artery dissection is a serious, life-threatening heart condition. It can occur spontaneously or due to traumatic or iatrogenic causes. Spontaneous coronary artery dissection (SCAD) is often misdiagnosed as most patients present with symptoms resembling those of an acute coronary syndrome. Clinical sequelae of SCAD include debilitating morbidities such as myocardial infarction, myocardial ischaemia, sudden cardiac death, ventricular arrhythmias amongst many other myocardial ischaemia associated complications. There are two main methods of managing patients with SCAD; conservative management with medical therapy or revascularisation by percutaneous coronary intervention or coronary artery bypass grafting.

"Proximalization is Advancement"-Zone 3 Frozen Elephant Trunk vs Zone 2 Frozen Elephant Trunk: A Literature Review.

Over the decades, the Frozen Elephant Trunk (FET) technique has gained immense popularity allowing simplified treatment of complex aortic pathologies. FET is frequently used to treat aortic conditions involving the distal aortic arch and the proximal descending aorta in a single stage. Surgical preference has recently changed from FET procedures being performed at Zone 3 to Zone 2. There are several advantages of Zone 2 FET over Zone 3 FET including reduction in spinal cord injury, visceral ischemia, neurological and cardiovascular sequelae. In addition, Zone 2 FET is a technically less complicated procedure. Literature on the comparison between Zone 3 and Zone 2 FET is scarce and primarily observational and anecdotal. Therefore, further research is warranted in this paradigm to substantiate current surgical treatment options for complex aortic pathologies. In this review, we explore literature surrounding FET and the reasons for the shift in surgical preference from Zone 3 to Zone 2.

Dissection of coronary artery: A clinical overview.

Spontaneous coronary artery dissection (SCAD) is a rare but life-threatening disorder. SCAD is gaining importance as an emerging cause of acute coronary syndrome (ACS), especially in otherwise healthy young women. While SCAD and ACS show similarity in presentation, the management of SCAD differs to that of ACS. If not managed properly SCAD can lead to sudden death. This review examines the pathophysiology, clinical presentation, diagnostic algorithms, and the current and future management of SCAD.

Can symptoms of anosmia and dysgeusia be diagnostic for COVID-19?

OBJECTIVE: Olfactory and taste dysfunction (OTD) is a potential neurological manifestation of coronavirus-2019 (COVID-19). We aimed to investigate the diagnostic value of symptoms of anosmia and dysgeusia for COVID-19. METHODS: A comprehensive electronic search was conducted using PubMed, MEDLINE, Scopus, Cochrane database, and Google Scholar from 1 June 2020 to 12 June 2020. All studies reporting symptoms of anosmia and dysgeusia in COVID-19-positive patients were included. A total of 23 studies were included in the systematic review. RESULTS: Symptoms of anosmia and dysgeusia were frequently reported by COVID-19-positive patients. Symptoms were more common in females and in younger patients. There was no direct association between the severity of COVID-19 and the presence of symptoms. However, some evidence was found for a longer duration of these symptoms and increased severity of COVID-19 infection in young patients. CONCLUSION: OTD is commonly reported by COVID-19 patients. Due to limited literature on the association between OTD and COVID-19, it is currently not possible to conclude that these symptoms alone can be used to diagnose COVID-19. However, the presence of OTD can potentially be used as a screening tool for COVID-19 especially in young and female patients. Further research is required to establish the true diagnostic value of these symptoms and efficacy as screening tools for COVID-19 patients.