bluuebunny/crossref_metadata_2025 huggingface dataset:
Peptic ulcer disease
Authors: Sung Joseph
Published: February 2020

Helicobacter pylori infection, use of nonsteroidal anti-inflammatory drugs (NSAIDs) including aspirin, and smoking are the most important causes of peptic ulcer disease. Peptic ulcer disease is characterized by a history of waxing and waning symptoms of localized, dull, aching pain in the upper abdomen. Bleeding is the most common complication; free perforation of the stomach or duodenum into the peritoneal cavity is uncommon but serious. The diagnosis of peptic ulcer disease is made by endoscopy, which offers an opportunity for biopsy of gastric ulcers (which may be malignant) and reveals important prognostic indicators in patients with bleeding ulcers. A single daily dose of a proton pump inhibitor gives quick relief of symptoms and effective healing of peptic ulcers in 4 to 6 weeks. The management of patients with upper gastrointestinal haemorrhage requires a multidisciplinary medical and surgical approach. Early risk stratification based on clinical and endoscopic criteria allows delivery of appropriate care, with endoscopic intervention now widely accepted as the first line of therapy. This should be followed by administration of a high dose of an intravenous proton pump inhibitor to further reduce recurrent bleeding. Treatment of H. pylori is a cure for peptic ulcer disease in most patients. This usually requires at least two antimicrobial agents, with the most popular triple therapy combining a proton pump inhibitor with any two of amoxicillin, metronidazole, and clarithromycin for 7 to 14 days. Eradication of H. pylori infection, avoidance of high-dose NSAIDs or aspirin, and the maintenance use of proton pump inhibitors in high-risk individuals are the best ways to prevent recurrence of ulcer and ulcer complications.
Carcinoid syndrome
Authors: Khoo B. , Tan T.M. , Bloom S.R.
Published: February 2020

Carcinoid syndrome is a paraneoplastic syndrome caused by the release of 5-hydroxytryptamine (5-HT or serotonin) and other vasoactive substances from neuroendocrine tumours (NETs), typically those arising from the duodenum, jejunum, ileum, and also from bronchial NETs. Characteristic clinical features, which typically arise when tumours have metastasized to the liver, are flushing and secretory diarrhoea, and occasionally wheezing. Carcinoid crisis is an acute and life-threatening manifestation with sustained flushing, hyperdynamic shock, and acute kidney injury. Carcinoid heart disease typically manifests in the right side of the heart with valvular insufficiency and heart failure. Diagnosis is made by a combination of the characteristic clinical syndrome, biochemical markers such as 5-hydroxyindoleacetic acid (a metabolite of 5-HT), histopathological examination of tissue from tumour deposits, and imaging with conventional cross-sectional modalities as well as somatostatin receptor scintigraphy. Treatment is most often directed at control of symptoms, with the standard of care for control of the carcinoid syndrome being a somatostatin analogue. Symptomatic therapies are used to palliate diarrhoea. Niacin supplements should be given to forestall the development of pellagra. Multiple modalities for treatment of NETs exist, which should be directed by a multidisciplinary team. Their general prognosis is good with median overall survival of 9.3 years, but the presence of carcinoid syndrome cuts this to 5.0 years, and less in the presence of heart disease.
Differential diagnosis and investigation of malabsorption
Authors: Forbes Alastair , Mulcahy Victoria
Published: February 2020

Malabsorption is defined as defective mucosal absorption in the intestine, with clinical presentation ranging from diarrhoea or steatorrhoea with massive weight loss, through to abdominal bloating, fatigue, changes in bowel habit, or anaemia. There are many causes, but the commonest in adult life are coeliac disease, Crohn’s disease, and bile salt malabsorption. Simple blood tests may prompt suspicion of malabsorption, will sometimes go a long way to providing a diagnosis, and will guide further investigation with specific tests, for example, serum antibody to tissue transglutaminase (coeliac disease), endoscopic examinations, imaging studies, breath tests, and tests of bile salt absorption. Treatment for malabsorption is directed (where possible) to the underlying cause as specific agents to address the malabsorption itself are lacking. General nutritional support and replacement of individual deficiencies are crucial.
Coeliac disease
Authors: Mooney Peter D. , Sanders David S.
Published: February 2020

