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Who rapid advice guidelines for pharmacological management of sporadic human infection with avian influenza A (H5N1) virus generic vytorin 30mg amex cholesterol esterase definition. Eosinophilic meningitis caused by Angiostrongylus cantonensis: a case report and literature review vytorin 20 mg on-line cholesterol test dublin. Salmonella typhi infections in the United States discount vytorin 20 mg without prescription cholesterol rich foods, 1975–1984: increasing role of foreign travel 20mg vytorin for sale cholesterol lowering eating plan south africa. Relative efficacy of blood, urine, rectal swab, bone- marrow, and rose-spot cultures for recovery of Salmonella typhi in typhoid fever. Multidrug-resistant typhoid fever in children: epidemiology and therapeutic approach. Reduction of mortality in chloramphenicol-treated severe typhoid fever by high-dose dexamethasone. Global burden of Shigella infections: implications for vaccine development and implementation of control strategies. Acute liver failure: established and putative hepatitis viruses and therapeutic implications. Lamivudine therapy for severe acute hepatitis B virus infection after renal transplantation: case report and literature review. Leptospirosis—an emerging pathogen in travel medicine: a review of its clinical manifestations and management. Acute lung injury in leptospirosis: clinical and laboratory features, outcome, and factors associated with mortality. Leptospirosis as a cause of acute respiratory failure: clinical features and outcome in 35 critical care patients. Ceftriaxone compared with sodium penicillin g for treatment of severe leptospirosis. Acute pulmonary schistosomiasis in travelers returning from Lake Malawi, sub-Saharan Africa. African tick-bite fever: four cases among Swiss travelers returning from South Africa. Update: management of patients with suspected viral hemorrhagic fever—United States. Preheim Departments of Medicine, Medical Microbiology and Immunology, Creighton University School of Medicine, University of Nebraska College of Medicine, and V. The clinical manifestations vary widely from asymptomatic disease (up to 40% of patients) to fulminant liver failure. In the United States cirrhosis has an estimated prevalence of 360 per 100,000 population and accounts for approximately 30,000 deaths annually. The majority of cases in the United States are a result of alcoholic liver disease or chronic infection with hepatitis B or C viruses. A Danish death registry study (5) examined long-term survival and cause-specific mortality in 10,154 patients with cirrhosis between 1982 and 1993. The results revealed an increased risk of dying from respiratory infection (fivefold), from tuberculosis (15-fold) and other infectious diseases (22-fold) when compared to the general population. In a prospective study (6) 20% of cirrhotic patients admitted to the hospital developed an infection while hospitalized. The mortality among patients with infection was 20% compared with 4% mortality in those who remained uninfected. The most common bacterial infections seen in cirrhotic patients are urinary tract infections (12% to 29%), spontaneous bacterial peritonitis (7% to 23%), respiratory tract infections (6% to 10%), and primary bacteremia (4% to 11%) (7). The increased susceptibility to bacterial infections among cirrhotic patients is related to impaired hepatocyte and phagocytic cell function as well as the consequences of parenchymal destruction (portal hypertension, ascites, and gastroesophageal varices). It should be noted that the usual signs and symptoms of infection may be subtle or absent in individuals who have advanced liver disease. Thus a high index of suspicion is required to ensure that infections are not overlooked in this patient population, especially in those who are hospitalized. Occasionally fever may be due to cirrhosis itself (8), but this must be a diagnosis of exclusion made only when appropriate diagnostic tests, including cultures, have been unrevealing. The incidence of infection is highest for patients with the most severe liver disease (6,21–23). Accurate assessment for risk of infection is dependent upon proper classification of the extent of liver disease. The Child–Pugh scoring system of liver disease severity (24) is based upon five parameters: (i) serum bilirubin, (ii) serum albumin, (iii) prothrombin time, (iv) ascites, and (v) encephalopathy. A total score is 342 Preheim Table 1 Modified Child–Pugh Classification of Liver Disease Severity Points Assigned Parameter 1 2 3 Ascites None Slight Moderate/severe Encephalopathy None Grade 1–2 Grade 3–4 Bilirubin (mg/dL) <2. Patients with chronic liver disease are placed in one of three classes (A, B, or C). Despite having some limitations the modified Child–Pugh scoring system continues to be used by many clinicians to assess the risk of mortality in patients with cirrhosis (Table 1). Several mechanisms have been proposed to explain the movement of organisms from the intestinal lumen to the systemic