bluuebunny/crossref_metadata_2025_split huggingface dataset:
Blood vessels and the endothelium
Authors: Channon Keith , Vallance Patrick 
Published: February 2020

Abstract
The blood vessel wall consists of three layers: the intima, media, and adventitia. Not all vessels have each layer, and the layers vary in size and structure between vessels. The intima is made up of a single layer of endothelial cells on a basement membrane, beneath which—depending on vessel size—there may be a layer of fibroelastic connective tissue and an internal elastic lamina that provides both structure and flexibility. Embedded in the intima are pericytes. The media is made up of smooth muscle cells, elastic laminae, and extracellular matrix. The adventitia is the outermost part of the vessel, composed mainly of fibroelastic tissue but also containing nerves, small feeding blood vessels (the vasa vasorum), and lymph vessels. The adventitia is directly related to the surrounding perivascular adipose tissue.
Cardiac physiology
Authors: Evans Rhys D. , MacLeod Kenneth T. , Marston Steven B. , Severs Nicholas J. , Sugden Peter H. 
Published: February 2020

Abstract
The function of the heart is to pump sufficient oxygenated blood containing nutrients, metabolites, and hormones to meet moment-to-moment metabolic needs and preserve a constant internal environment. The heart has two essential characteristics—contractility and rhythmicity. The nervous system and neurohumoral agents modulate relationships between the venous return to the heart, the outflow resistance against which it contracts, the frequency of contraction, and its inotropic (contractile) state; there are also intrinsic cardiac autoregulatory mechanisms. An understanding of the molecular mechanisms governing cardiac cell behaviour and the mechanical, electrical, and hormonal control of the heart at a whole organ level is essential for the understanding of cardiac pathophysiology.
Chest pain, breathlessness, and fatigue
Authors: Dwight Jeremy 
Published: February 2020

Abstract
The symptoms of chest pain, breathlessness, and fatigue present a frequent diagnostic challenge in the outpatient and acute medical departments, as well as the emergency department. They have a broad differential diagnosis that includes several life-threatening pathologies. The cardiovascular history routinely includes assessment of risk factors and those aspects of the patient’s past medical history that make cardiovascular disease more likely. The presence of numerous risk factors may, on occasion, prompt the physician to proceed to further investigation even in the face of a relatively unconvincing history.
Most diagnoses are made on the basis of patient history, and the physician is always compelled to return to the initial history and examination to put the findings of any investigations into context and to plan therapy appropriate for the individual patient.
Echocardiography
Authors: Newton James D. , Banning Adrian P. , Mitchell Andrew R.J. 
Published: February 2020

Abstract
Ease of use, rapid data provision, portability, and safety mean that echocardiography has become the principal investigation for almost all cardiac conditions. A modern transthoracic echocardiography examination combines real-time two-dimensional (2D) imaging of the myocardium and valves with information about velocity and direction of blood flow obtained by Doppler and colour-flow mapping. A complete examination can be performed in most patients in less than 30 min. There are three main echocardiographic techniques: two-dimensional (cross-sectional), M-mode, and Doppler. Despite the rapid and substantial advances in ultrasound technology and the widespread use of echocardiography, it is important to recognize and understand the limitations of the technique. These include reliance on acoustic windows, evaluation at rest, subjective assessments, evaluation of complex structures such as the right ventricle remains a major challenge, and the fact that the scope of an ‘echo’ is broad.
Cardiac catheterization and angiography
Authors: Folland Edward D. 
Published: February 2020

Abstract
Cardiac catheterization/angiography is indicated for evaluation of patients with coronary, valvular, and congenital heart disease in whom diagnostic or therapeutic decisions cannot be made on the basis of non-invasive tests. Most patients presenting for cardiac catheterization have coronary artery disease: catheterization and coronary angiography are integral parts of interventional treatments for patients experiencing ischaemic coronary syndromes. Vascular access is usually obtained percutaneously from the femoral, radial, or brachial artery (for the left heart), or the femoral, internal jugular, or brachial/antecubital vein (for the right heart). Cardiac catheterization/angiography permits interventions, particularly coronary angioplasty/stenting, that are of great and increasing therapeutic importance. This chapter reviews the diagnostic applications of cardiac catheterization and angiography.
Epidemiology and general pathophysiological classification of heart failure
Authors: McDonagh Theresa A. , Guha Kaushik 
Published: February 2020

