Dextrocardia with sinus solitus

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Figure. Routine chest radiograph of an asymptomatic 17-year-old girl.

A routine physical examination of this apparently well teenage girl revealed a right-sided cardiac apex. Chest radiography confirmed that her heart was in the right chest and that the cardiac apex pointed to the right. The aortic arch was on her left; mediastinal contours were normal; her lungs were clear; and the gastric bubble was on her left side.

Dextrocardia refers to a heart positioned in the right side of the chest. Situs solitus describes viscera that are in the normal position, with the stomach on the left side; in situs inversus, the positions of the abdominal organs and viscera are reversed. Dextrocardia with situs solitus occurs in an estimated 7500–29 000 living people worldwide. Dextrocardia should be distinguished from dextroposition, in which the heart is located within the right thorax but its apex points to the patient's left. Cardiac dextroposition can result from hypoplasia of the right lung or from a left-diaphragmatic hernia or eventration.

Patients with dextrocardia should undergo radiography of the chest and abdomen, electrocardiography and echocardiography. Other tests should be done when clinically indicated; for example, if Kartagener syndrome is suspected, radiography or CT of the paranasal sinuses might be necessary (bronchiectasis is best detected by CT scanning). Dextrocardia with situs solitus is often complicated by cardiovascular abnormalities, notably atrioventricular discordance, single ventricle, atrial or ventricular septal defect, anomalous pulmonary venous return or transposition of the great arteries. Although dextrocardia with situs inversus is seldom associated with congenital heart disease, these patients are at increased risk of pulmonary disease. Some 20% of patients with dextrocardia with situs inversus display Kartagener's syndrome, which includes chronic sinusitis, nasal polyposis and bronchiectasis.

Syndromes specifically associated with dextrocardia include scimitar syndrome, which includes hypoplasia of and anomalous arterial blood supply to the right lung along with anomalous venous connection of the right pulmonary veins to the inferior vena cava, and Cantrell's syndrome, which is characterized by a diverticulum of the ventricle and defects of the midline abdominal wall, anterior diaphragm, lower sternum and the diaphragmatic portion of the pericardium. About 30% of patients with asplenia or polysplenia have dextrocardia.