A variety of cardiac, pulmonary, and esophageal lesions can result in chest pain. Pericarditis causes severe substernal chest pain that is exacerbated by movement or respiration. Patients sometimes report that the pain diminishes when assuming an upright position and leaning forward. Tachyarrhythmias can compromise myocardial blood flow and result in ischemic pain, often in association with lightheadedness, syncope, or palpitations. The pain associated with aortic dissection varies according to the site of the lesion. Dissection in the ascending aorta causes anterior chest pain. Dissection in the upper portion of the arch or descending aorta causes pain that radiates to the back.

Pulmonary conditions are important considerations in the differential diagnosis of chest pain in children. Spontaneous pneumothorax causes acute onset of unilateral chest pain. The pain is often difficult to localize and may be accompanied by dyspnea. Pain caused by pleural irritation (pleuritic pain) is typically exacerbated during inspiration; physical examination may demonstrate a pleural rub. Pleural irritation can occur as a result of a viral infection or as a complication of bacterial pneumonia. Chest pain is part of the constellation of symptoms in many children with pneumonia. The acute onset of chest pain in a child with sickle cell disease is an important clinical indicator of acute chest syndrome. Chest pain in children with pulmonary embolism may be accompanied by cough, dyspnea, or hemoptysis, and sometimes includes a pleuritic component.

Esophageal pathology can produce symptoms localized to the thorax. The pain associated with esophagitis tends to be localized to the retrosternal region and has a burning character. Because gastroesophageal reflux is the usual underlying cause, assuming the supine position may worsen the pain. An esophageal foreign body may cause substantial retrosternal pain.

Chest pain in children without a known underlying cardiac or pulmonary abnormality is usually musculoskeletal in origin; for example, rib fracture, muscle strain, contusion, or costochondritis. Pain in these patients is usually less severe than pain associated with substantial intrathoracic pathology. The chest wall pain may be localized and non-radiating, and is often exacerbated by exercise or palpation.¹

Costochondritis is an inflammatory process of one or more of the costochondral cartilages that causes localized tenderness and pain of the anterior chest wall at the costochondral and/or costosternal articulations. Most cases in children are idiopathic. Others are a result of trauma, exercise, or irritation because of forceful coughing. Some patients have an underlying systemic condition, such as an autoimmune disorder, chronic renal failure, or thyroid disease. In most patients, there is no appreciable soft-tissue swelling on physical examination. Diagnostic imaging studies are often normal. CT sometimes shows cartilaginous irregularity/enlargement, local soft-tissue swelling, and resorption of adjacent bone. Signal alteration in the inflamed cartilage is sometimes visible on MRI. The pain tends to be unilateral, and most frequently is localized in the region of the fourth through sixth costochondral junctions. The onset of pain is insidious for most patients.^2,3

Tietze syndrome refers to unilateral pain and swelling of the anterior chest wall in the region of the second and third costochondral junctions, with normal overlying skin. This is an idiopathic condition that often follows an intermittent course for several months. Radiographs are normal. Potential MRI findings include enlargement and thickening of cartilage at the symptomatic site, increased signal intensities of affected cartilage on T2-weighted and short tau inversion recovery (STIR) images, and bone marrow edema in the adjacent subchondral bone.⁴

Precordial catch (Texidor twinge) is a clinical syndrome characterized by the sudden onset of severe or shooting chest pain that is usually localized over the cardiac apex and lasts for no more than a few minutes. The pain is worsened by deep inspiration. The symptoms are recurrent. This is a common cause of chest pain in children and adolescents. The etiology of this syndrome is unknown. Radiographic studies are normal.⁵

Slipping rib syndrome results from inadequate or damaged medial fibrous attachments of the anterior margins of the eighth, ninth, or tenth ribs that allow a cartilage tip to slip superiorly and impinge on the intervening intercostal nerve. Slippage of the rib is associated with sudden onset of pain, and tenderness at the site may persist for a few days. Moving the ribs at physical examination reproduces the pain. The diagnosis can be confirmed with real-time sonographic evaluation of the costal cartilage during provocative maneuvers.^6–8

Sternal Anomalies

Normal Development

The sternum develops from 2 longitudinal bands of mesoblastic tissue that are separate from the ribs. These bands eventually fuse. The developing ribs migrate medially and fuse with the sternal tissue. Cartilaginous centers form within this mesoblastic tissue. The manubrium (and in many individuals, the first sternal segment) have single cartilaginous centers; there are paired centers for the other sternal segments. The earliest sonographic visualization of the fetal sternum with two to three ossification centers is at 19 weeks’ gestational age. The fifth ossification center is first visible at 29 weeks’ gestation.