Coeliac disease is a common disorder of the small intestine in which storage proteins in dietary wheat, rye, and barley (gliadin, secalins, and hordeins, usually referred to as ‘gluten’) induce an autoimmune enteropathy characterized by villous atrophy in genetically susceptible individuals. The prevalence of coeliac disease is 0.2 to 2% in populations with high consumption of gluten-containing foods. Females are more commonly affected than males (1.5–2:1), with typical presentation now in the forties. ‘Classical’ coeliac disease presented in childhood with malabsorption, but this is now rare. ‘Nonclassical’ presentations are now the norm, and highly variable, ranging from nonspecific abdominal symptoms to the consequences of malabsorption (e.g. anaemia, osteoporosis) to nongastrointestinal symptoms (e.g. ataxia, dermatitis herpetiformis), and many have no symptoms at all. Diagnosis is made by serological testing for (usually) antitissue transglutaminase antibodies, which have excellent sensitivity and specificity, with confirmation by duodenal biopsy. Treatment is with a gluten-free diet, which constitutes a major challenge for some people. Most patients (but not all) can eat pure oats. Complications include lymphoma, osteoporosis, and other autoimmune conditions. Patients have a normal life expectancy, although quality of life is adversely affected.
Effects of massive bowel resection
Authors: Middleton Stephen J. , Gabe Simon M. , Playford Raymond J.
Published: February 2020

Major vascular events involving the superior mesenteric artery and small-bowel volvulus are the commonest reasons for adults to require massive intestinal resection. The ability of the residual bowel to adapt after resection varies greatly between patients, but common postoperative problems include sepsis, diarrhoea (or high-output stoma losses), fluid and electrolyte imbalance, malnourishment (protein–energy malnutrition, mineral and vitamin deficiencies), gallstones, renal stones, and psychological illness. Where appropriate, oral nutrition, initially consisting of low-volume polymeric feeds administered by nasogastric or enteral tube, should be started within the first few days of surgery. Small-volume, frequent, solid or semisolid meals with low long-chain triglycerides and (when colon is in continuity) oxalate content should be introduced subsequently, and isotonic electrolyte solutions given as required. Oral multivitamin and mineral supplements are usually needed, and vitamin B12 injections may be required. There should be regular long-term monitoring of fat-soluble vitamins (A and D), vitamin B12, folate, magnesium, zinc, and bone status. Long-term intravenous nutrition is sometimes needed. Growth factor administration, especially glucagon-like peptide-2 analogues, may stimulate bowel adaptation. Small-bowel lengthening may be considered for patients with dilated bowel close to the length required. Those who are dependent on peripheral nutrition and develop complications such as loss of venous access or liver disease should be considered for intestinal transplantation.
Irritable bowel syndrome
Authors: Farmer Adam D. , Aziz Qasim
Published: February 2020

Symptoms suggestive of disturbed lower gastrointestinal function without adequate explanation are very common in adults in the Western world, up to 15% of whom experience such symptoms at any one time, although most do not seek medical advice. The currently used terms are best viewed as an attempt to provide some clinically useful, rather than pathophysiologically accurate, categorization of patients and their symptoms based on disordered gut–brain interactions. Irritable bowel syndrome is defined according to the Rome III criteria as recurrent abdominal pain or discomfort associated with a change in bowel habit for at least 6 months, with symptoms experienced on at least 3 days of at least 3 months. Many subtypes are recognized. Routine haematological and biochemical screening is usually performed on the assumption that it will be normal. Features that raise the suspicion of organic disease and indicate a need for further investigation include the onset of symptoms in middle-aged or older individuals, weight loss, or blood in the stool. Management remains empirical: no single pharmacological agent or group of agents has ever been found to be consistently effective. The principal task of the physician is to provide explanation and reassurance (sometimes supplemented by psychological treatments), but particular symptoms are often treated as follows: (1) constipation—defecation may be eased by supplementary dietary fibre and poorly absorbed fermentable carbohydrates which increase faecal bulk and soften the stool; osmotic laxatives and enemas are used for the severely constipated patient, as well as more novel agents; (2) diarrhoea—attention to diet is often helpful, as are simple antidiarrhoeal agents; and (3) abdominal pain—antispasmodics (e.g. hyoscine butyl bromide) are frequently used, as are antidepressants.
Colonic diverticular disease
Authors: Buchs Nicolas C. , Hompes Roel , Ashraf Shazad Q. , Mortensen Neil J.McC.
Published: February 2020