circulation (reviewed in Ref. Cirrhosis-induced depression of the hepatic reticuloendothelial system impairs the liver’s filtering function, allowing bacteria to pass from the bowel lumen to the bloodstream via the portal vein. Cirrhosis also is associated with a relative increase in aerobic gram-negative bacilli in the jejunum. A decrease in mucosal blood flow due to acute hypovolemia or drug-induced splanchnic vasoconstriction may compromise the intestinal barrier to enteric flora, thereby increasing the risk of bacteremia. Finally, bacterial translocation may occur with movement of enteric organisms from the gut lumen through the mucosa to the intestinal lymphatics. From there bacteria can travel through the lymphatic system and enter the bloodstream via the thoracic duct. An elevated bilirubin level also is correlated with a high risk of peritonitis in patient with cirrhosis (28). Infections in Cirrhosis in Critical Care 343 Figure 1 Pathogenic mechanisms underlying spontaneous bacterial perito- nitis. Therefore a high index of suspicion must be maintained in all cases of cirrhotic patients who have ascites and are acutely ill. Gram-stain of centrifuged ascitic fluid will reveal organisms in approximately 30% of cases. Inoculating some fluid directly into blood culture bottles increases the yield of positive cultures. But this nonquantitative culture technique also increases the risk of false-positives if any skin flora contaminant is introduced into the blood culture bottle at the bedside. If ascitic fluid cultures yield polymicrobial flora, Candida albicans (or other yeast), or Bacteroides fragilis one should suspect a secondary peritonitis caused by an acute abdominal infection. Earlier detection and treatment and the use of non- nephrotoxic antibiotics has contributed to the increased short-term survival. However the risk of aminoglycoside nephrotoxicity in cirrhotic patients has limited the usefulness of this class of agents (30). Cefotaxime has been shown effective in a number of trials with regimens of 2 g administered every 8 hours for five days (26) or 2 g every 12 hours for a mean of nine days (31). These included intravenous followed by oral therapy with amoxicillin–clavulanic acid (36) or ciprofloxacin (37) and oral ofloxacin (38). While some experts recommend that patients with moderate symptoms and a positive response to a short course of intravenous antibiotics could benefit from therapy with oral fluoroquinolones (39), others have found the supporting evidence to be inconclusive (40). A major concern regarding repeated or prolonged courses of antibiotic prophylaxis is selection for resistant bacterial pathogens. The majority of these patients have asymptomatic bacteriuria, but approximately one-third have symptomatic infections (23).
The relationship between the therapeutic efficacy and particular acupoints further shows that the meridians are closely related to the neural segments buy cheap vytorin 30 mg online cholesterol saturation index definition. For instance vytorin 30 mg with visa poor cholesterol ratio, the points of the Heart Meridian of Hand-Shaoyin may be used to treat diseases of the heart cheap vytorin 20 mg with visa lowering cholesterol what foods to avoid, lung generic 30 mg vytorin overnight delivery cholesterol chart nz, and trachea. The same meridian passes through the medial aspect of the tip of the little finger, and the medial aspect of the forearm and the chest. The skin of these areas where the meridian passes is controlled by the first-third neural segments of the thoracic nerves. This indicates that these areas and the heart, lung, and trachea are under the domination of the same neural segments. Another example is the long branches of the intercostal nerve that descend for several segments. According to the orientation of the sensation of needling and the range of indications of the acupoints, there exists considerable coherency between the segmental nerve distribution of the acupoints and that of the organs. These nerve segments are also vegetal nerve segments that dominate the celiac and pelvic organs. The traits of the meridian may be related to its special morphological structure, which might explain the possibility of the treatment of the internal-organ diseases by puncturing or moxibusting the superficial acupoints. The relationship between the meridian-points and the peripheral nerves is different from that between the body trunk and limbs. On the body trunk, the nerves are segmental and arranged almost annularly, and occasionally, are vertical. This phenomenon may interpret the reason for the radiating nature of the needling sensation along the meridian path. Based on the overlapped and anastomosed relationship between the segments of the afferent nerve of the visceral organs and some special acupoints, we may at least partially explain the aspect of the morphologic basis of stimulating the acupoints to treat diseases of the visceral organs. Other experiments (Tao and Li 1993; Tao and Ren 1994) also validated the phenomena that afferent fibers of the body