Abstract
Heart failure is a clinical syndrome caused by cardiac dysfunction, most commonly left ventricular systolic dysfunction. Patients with heart failure symptoms or signs and normal or near normal left ventricular function are often classified as having heart failure with preserved ejection fraction (HF-PEF), but there is no clear and generally accepted definition of this condition. Estimates of incidence and prevalence are heavily influenced by definition. Prevalence rises significantly with age, with a median age of first presentation in the mid-seventies. Longitudinal data suggests that the incidence of heart failure has remained fairly stable over the last few decades, but prevalence is increasing as more people survive cardiovascular disease earlier in life.
Cardiac transplantation and mechanical circulatory support
Authors: Parameshwar Jayan , Tsui Steven 
Published: February 2020

Abstract
Cardiac transplantation is the treatment of choice for selected patients with advanced heart failure: median survival approaches 12 years and recipients enjoy an excellent quality of life, but availability is severely limited by shortage of donor organs. The need for lifelong immunosuppression is associated with side effects, including an increased incidence of malignancy. Newer immunosuppressive agents reduce nephrotoxicity and delay the onset of cardiac allograft vasculopathy, but may produce other side effects. Ventricular assist devices are mechanical blood pumps that work in parallel or series with the native ventricles. First-generation volume-displacement pulsatile ventricular assist devices have been superseded by rotary blood pumps that generate continuous flow. Significant complications include bleeding, thromboembolism, device failure due to pump thrombosis, and infection.
Pericardial disease
Authors: Henein Michael 
Published: February 2020

Abstract
The most common clinical presentations of pericardial disease are pericarditis, effusion, tamponade, and constriction. With acute pericarditis, the most common proven causes are viral infection or as a complication of myocardial infarction, but a wide range of other conditions including autoimmune rheumatic disorders and tuberculosis need to be considered. With pericardial effusion, acute rapid collection is usually caused by traumatic injury, iatrogenic ventricular puncture, or aortic dissection. Presentation is with pericardial tamponade, which is a condition of haemodynamic instability caused by chamber compression because increased intrapericardial pressure is greater than the filling pressure of the right and left ventricles. Presentation is typically with shortness of breath or circulatory collapse. With pericardial constriction, a stiff pericardium loses its stretching ability to accommodate normal changes in intracardiac pressures. Most patients present with leg or abdominal swelling and dyspnoea.
Acute rheumatic fever
Authors: Carapetis Jonathan R. 
Published: February 2020

Abstract
Acute rheumatic fever is an immunologically mediated multisystem disease induced by recent infection with group A streptococcus. About 5% of people have the potential to develop acute rheumatic fever after infection by a strain of streptococcus with propensity to cause the condition. Most cases (97%) occur in low-income and some middle-income countries, with indigenous populations in some affluent countries also affected. Children aged 5–15 years are most commonly affected, and rheumatic heart disease remains the most common acquired heart disease of childhood in the world. Most medical practitioners in industrialized countries will rarely, if ever, see a case. However, the dramatic decline in incidence of acute rheumatic fever in industrialized countries during the second half of the 20th century was not replicated in many developing countries, or among some indigenous and other populations living in poverty in industrialized countries.
Cardiac disease in HIV infection
Authors: Currie Peter F. 
Published: February 2020

Abstract
Symptomatic heart disease can affect up to 10% of HIV-positive patients and cause death in around 2%. Cardiovascular screening and risk factor management is recommended.
In resource-poor countries where access to antiretroviral drugs is limited the typical manifestations are (1) HIV heart muscle disease—this occurs in the late stages of HIV infection, with dilated cardiomyopathy having a dismal prognosis, the median survival after diagnosis being about 100 days; standard therapy for heart failure should be considered; and (2) pericardial effusion—a common finding, but most are symptomless; significant effusions are often due to mycobacterial infection or malignant infiltration, particularly with non-Hodgkin’s lymphoma.
Cardiac involvement in genetic disease
Authors: Traill Thomas A. 
Published: February 2020