Colonic diverticula are herniations of mucosa through the bowel musculature. They are seen most often in the sigmoid and descending colon, with a prevalence of up to 65% in people over the age of 80 in European populations. They are uncommon in African and Asian countries, where the prevalence is only 0.2%. A lifelong diet deficient in dietary fibre is associated with their development, but it is not known why some diverticula become symptomatic. Diverticula are usually discovered incidentally, but symptoms which are attributable to diverticular disease include colicky abdominal pain and bloating, often accompanied by a change in bowel habit with the passage of broken, pellety stools after considerable straining. All patients with such presentation should be investigated to exclude rectal or sigmoid carcinoma. Treatment is with reassurance that there is no serious underlying disease, a high-fibre diet, and—for patients with pain—antispasmodics such as mebeverine. Elective resection may be indicated in the few patients who have repeated severe attacks. Complications of diverticular disease include diverticulitis, pericolic abscess formation, peritonitis, intestinal obstruction, haemorrhage, and fistula formation. Acute diverticulitis typically presents with pain and tenderness over the left lower abdomen, and the patient may have pyrexia, malaise, anorexia, and nausea. Treatment is with rest, broad-spectrum antibiotics, and analgesia. Resection of the sigmoid colon may be necessary if symptoms fail to resolve or recur, or for patients with complications (peritonitis, fistula, obstruction). Overall, percutaneous drainage, antibiotic treatment, and expectant policies have reduced the need for both acute and elective surgical treatment.
Congenital abnormalities of the gastrointestinal tract
Authors: Uhlig Holm H.
Published: February 2020

Congenital abnormalities of the gastrointestinal tract can be divided into macroscopic anatomical abnormalities and monogenically determined, high-penetrance functional defects that present either directly postnatally or during the first few months of life. On occasion, symptoms may be delayed for months or years even in patients with substantial anatomical defects. Anatomical and structural abnormalities can affect any part of the gut. These include oesophageal atresia and tracheo-oesophageal fistula, anterior abdominal wall defects, congenital pyloric stenosis, atresia and stenosis of the small intestine, duplication of the gastrointestinal tract, small intestinal malrotation with or without volvulus, small intestinal lymphangiectasia, Meckel’s diverticulum, congenital short intestine syndrome, colonic atresia, Hirschsprung’s disease, and imperforate anus. Meconium ileus is an intestinal obstruction that develops in utero, often associated with subsequent structural abnormalities. The widespread use of ultrasonography allows many abnormalities to be recognized prenatally. Presentation of structural congenital abnormalities of the gastrointestinal tract in adult life is uncommon, but small intestinal lymphangiectasia, Meckel’s diverticulum, or small intestinal obstruction can present beyond childhood. Functional congenital abnormalities include multiple genetic defects that cause congenital diarrhoea due to malabsorption and maldigestion, defects in enterocyte and enterochromaffin cell development, and autoimmune enteropathies. In addition, there is a group of genetic defects that predispose to development of extreme early infantile onset of inflammatory bowel disease. An interdisciplinary approach is required for the optimal management of children with complex congenital abnormalities.
Cancers of the gastrointestinal tract
Authors: Labib Peter L. , Bridgewater J.A. , Pereira Stephen P.
Published: February 2020

Cancers of the gastrointestinal tract are one of the most rewarding interfaces in translational medicine, leading to greater understanding of the genetic mechanisms leading to cancer and the development of novel targeted therapies. Diagnosis of gastrointestinal tract cancers is usually made or suspected at endoscopy and confirmed by biopsy. Oesophageal cancer is a common cancer, usually of squamous cell histology, that is particularly prevalent in East Asia and Southeast Africa. Typical presentation is with dysphagia. Overall survival at 5 years is 15%. Usually adenocarcinoma, stomach cancer is particularly prevalent in East Asia, Eastern Europe, and Western South America. Predisposing factors include Helicobacter pylori infection, low socioeconomic status, tobacco smoking, heavy alcohol use, and diet. Dysphagia, early satiety, and anaemia are common presenting features, with weight loss being an indication of advanced disease. Overall survival at 5 years is 18.9%. Colorectal cancer is the third most common cancer in men and second most common in women worldwide, and is predisposed to by a Western diet. Most cases arise by transformation of an adenoma to a carcinoma by sequential inherited and acquired mutations. Typical presentations of left-sided tumours are alteration in bowel habit, obstruction, or overt bleeding, whereas right-sided tumours often present with iron-deficiency anaemia. Overall survival at 5 years is now almost 60%.
Vascular disorders of the gastrointestinal tract
Authors: Boyapati Ray
Published: February 2020