surface and the relative viscera converge at the same neuron. Using double-labeling technology, researchers (Tao and Ren 1995) found double-labeled cells at T2 5. These phenomena imply that the effect of acupuncture on the visceral function may occur at the lower center (spinal cord), and that the sensory impulse 70 2 Neuroanatomic Basis of Acupuncture Points of the acupoints or the peripheral nerves activated by acupuncture could affect the sensation and function of the viscus through the efferent branches of the axons. In addition, by using the methods of neural degeneration and lesion techniques, researchers also found that the nucleus of the brainstem, hypothalamus, and cortex play an important role in the relationship between the meridian-point and viscus. For structural feature of acupoint Rongquan (K-1), there were many receptors at side of muscular mantle and fiber, such as free nerve ending, muscular spindle, and so on. Collectively, the area of an acupoint is observed to contain free nerve ending, Vater-Pacini corpuscles, and muscle spindle. Furthermore, the acupoints and meridians are observed to be closely related to the peripheral nerves. These observations suggest that the sensory fibers of the somatic nerve serve as an afferent pathway of acupuncture. On the other hand, many studies show that the acupuncture could induce activation of the internal organs. In 1978, Toda and Ichioka reported that type Ċ afferent fibers were sufficient for acupuncture analgesia in rats. In addition, Pomeranz (1986) also found that type Ċ afferent fibers were adequate to produce acupuncture analgesia. Some researchers believed that the acupoint maps were essential for localizing the sites where the best De-Qi could be achieved (i. Lu (1983) showed that type Ċ and ċ afferent fibers were important for acupuncture analgesia in rabbits and cats because diluted procaine (0. In 1985, Wang et al carried out some observational experiments on human subjects using direct microelectrode recordings from single fibers in the median nerve, and performed acupuncture on the distal side. They observed that during De-Qi, numbness was related to the activation on type Ċ muscle afferent fibers; heaviness, distension, and aching were owing to the activation of type ċ fibers; and soreness was related to the activation of type Č non-myelinated fibers. The acupuncturists also noticed that when the patient got the De-Qi sensation, the muscle grabbed the needle. Although there is still disagreement on the relationships between the afferent effect of the acupuncture and the fiber type of the somatic nerves (Zhu 1998), anatomical and electrophysiological evidence lead us to the conclusion that afferent fibers of type Ċ and ċ are responsible for transmitting the acupuncture signal. However, there is also evidence showing that all typeĉ, Ċ, ċ, and Č fibers may participate in the signal transmission of acupuncture. Some studies showed that electroacupuncture mainly stimulate the fibers of type Ċ and ċ fibers, while acupuncture manipulation mainly stimulate the fibers of type ċ and Č, producing feeling of sourness, numbness, distention, and weightiness. Previous studies on this issue showed, for example, that the effect of acupuncture was eliminated by the dissection of dorsal funiculus of the spinal cord, and that acupuncture analgesia and adjustment of visceral function were eliminated by the dissection or destruction of the lateral funiculus of the bilateral ventral spinal cord. In patients with syringomyelia, owing to the destruction of concatenation of conduction tract of thermic sense and the ventral lateral funiculus, both the effect and sensation of the acupuncture disappeared. Acupuncture signals entering the posterior horn of the spinal cord were also observed to influence the neurons of the anterior and lateral horns to initiate soma-viscus reflex or soma-soma reflex, thus, adjusting the pain reaction and activation of viscus through sympathetic fibers or Ȗ-efferent fibers. All these facts demonstrate that acupuncture signals affect the neurons of the posterior horn after entering the spinal cord, and then transmit upward through the ventral lateral funiculus. Through transmission from the spinal cord, the signals enter the brain, and are exchanged in the thalamus, and then projected upward to the cerebral cortex, to produce the sensation of acupuncture. If the connection between the cortex and axons of the sensory neuron of the thalamus is interrupted, then the patients may not be able to ascertain the location of the sensation of acupuncture. However, none has been supported by convincing evidence, except for the data from neurobiological research. Substantial data have shown that meridians and acupoints are closely associated with the peripheral nerves. Furthermore, the nerves distributed at the acupoints and their correlative organs have been observed to belong to the same spinal segment, or within the range of the nerve segments belonging to the correlative organs. With respect to the nerves, the acupoints have been observed