Abstract
Many clinicians find themselves faced, from time to time, with a patient who has a family history of a known disorder, such as Marfan syndrome, or who has non-cardiac features that suggest a syndrome. The first part of this chapter deals with developmental syndromes that include congenital cardiac defects, with coverage restricted to a few relatively common disorders that are seen in adult patients. The second part describes the two common connective tissue disorders—Marfan and Ehlers–Danlos syndromes—and the more recently described Loeys–Dietz syndrome that shares some pathogenetic mechanisms with Marfan. Some other heritable diseases that affect the heart are listed in a table, without discussion in the text: though they are important to other organ systems, they offer little opportunity to the cardiologist for diagnosis or management.
Management of stable angina
Authors: Timmis Adam D. 
Published: February 2020

Abstract
Angina—the pain provoked by myocardial ischaemia—is usually caused by obstructive coronary artery disease that is sufficiently severe to restrict oxygen delivery to the cardiac myocytes. Quality of life is impaired in direct proportion to the severity of symptoms.
Clinical history remains the most useful basis for diagnosis and referral decisions to specialist services, the commonest indications being (1) new-onset angina; (2) exclusion of angina in high-risk individuals with atypical symptoms; (3) worsening angina in a patient with previously stable symptoms; (4) new or recurrent angina in a patient with history of myocardial infarction or coronary revascularization; (5) assessment of occupational fitness (e.g. airline pilots). Cardiac investigation is usually unnecessary in patients with non-anginal chest pain, but residual diagnostic uncertainty can be resolved in those with atypical or typical angina by CT coronary angiography, which is now the non-invasive test of choice.
Coronary artery bypass and valve surgery
Authors: Sayeed Rana , Taggart David 
Published: February 2020

Abstract
The two main indications for coronary artery bypass grafting (CABG) are for relief of symptoms, usually angina and/or breathlessness, that persist even with optimal medical therapy, and/or prognosis. There is a prognostic benefit for CABG in patients with large volumes of ischaemia (i.e. affecting &gt;12% of the ventricular myocardium), and the benefit of revascularization increases with increasing volumes of ischaemia. The overall mortality for elective CABG in the United Kingdom is around 1% and has continued to fall over the last decade despite an increasingly adverse risk profile of patients undergoing surgery. Valve surgery is primarily performed for patients with severe valvular disease and symptoms. Indications also include deteriorating ventricular function and the requirement for coronary artery surgery in patients with coexistent valve disease. Mitral valve repair is a highly successful procedure in patients with non-rheumatic valvular regurgitation and is associated with an excellent long-term survival.
Therapeutic anticoagulation
Authors: Keeling David 
Published: February 2020

Abstract
The main indications for therapeutic anticoagulation are venous thromboembolism, deep vein thrombosis, and pulmonary embolism, and the prevention of stroke in patients with atrial fibrillation or mechanical heart valves. Low-molecular-weight heparins have largely replaced unfractionated heparin in its treatment. Their much more predictable anticoagulant response combined with high bioavailability after subcutaneous injection means that the dose can be calculated by body weight and given subcutaneously without any monitoring or dose adjustment. Their widespread use resulted in most patients with deep vein thrombosis being managed as outpatients, and this is also increasingly the case for uncomplicated pulmonary embolism. Oral direct inhibitors of anticoagulation that specifically target thrombin or factor Xa are increasingly used to treat acute venous thromboembolism and for stroke prevention in atrial fibrillation.
Secondary hypertension
Authors: Brown Morris J. , Mir Fraz A. 
Published: February 2020