A wide range of vascular disorders and vasculitides may affect the gastrointestinal tract. Most are quite uncommon, but presentations are often dramatic with intestinal bleeding or gangrene. Intestinal ischaemia is most commonly due to atherosclerosis or thrombosis causing arterial or venous mesenteric vascular occlusion. There are four primary syndromes. (1) Ischaemic colitis—presents with abdominal pain, nausea, vomiting, and tenderness followed by passage of loose bloody stool. Supportive management is usually sufficient, but a key challenge is early identification of patients with severe injury who are likely to progress to transmural ulceration and perforation. (2) Acute mesenteric ischaemia—typically presents with sudden abdominal pain, initially without localizing signs such that diagnosis is often delayed. Priorities of management are resuscitation, exclusion of other causes of apparent abdominal catastrophe, and prompt laparotomy to resect ischaemic bowel. (3) Chronic mesenteric ischaemia—most often caused by atherosclerotic disease and presents with severe and poorly localized cramping abdominal pain after eating. Diagnosis requires evidence of vascular occlusion on imaging, and revascularization is the definitive management strategy. (4) Mesenteric venous thrombosis—diagnosis is most commonly via cross-sectional imaging. The mainstay of treatment is supportive, as well as anticoagulation and a search for predisposing factors. Vasculitides affecting the intestine may be primary or secondary. Abdominal symptoms rarely dominate the clinical picture. Vascular lesions of the gastrointestinal tract may present with acute haemorrhage, chronic iron deficiency anaemia, or obstruction. Lesions include angiodysplasias, telangiectasias, haemangiomas, Dieulafoy lesions, and gastric antral vascular ectasia. These lesions may occur in isolation or as part of a syndrome (e.g. hereditary haemorrhagic telangiectasia).
Pathobiology of chronic liver disease
Authors: Mehal Wajahat Z.
Published: February 2020

Chronic liver disease is responsible for most of the clinical burden of liver disease. Chronic liver injury can occur via a variety of mechanisms, including sterile inflammation and activation of innate and adaptive immunity. Despite the diversity of disease aetiologies and the ability of the liver to regenerate, a significant minority of patients with chronic liver disease proceed to liver fibrosis and eventually cirrhosis, which is defined histologically by regenerative hepatocyte nodules surrounded by fibrous bands of matrix. Ongoing liver injury stimulates the development of a myofibroblast cell type which is responsible for matrix remodelling, haemodynamic changes, and immune cell regulation. This typically results in repair without significant modification of the basic liver structure. In a few subjects, this repair process results in alterations of the basic structure of the liver with loss of hepatocyte mass, deposition of collagen, and the development of hypertension in the portal venous system. Although cirrhosis is well defined histologically, there is a spectrum of severity. In early cirrhosis, patients are asymptomatic but with increasing derangement in hepatic function and portal hypertension, patients can decompensate and develop ascites, coagulopathy, encephalopathy, jaundice, renal failure, oesophageal varices, and spontaneous bacterial infections. Management is focused on removing or reducing ongoing liver injury, and managing cirrhosis-related complications by the use of low-salt diets, diuretics, β-blockers, endoscopic therapy, vasopressors, and antibiotics. There is, as yet, no definite role for antifibrotic medications.
Liver failure
Authors: Macnaughtan Jane , Jalan Rajiv
Published: February 2020

Liver failure occurs when loss of hepatic parenchymal function exceeds the capacity of hepatocytes to regenerate or repair liver injury. Acute liver failure is characterized by jaundice and prolongation of the prothrombin time in the context of recent acute liver injury, with hepatic encephalopathy occurring within 8 weeks of the first onset of liver disease. Acute-on-chronic liver failure is characterized by hepatic and/or extrahepatic organ failure in patients with cirrhosis associated with an identified or unidentified precipitating event. The commonest causes of acute liver failure are acute viral hepatitis and drugs. Acute-on-chronic liver failure is most commonly precipitated by infection, alcohol abuse, and superimposed viral infection. The main clinical manifestations are hepatic encephalopathy, coagulopathy, jaundice, renal dysfunction, and haemodynamic instability. Infection and systemic inflammation contribute to pathogenesis and critically contribute to prognosis. Specific therapy for the underlying liver disease is administered when available, but this is not possible for most causes of liver failure. Treatment is predominantly supportive, with particular emphasis on (1) correction or removal of precipitating factors; (2) if encephalopathy is present, using phosphate enemata, nonhydrolysed disaccharide laxatives, and/or rifaximin; (3) early detection and prompt treatment of complications such as hypoglycaemia, hypokalaemia, cerebral oedema, infection, and bleeding. The onset of organ failure should prompt discussion with a liver transplantation centre. The mortality of acute liver failure (without liver transplantation) is about 40%. Patients with acute liver failure who do not develop encephalopathy can be expected to recover completely. Those who recover from an episode of acute-on-chronic liver failure should be considered for liver transplantation because otherwise their subsequent mortality remains high.
Hepatitis A to E
Authors: Alexander Graeme J.M. , Nash Kate
Published: February 2020