to differ not only in the density of the nerve distribution and thickness of the nerve fibers under every acupoint, but also in the shape of the nerve endings. Owing to these differences, the puncturing methods and puncturing deepness vary from one acupoint to another. Accordingly, the reflection of De-Qi is also observed to be different, depending on the acupoints 73 Acupuncture Therapy of Neurological Diseases: A Neurobiological View punctured. The effect of a given acupoint on the body is observed to be at least partly related to the structural traits and its location. However, there are also some unresolved issues in the neuroanatomic studies regarding the relationship between the nerves and meridians (Sun et al. For example, there has been no consistency, to some extent, between the segments of some organs and those of the distribution of acupoints that are effective for the organs (e. Another example is the meridians on the head, such as Gallbladder Meridian of Foot-Shaoyang and Sanjiao Meridian of Hand-Shaoyang. Therefore, before we try to fully understand the mystery of acupoints and meridians, it may be valuable to retain the meridian theory in mind for efficient clinical practice and laboratory research. It is possible that there are issues that we cannot understand with our present knowledge. Hence, if we dismiss this ancient theory, we may lose some important information about the nature of acupuncture and guideline for the clinical practice. Note: Most contents of Section 3 in this chapter (The neuroanatomic basis of acupoints) have been written based on the original studies by Drs. The original article was informally and partially published in Chinese in 1959, 1960 and 1973. Science 128: 712 715 Campbell A (2006) Point specificity of acupuncture in the light of recent clinical and imaging studies.
This is further promoted if farmers can market their products directly to consumers trusted vytorin 20 mg cholesterol medication and viagra, and thereby receive a greater proportion of final price discount 20mg vytorin with visa heart healthy cholesterol lowering foods. This model of food production can yield potent health benefits to both producers and consumers purchase vytorin 30 mg online cholesterol elevated, and simultaneously reduce environmental pressures on water and land resources cheap vytorin 20 mg without a prescription cholesterol lowering diet heart foundation. Agricultural policies in several countries often respond primarily to short-term commercial farming concerns rather than be guided by health 140 and environmental considerations. For example, farm subsidies for beef and dairy production had good justification in the past --- they provided improved access to high quality proteins but today contribute to human consumption patterns that may aggravate the burden of nutrition related chronic disease. This apparent disregard for the health consequences and environmental sustainability of present agricultural production, limits the potential for change in agricultural policies and food production, and at some point may lead to a conflict between meeting population nutrient intake goals and sustaining the demand for beef associated with the existing patterns of consumption. For example, if we project the consumption of beef in industrialized countries to the population of developing countries, the supply of grains for human consumption may be limited, specially for low-income groups. Changes in agricultural policies which give producers an opportunity to adapt to new demands, increase awareness and empower communites to better address health and environmental consequences of present consumption patterns will be needed in the future. Integrated strategies aimed at increasing the responsiveness of governments to health and environmental concerns of the community will also be required. The question of how the world’s food supply can be managed so as to sustain the demands made by population-size adjustments in diet is a topic for continued dialogue by multiple stake-holders that has major con- sequences for agricultural and environmental policies, as well as for world food trade. Physical activity A large proportion of the world’s population currently takes an inadequate amount of physical activity to sustain physical and mental health. The heavy reliance on the motor car and other forms of labour- saving machinery has had much to do with this. Cities throughout the world have dedicated space for motor cars but little space for recreation. Changes in the nature of employment have meant that more time is spent travelling to and from work, thereby limiting the time available for the purchase and preparation of food. Cars are also contributors to growing urban problems, such as traffic congestion and air pollution. Urban and workplace planners need to be more aware of the potential consequences of the progressive decline in occupational energy expenditure, and should be encouraged to develop transport and recreation policies that promote, support and protect physical activity. For example, urban