Ossification is usually radiographically visible in the manubrium and sternal body at birth. Xiphoid ossification occurs during the first year of life. Fusion of the paired ossification centers in the body progresses in a superior-to-inferior pattern, and is usually complete by 1 to 2 years of age. Fusion between these segments progresses during childhood in an inferior-to-superior pattern. The manubrium, sternal body, and the xiphoid ossification centers usually remain separate throughout childhood. The pattern of sternal ossification center development and fusion varies considerably between individuals.⁹

Pectus Excavatum

Pectus excavatum is a congenital anomaly in which there is inward depression of the sternum and deformities of the adjacent ribs. The pattern and severity of sternal and rib deformities vary greatly between patients. In some patients, the entire sternum, including the manubrium, is depressed; in other patients, the deformity is confined to the inferior aspect of the sternum. Rotational deformity of the sternum (sternal torsion), usually to the right, often accompanies pectus excavatum. In some patients with sternal rotation, the associated rib deformities are asymmetric (Figure 8-1).^10,11

Most patients with pectus excavatum are asymptomatic, aside from the cosmetic deformity. Severe deformity, however, can result in cardiorespiratory symptoms. Pectus excavatum is more common in males. The frequency of this condition in the general population is approximately 1%, although most patients have only mild sternal deformity. Pectus excavatum can occur in association with idiopathic scoliosis, Marfan syndrome, homocystinuria, neurofibromatosis type 1 (50% of patients), osteogenesis imperfecta, Turner syndrome, Ehlers-Danlos syndrome, and myotonic muscular dystrophy (Figure 8-2).

Frontal chest radiographs of children with pectus excavatum show steep inferior sloping of the anterior aspects of the ribs as a consequence of the sternal deformity. With moderate to severe pectus excavatum, there is alteration in the appearance of the heart on frontal chest radiographs that can lead to a mistaken diagnosis of cardiac or pulmonary pathology. The sternal deformity causes the heart to shift to the left and rotate on its vertical axis, resulting in a straight left-heart border and the appearance of mild cardiomegaly. The right-heart border is obscured by the depressed sternum and there is often increased density along the right-heart border; this can mimic the appearance of atelectasis or consolidation in the right middle lobe (Figure 8-3). The lateral radiograph is diagnostic: the depressed sternum projects posterior to the anterior rib margins (Figure 8-4). There are rare patients who develop air trapping in the left lung because of bronchomalacia of the left main bronchus in association with pectus excavatum.

CT evaluation accurately assesses the severity of pectus excavatum and determines the effects on intrathoracic structures. Three-dimensional CT images are sometimes useful for planning of surgical repair (Figure 8-5). The Haller index quantifies the severity of pectus excavatum. This is the ratio of the transverse diameter of the thoracic cavity to the distance between the sternum and spinal column measured on an axial image at the level of most severe deformity (Figure 8-6). In normal patients, the mean Haller index is 2.56 (0.35 standard deviation [SD]). An index of greater than 3.25 indicates moderate to severe pectus deformity.¹²

The traditional surgical method for pectus excavatum repair was first described by Ravitch. This consists of resection of deformed cartilages and correction of the sternal angulation by a wedge osteotomy in the upper sternal cortex. Various modifications of this technique have been developed over time. The most commonly utilized technique for the treatment of moderate to severe pectus excavatum in current practice is the insertion of a curved metal bar (Nuss bar) dorsal to the sternum. Stabilizer bars are positioned along the outer margins of the retrosternal bar. The bar is usually removed after about 2 years. Preoperative CT allows measurements for accurate Nuss bar sizing. Common radiographic findings in the perioperative period include pleural fluid accumulation, pneumothorax, pneumomediastinum, and atelectasis. Potential long-term complications include bar migration and separation from a stabilizer bar. Reactive changes in the ribs adjacent to the stabilizer bars are normal.^13–16

Pectus Carinatum

Pectus carinatum (pigeon breast) is an idiopathic congenital deformity in which there is abnormal anterior protrusion of the sternum. The deformity is typically confined to the inferior third of the sternum. Pectus carinatum is approximately 10 times less common than pectus excavatum. The male-to-female ratio is 4:1. In approximately half of patients with pectus carinatum, there is an association with congenital heart disease (often cyanotic). Syndromes associated with pectus carinatum include Marfan syndrome, homocystinuria, spondyloepiphyseal dysplasia, prune-belly syndrome, Morquio syndrome, osteogenesis imperfecta, and Noonan syndrome.^17,18

Lateral chest radiographs of children with pectus carinatum show protrusion of a portion of the sternum anterior to the anterior rib ends (Figure 8-7). This most often involves the inferior third of the sternum (Figure 8-8). In some patients, there is posterior angulation of the xiphoid process. The costal cartilages adjacent to the sternal anomaly are deformed. The type of pectus carinatum in which there is symmetric protrusion of the body of the sternum and costal cartilages is sometimes termed chondrogladiolar protuberance or keel chest deformity. A less-common type of pectus carinatum consists of protrusion of the manubrium. There is also a mixed type of pectus carinatum in which there is rotation of the sternum, with depression of the costal cartilages and sternum on one side, and protrusion of these structures on the contralateral side. CT imaging is useful for selected patients to plan operative intervention or monitor the deformity during conservative therapy. The Haller index serves to quantify the severity of the deformity.¹⁹