The clinical picture with each of the five major hepatitis viruses A, B, C, D, and E depends firstly upon whether infection is acute, with resolution, or evolves into chronic infection; secondly, on the grade of hepatic inflammation; and thirdly, the stage of fibrosis. Acute icteric hepatitis is the most easily recognized consequence of infection and is generally a self-limited condition. In otherwise healthy individuals, only hepatitis B and C cause chronic viral hepatitis. In immunosuppressed individuals, hepatitis A can follow a protracted course, while hepatitis E can evolve to chronic infection. A specific diagnosis is made by the combination of serology and polymerase chain reaction. Uncomplicated cases recover spontaneously; there is no proven therapy to enhance recovery. Acute liver failure caused by viral hepatitis now has a good outcome, with liver transplantation available for those with poor parameters at onset. Protection against hepatitis A and B is available, both by active vaccination and (less often now) by passive administration of hepatitis B immunoglobulin preparations. Vaccines for hepatitis C are some distance away, but for hepatitis E are under investigation. Vaccination against hepatitis B also protects against hepatitis D.
Primary sclerosing cholangitis
Authors: Lynch Kate D. , Chapman Roger W.
Published: February 2020

Primary sclerosing cholangitis is a chronic cholestatic liver disease caused by diffuse inflammation and fibrosis that can involve the entire biliary tree. The cause is unknown, but it is presumed to be immune mediated, and there is a close association with inflammatory bowel disease, particularly ulcerative colitis. The disorder tends to affect men (male:female, 2:1), some presenting with fatigue, intermittent jaundice, weight loss, right upper quadrant pain, and pruritus, but many are asymptomatic at diagnosis, which is made incidentally when a persistently raised serum alkaline phosphatase is discovered, usually in the clinical setting of ulcerative colitis. Serum biochemical tests usually indicate cholestasis, but diagnosis is based on three criteria: (1) generalized beading and stenosis of the biliary system on cholangiography; (2) absence of choledocholithiasis or a history of bile duct surgery; and (3) exclusion of bile duct cancer, usually by prolonged follow-up. There is no curative medical treatment. Pruritus is initially managed with cholestyramine, with second-line treatments including rifampicin and naltrexone. Orthotopic liver transplantation is the only option available for young patients with advanced liver disease.
Tumours of the pancreas
Authors: Skipworth James R.A. , Pereira Stephen P.
Published: February 2020

Pancreatic cancer, most commonly in the form of a solid ductal adenocarcinoma, accounts for 3% of all cancers but ranks in the top five leading causes of cancer deaths in most developed countries, reflecting the fact that it has a very poor prognosis (median survival 6–9 months). It is a disease of older age (85% of patients >65 years), and commoner in smokers.

Most patients present with locally advanced or metastatic disease, often with obstructive jaundice. Pain is unusual in early disease, but when present is characteristically described as ‘gnawing’, ever present, and frequently radiating into the back. Weight loss is commonly due to anorexia as a result of jaundice or pain, but can occasionally be the only presenting symptom.

Serum biochemistry will typically show elevated bilirubin and a cholestatic picture of liver enzymes, with particular elevation of alkaline phosphatase and γ-glutamyl transferase. Transabdominal ultrasonography is usually the primary investigation in a patient with jaundice and can detect pancreatic tumours greater than 2 cm in size or hepatic metastases with a diagnostic accuracy of 75%, but identifies smaller tumours much less reliably. The essential investigations for the diagnosis and staging of pancreatic cancer are contrast-phased CT scan and occasionally MRI.

The only curative treatment for pancreatic cancer is surgical excision. This is technically feasible in up to 20% patients at presentation, but even after careful selection almost 40% of these will have positive microscopic resection margins, and overall postoperative survival is only around 10% at 5 years, the remainder experiencing metastatic disease in the peritoneum, liver, or lungs. Adjuvant chemotherapy with gemcitabine can double the 5-year survival rate. Palliative management may require biliary stenting for jaundice, duodenal stenting (or surgical bypass) for gastric outlet obstruction, pain control, and palliative chemotherapy.
Blood vessels and the endothelium
Authors: Channon Keith , Vallance Patrick
Published: February 2020

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

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

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

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

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

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

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

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

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

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

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

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

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 >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

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

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

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

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

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

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

Normal intracranial pressure is between 5 and 15 mm Hg in supine subjects. Intracranial hypertension (ICP >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

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

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

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.