planning, transportation and building design should give priority to the safety and transit of pedestrians and safe bicycle use. Global marketing, in particular, has wide-ranging effects on both consumer appetite for goods and perceptions of their value. While some traditional diets could benefit from thoughtful modification, research has shown that many are protective of health, and clearly environmentally sustainable. They must be based on scientific evidence on the ways in which people’s dietary and physical activity patterns have positive or adverse effects on health. In practice, strategies are likely to include at least some of the following practical actions. The data required for implementing effective policies need to be specific for age, sex and social group, and indicate changing trends over time. The ultimate goal of information and communication strategies is to assure availability and choice of better quality food, access to physical activity and a better- informed global community. Its work in the area of nutrition and labelling could be further strengthened to cover diet-related aspects of health. Governments could make it easier for consumers to exercise healthier choices, in accordance with the population nutrient intake goals given in this report by, for example, promoting the wider availability of food which is less processed and low in trans fatty acids, encouraging the use of vegetable oil for domestic consumers, and ensuring an adequate and sustainable supply of fish, fruits, vegetables and nuts in domestic markets. For example, consumers should be able to ascertain not only the amount of fat or oil in the meals they have chosen, but also whether they are high in saturated fat or trans fatty acids. They should involve alliances that encourage the effective implementation of national and local strategies for healthy diets and physical activity. Intersectoral initiatives should encourage the adequate production and domestic supply of fruits, vegetables and wholegrain cereals, at affordable prices to all segments of the population, opportunities for all to access them regularly, and individuals to undertake appropriate levels of physical activity. The social, economic, cultural and psychological determinants of dietary and physical activity choice should be included as integral elements of public health action. There is an urgent need to develop and strengthen existing training programmes to implement these actions successfully. These chronic diseases remain the main causes of premature death and disability in industrialized countries and in most developing countries. Developing countries are demonstrably increasingly at risk, as are the poorer populations of industrialized countries. In communities, districts and countries where widespread, integrated interventions have been implemented, dramatic decreases in risk factors have occurred. Successes have come about where the public has acknowledged that the unnecessary premature deaths that occur in their community are largely preventable and have empowered them- selves and their civic representatives to create health-supporting environments. This has been achieved most successfully by establishing a working relationship between communities and governments; through enabling legislation and local initiatives affecting schools and the workplace; by involving consumers’ associations; and by involving food producers and the food-processing industry. There is a need for data on current and changing trends in food consumption in developing countries, including research on what influences people’s eating behaviour and physical activity and what can be done to address this. There is also a need, on a continuing basis, to develop strategies to change people’s behaviour towards adopting healthy diets and lifestyles, including research on the supply and demand side related to this changing consumer behaviour. Beyond the rhetoric, this epidemic can be halted --- the demand for action must come from those affected. Acknowledgements Special acknowledgement was made by the Consultation to the following individuals who were instrumental in the preparation and proceedings of the meeting: Dr C. Uauy, London School of Hygiene and Tropical Medicine, London, England and Institute of Nutrition of the University of Chile, Santiago, Chile. The Consultation also thanked the authors of the background papers for the Consultation: Dr N. Prentice, Medical Research Council Human Nutrition Research, Cambridge, England; Professor K. The Consultation also recognized the valuable contributions made by the following individuals who provided comments on the background documents: Dr Franca Bianchini, Unit of Chemoprevention, International Agency for Research on Cancer, Lyon, France; Mr G. Ferro-Luzzi, National Institute for Food and Nutrition Research, Rome, Italy; Dr R. Francis, Freeman Hospital, Newcastle-upon-Tyne, England; Dr Ghafoor- unissa, Indian Council of Medical Research, New Delhi, India; Dr K. McMichael, Australian National University, Canberra, Australian