Abstract
The term ‘secondary hypertension’ is used to describe patients whose blood pressure is elevated by a single, identifiable cause, with an important subdivision being into reversible and irreversible causes: clinically, it is important to exclude the former, but not necessarily to find the latter. In the first two decades of life, the prevalence of secondary hypertension is greater than that of essential hypertension; thereafter, a patient is much more likely to have essential hypertension, but investigations for secondary hypertension should still be assiduous in the twenties and thirties because the alternative entails so many years of tablet-taking. Overall, it is estimated that about 10% of all patients with hypertension may have a secondary cause. All patients with hypertension should have a minimum set of investigations.
Mendelian disorders causing hypertension
Authors: Samani Nilesh J. , Tomaszewski Maciej 
Published: February 2020

Abstract
Several rare mendelian disorders where hypertension is the predominant manifestation have been characterized at the molecular level. These include glucocorticoid-remediable aldosteronism, the syndrome of apparent mineralocorticoid excess, Liddle’s syndrome, and Gordon’s syndrome. Hypertension and hypokalaemia are features of 11β-hydroxylase and 17β-hydroxylase deficiency—two rare recessive gene disorders of adrenal steroid-synthesizing enzymes that, among others, cause congenital adrenal hyperplasia. 11β-Hydroxylase deficiency usually presents in infancy or early childhood with virilization of both sexes, while presentation of 17β-hydroxylase deficiency may be delayed until adolescence or adulthood. Hypertension due to a phaeochromocytoma may be a feature of multiple endocrine neoplasia type 2 (MEN2, Sipple’s syndrome), which when familial is inherited in an autosomal dominant pattern, or rarely to be a feature of neurofibromatosis (von Recklinghausen’s disease).
Chronic peripheral oedema and lymphoedema
Authors: Mortimer Peter S. 
Published: February 2020

Abstract
Lymph transport, not venous reabsorption, is the main process responsible for interstitial fluid drainage. Oedema develops when the microvascular filtration rate exceeds lymph drainage for a sufficient period, and any chronic oedema represents a failure of lymph drainage. In practice, any chronic oedema should be managed in the same way as lymphedema. The primary function of the lymphatic vessels is to drain the plasma filtrate within body tissues and return it to the blood circulation. Lymphatic vessels also have an important immune surveillance function, as they are the main drainage route from the tissues for immune active cells such as dendritic cells, lymphocytes, and macrophages. Intestinal lymphatics are responsible for fat absorption. Impaired lymphatic function leads to disturbed fluid homeostasis (swelling), dampened immune responses (infection), and disturbed fat homeostasis (increased peripheral fat deposition), all features of lymphoedema. Lymphatic vessels are also the preferential route for cancer spread.
Assessing and preparing patients with medical conditions for major surgery
Authors: Abbott Tom , Pearse Rupert 
Published: February 2020

Abstract
The assessment of patients before surgery is complex. However, since surgery is offered to increasing numbers of patients with multiple comorbidities, the demand for comprehensive preoperative assessment is expected to increase. Perioperative medicine provides a patient-centred approach from preoperative assessment through to hospital discharge and beyond. Preoperative assessment serves to identify comorbidity that may require optimization before surgery, plan perioperative care, identify a need for a non-standard anaesthetic technique, assess functional reserve, brief patients on the perioperative care pathway, and provide an opportunity to have questions answered. There are a variety of tools for preoperative assessment and recognized approaches to managing patients with existing chronic disease during the perioperative period, but the absence of robust evidence to favour any particular clinical approach is striking.
Circulation and circulatory support in the critically ill
Authors: Pinsky Michael R. 
Published: February 2020

Abstract
Cardiovascular dysfunction is common in critically ill patients and is the primary cause of death in a vast array of illnesses. The prompt identification and diagnosis of its probable cause, coupled to appropriate resuscitation and (when possible) specific treatments, are cornerstones of intensive care medicine. Cardiovascular performance can be assessed clinically at the bedside and through haemodynamic monitoring, and with therapeutic or other proactive interventions. Rapid assessment of shocked patients by bedside echocardiography is increasingly used in those institutions where equipment and expertise are available. Diagnostic approaches or therapies based on data derived from invasive haemodynamic monitoring in the critically ill patient assume that specific patterns of derangement reflect specific disease processes, which will respond to appropriate intervention.
Management of raised intracranial pressure
Authors: Menon David K. 
Published: February 2020