Capital Territory, Australia; Professor S. O’Dea, Menzies School of Health Research, Alice Springs, Northern Territory, Australia; Professor D. Walker, South African Institute for Medical Research, Johannesburg, South Africa; Dr S. Acknowledgement was made by the Consultation to the following individuals for their continualguidance:DrD. Robertson for her valuable contribution to the preparation and running of the meeting, to Mrs A. This manual has been written with the aim of developing the knowledge, skills and attitudes of nurses and midwives regarding infections and infectious diseases and their prevention and control. A workbook is provided separately, with opportunities for self-assessment through learning activities. A completed workbook is also available for each module to give further guidance to readers. The document may nevertheless be freely reviewed, abstracted, reproduced or translated into any other language (but not for sale or for use in conjunction with commercial purposes) provided that full acknowledgement is given to the source. Any translation should include the words: The translator of this document is responsible for the accuracy of the translation.
Symptoms include shortness of breath purchase 20mg vytorin with mastercard cholesterol your body makes, chest pain purchase vytorin 20 mg free shipping cholesterol x?u trong mau, dizziness generic vytorin 20 mg mastercard blood cholesterol chart uk, or syncope with exercise buy vytorin 30 mg with amex cholesterol ziola. Family history of heart disease or sudden death prior to age 40 should raise index of suspicion. In 25% of patients, there is dynamic left ventricular mid cavity obstruction that results in a systolic ejec- tion murmur that increases in intensity in the standing position. On exam, there may be increased jugular venous pressure, pulmonary rales, hepatomegaly, and possibly peripheral edema. Cardiac auscultation may reveal an S3–4 summation gallop, best heard with the bell at the left lower sternal border or apex. Myocarditis Myocarditis should be suspected in any child with signs of heart failure who was previous well, especially with a preceding history of a viral illness. On cardiac exam there is often unexplained tachycardia and the heart sounds are usually muffled. The presence of ventricular arrhythmias indicates fulminant presentation and should prompt immediate transfer to the intensive care unit for potential cardiopulmonary support. Mehrotra • Many newborn children appear to have cardiomegaly when in fact the thymus is contributing to the “cardio-thymic shadow” giving the appearance of an enlarged heart. This can also be seen in many cyanotic heart diseases where there is excessive pulmonary blood flow An enlarged heart with no evidence of increase in pulmonary vascular markings suggests an obstructive lesion Chapter 2 Cardiac Interpretation of Pediatric Chest X-Ray Ra-id Abdulla and Douglas M. Luxenberg Key Facts • The cardiac silhouette occupies 50–55% of the chest width on an anterior–posterior chest X-ray • When assessing the cardiovascular system on a chest X-ray, the following must be noted: – The size of the heart (small, normal, or large) – The contours of the heart reflecting various cardiovascular components which can be enlarged, absent, or displaced – The Pulmonary vascularity which can be diminished, normal, or increased • Many newborn children appear to have cardiomegaly when in fact the thymus is contributing to the “cardio-thymic shadow”. Introduction Chest X-ray is an important tool in evaluating heart disease in children. Luxenberg diagnostic procedures is significant making their routine use difficult. Chest X-ray on the other hand is easy to perform, economical, and provides important informa- tion including heart size, pulmonary blood flow, and any associated lung disease. History of present illness coupled with physical examination provides the treating physician with a reasonable list of differential diagnoses which can be further focused with the aid of chest X-ray and electrocardiography making it possible to select a management plan or make a decision to refer the child for further evalua- tion and treatment by a specialist. Approach to Chest X-Ray Interpretation Unlike echocardiography, chest X-ray does not provide details of intracardiac structures. Instead the heart appears as a silhouette of overlapping cardiovascular chambers and vessels. The size and shape of the heart as well as the pulmonary vascular markings, pleura and parenchymal lung markings provide helpful information regarding the heart/lung pathology. It is easy to be overwhelmed with a prominent pathology on a chest X-ray thus overlooking more subtle changes; therefore, it is imperative to conduct interpretation of chest X-ray carefully and systematically considering the fol- lowing issues. Heart size: The size of the heart represents all that lies within the pericardial sac. This includes the volume within each cardiac chamber, cardiac wall thickness, pericardial space, and any other additional structure such as mass from