Abstract
Normal intracranial pressure is between 5 and 15 mm Hg in supine subjects. Intracranial hypertension (ICP &gt;20 mm Hg) is common in many central nervous system diseases and in fatal cases is often the immediate cause of death. Increases in intracranial volume and hence—given the rigid skull—intracranial pressure may be the consequence of brain oedema, increased cerebral blood volume, hydrocephalus, and space-occupying lesions. Brain perfusion depends on the cerebral perfusion pressure which is mean arterial pressure minus intracranial pressure. The normal brain autoregulates cerebral blood flow down to a lower limit of cerebral perfusion pressure of about 50 mm Hg in healthy subjects, and perhaps 60–70 mm Hg in disease. Cerebral perfusion pressure reduction to below these values results in cerebral ischaemia.
Diagnosis of death and organ donation
Authors: Murphy Paul 
Published: February 2020

Abstract
Death is the permanent loss of the capacity for consciousness and respiration, both of which are functions of the brain-stem. Death can be diagnosed by somatic, circulatory, or neurological criteria, which vary between countries and are influenced by prevailing attitudes towards death, legal frameworks, and available medical technologies. When organ retrieval is planned after circulatory death, there is need for a time-critical schedule for the diagnosis of death using circulatory criteria. These require the absence of consciousness and respiratory effort to be demonstrated, and emphasize the need for explicit clarity that resuscitation should not be instigated or continued, how the absence of the circulation should identified, and the minimum period of observation that is required to be assured that the possibility of spontaneous return of the circulation has passed.
Persistent problems and recovery after critical illness
Authors: Mikkelsen Mark E. , Iwashyna Theodore J. 
Published: February 2020

Abstract
Post-intensive care syndrome is defined as new or worsening impairment in cognition, mental health, or physical function that persists after a critical illness. The complexities of post-intensive care syndrome come from the interactions of the patient’s premorbid mental health and physical function, the acute physiologic derangements and acute organ injury of the critical illness, and the side effects of procedures, treatments, and potential complications incurred during the critical illness. Problems are better described as challenging syndromes rather than specific actionable diagnoses, with the four major functional problems for patients being weakness, cognitive impairment, psychological problems, and new or worsened organ dysfunction. The sequelae of critical illness often extend beyond patients and impact the families of critically ill patients.
Thoracic imaging
Authors: Copley Susan J. , Hansell David M. 
Published: February 2020

Abstract
Despite recent technological advances, chest radiography remains the cornerstone of thoracic imaging. The chest radiograph is justifiably regarded as an integral part of the examination of the patient in respiratory medicine. Because of the wealth of information available from chest radiography, careful interpretation of the chest radiograph remains a necessary clinical skill. Advances in cross-sectional imaging have had a great impact in improving the diagnosis of thoracic pathology, not only for the assessment of mediastinal disease but also in the evaluation of patients with suspected diffuse lung disease. Nevertheless, a chest radiograph should always be obtained and looked at carefully before submitting a patient to more sophisticated imaging techniques. In the case of CT, the expense and radiation burden are important considerations.
Nosocomial pneumonia
Authors: Lim Wei Shen 
Published: February 2020

Abstract
Nosocomial pneumonia is generally defined as a new pulmonary infiltrate on chest radiography, combined with evidence of infection expressed as fever, purulent respiratory secretions, and/or leucocytosis, with onset 48 hours or more after admission. It is the most frequent lethal nosocomial infection (overall mortality 7% in general ward inpatients to over 50% in critically ill patients). Most cases are caused by Gram-negative bacteria (50–70%) or Staphylococcus aureus (15–30%). Gram-negative bacteria reach the lung by aspiration of gastric contents or by microaspiration of upper airway secretions; throat cultures reveal that 60–75% of patients on intensive care units are colonized by these organisms (compared to 2–6% of healthy people).