a tumor or air trapped within the pericardium (pneumopericardium). Therefore, enlargement of any of these structures will lead to the appearance of cardiomegaly on chest X-ray. Dilated atria or ventricles such as that seen in heart failure will cause the cardiac silhouette to appear large, as would hypertrophy of the ventricular walls or fluid accumulation within the pericardial space (Tables 2. Heart shape: The presence of certain subtleties in the cardiac shape may point to a particular pathology and thus help narrow the differential diagnosis. Enlargement or hypoplasia of a particular component of the heart will alter the normal shape of the cardiac silhouette. Therefore, each aspect of the heart border should be examined to assess for abnormalities. On the other hand, pulmonary atresia will cause the mediastinum to be narrow due to hypoplasia of the pulmonary artery. Pulmonary blood flow: Pulmonary vasculature is normally visible in the hilar region of each lung adjacent to the borders of the cardiac silhouette. An increase in pulmonary blood flow or congestion of the pulmonary veins will cause prominence of the pulmonary blood vessels. A significant increase in pulmonary blood flow 2 Cardiac Interpretation of Pediatric Chest X-Ray 19 Table 2. Pleural space: Heart failure results in venous congestion which may lead to fluid accumulation within the pleural spaces manifesting as a pleural effusion. Pleural effusion may be noted on chest X-ray as a rim of fluid in the outer lung boundaries of the chest cavity or as haziness of the entire lung field in a recumbent patient due to layering of the fluid behind the lungs. The right border of the cardiac silhouette consists of the following structures from top to bottom: superior vena cava, ascending aorta, right atrial appendage, and right atrium (Fig. The left border of the cardiac silhouette is formed from top to bottom by the aortic arch (aortic knob), pulmonary trunk, left atrial appendage, and the left ventricle. In the normal chest X-ray only the larger, more proximal pulmonary arteries can be visualized in the hilar regions of the lungs and the lung parenchyma should be clear with no evidence of pleural effusion (Fig. Lateral View The cardiac silhouette in this view is oval in shape and occupies the anterior half of the thoracic cage. On the left side, the heart border is formed from top to bottom by the aortic arch (knob), main pulmonary artery, left atrial appendage, and the left ventricle. A normal pulmonary blood flow pattern is present with no evidence of pleural disease 22 Ra-id Abdulla and D. The right ventricle is the anterior most part of the heart and occupies the middle region within the cardiac silhouette. The main pulmonary artery is to the left of the ascending aorta and forms a small portion of the middle of the left car- diac silhouette border as it courses posteriorly and bifurcates into right and left pulmonary arteries. The various cardiovascular components cannot be visualized by chest X-ray, however, knowledge of cardiac and vascular anatomy within the cardiac silhouette is helpful in understanding both normal and abnormal findings on chest X-ray (Fig. Change in the shape of the cardiac silhouette may point to specific cardiac structural abnormalities; for example, an uplifted cardiac apex points to right ventricular hypertrophy due to displacement of the left ventricular apex upward and laterally. We will now discuss some specific congenital cardiac lesions and their associated chest X-ray findings. An atrial septal defect causes an increase in heart size with fullness of the right heart border due to right atrial enlargement. The pulmonary arteries are full and may be well visualized even in the peripheral lung fields indicating an increase in pulmonary blood flow. In severe cases, the right ventricle is dilated and is noted as fullness of the anterior most aspect of the cardiac silhouette causing obliteration of the usual space between the heart and sternum. The increase in pulmonary blood flow will manifest as engorged pulmonary vasculature. The increase in return of blood to the left atrium and ventricle may cause left atrial and left ventricular dilation (Fig. An increase in pulmonary blood flow results in prominent pulmonary vasculature which may be noted in the peripheral lung fields. The left atrium and ventricle become dilated due to increased 2 Cardiac Interpretation of Pediatric Chest X-Ray 25 Fig. The resultant significant increase in pulmonary blood flow results in prominent pulmo- nary vasculature. This, coupled with regurgitation of the atrioventricular valve, results in cardiomegaly due to dilation of all cardiac chambers. The heart is enlarged due to dilation of all cardiac cham- bers from to left to right shunting and atrioventricular valve regurgitation. This patient also has right upper lobe atelectasis which may be seen in patients with a significant increase in pulmonary blood flow and heart failure. This manifests as prominence of the pulmonary artery 2 Cardiac Interpretation of Pediatric Chest X-Ray 27 Fig.