Acquired valvular heart disease is caused by rheumatic heart disease, ³¹ arteriosclerosis, ⁹ hypertension, or congenital heart defects. The mitral and aortic valves usually are involved.

Chest radiographs of patients with valvular heart disease typically demonstrate changes in the size of the cardiac shadow, alterations in the size and configuration of specific heart chambers, and alterations in pulmonary vascularity (Figs. 23-1 and 23-2). Valvular calcification also may be present, suggesting mitral and aortic stenosis of the involved value. Specific radiographic findings are listed in Table 23-1. Magnetic resonance imaging (MRI) may be helpful in providing anatomic and functional information about patients with valvular heart disease. ^8,17

The diagnosis of valvular heart disease is made based on the patient’s clinical history, a physical examination, electrocardiography, chest radiography, and echocardiography. ⁴⁵ In the past, acquired valvular disease most often was caused by rheumatic fever. This is still the case in underdeveloped countries, but other causes predominate today in developed countries.

Aneurysms are circumscribed dilations of an arterial wall. Saccular aneurysms involve part of the circumference of the vessel, whereas fusiform aneurysms involve the entire circumference. If all three arterial layers (the tunica intima, media, and adventitia) are affected, the aneurysm is called a true aneurysm. False aneurysms disrupt arterial walls but are contained by the surrounding connective tissue. A number of conditions, including atherosclerosis, syphilis, mycoses, posttraumatic conditions, congenital conditions, cystic media necrosis, and arteritis, have been named as possible causes of aneurysms (Table 23-2; FIG. 23-3FIG. 23-4FIG. 23-5FIG. 23-6 and FIG. 23-7). Atherosclerosis is the most common cause and usually involves the descending aorta.

Aortic dissection occurs when a hematoma in the middle to outer third of the aortic wall longitudinally separates the aortic wall proximally and distally. Hematomas often develop as a result of a vasa vasorum hemorrhage, which is seen in patients with hypertension. The tunica intima may rupture and reconnect the hematoma with its aortic lumen, creating a “double barrel” aorta. A number of classification schemes have been developed to describe the nature and region of aortic involvement (e.g., DeBakey, Stanford).

The radiographic features of an aneurysm are limited to contour changes in the frontal and lateral projections. Although it does not indicate the presence of an aneurysm, vessel calcification provides a means of visualizing distortions of the vessel’s wall. Aortic dissection is suggested by mediastinal widening, cardiomegaly, pleural effusion, and (in rare cases) medial displacement of the calcified plaque more than 1 cm inward from the outer vessel wall of the descending aorta (which is called the calcification sign). ^10,11 MRI and computed tomography (CT) provide the best initial and follow-up evaluations of the aorta. ^27,56 Angiography may be used preoperatively to better define the vessel.

The clinical presentation of an aneurysm depends on its size and location; the majority are asymptomatic. ⁴¹ Compression of the vena cava (vena cava syndrome), stridor, hoarseness (caused by laryngeal nerve compression), dysphagia, and sternal chest pain may develop in patients who have a large aneurysm mass.

The risk of rupture is related to the size of the aneurysm. Aneurysms of the aortic arch or descending aorta that have a diameter of less than 5 cm rarely rupture. Those exceeding 6 cm have a significant risk of rupturing; 40% of those greater than 10 cm rupture. A patient with a rapidly expanding aneurysm of any size has a poor prognosis. ⁴¹

Juxtaductal, or adult type, coarctation of the aorta is a discrete narrowing of the aortic isthmus (the region between the arch and descending aorta) distal to the origin of the left subclavian artery and near the ductus or ligamentum arteriosus. ⁴⁶ Tubular hypoplasia, or infantile-type coarctation of the aorta, is less common and involves narrowing of a segment of the transverse aortic arch. Coarctation is more common in males and often develops in conjunction with other cardiovascular defects, particularly when it is found in infants.

Although the aorta is narrowed, the collateral circulation typically prevents hypoperfusion of the trunk and lower extremities. In one such collateral path, blood from the subclavian arteries (before the coarctation has developed) enters the internal mammary arteries. It flows to the anterior intercostals and across the intercostal anastomoses, reversing the normal blood flow of the posterior intercostals and causing it to enter the aorta distal to the coarctation that developed. The hypertrophy of the intercostal arteries causes characteristic inferior rib notching.

Pseudocoarctation is kinking of the aorta that commonly is seen secondary to arteriosclerosis in elderly patients.

Imaging features of infants with coarctation of the aorta may include cardiomegaly and possibly increased pulmonary vascular markings. In children and adults a characteristic inward deformity of the proximal descending aorta may be present with bulging of the vessel immediately above and below (the “figure 3” sign). This sign is seen uncommonly on images of infants because the aortic arch is difficult to observe. Although not pathognomonic for coarctation, bilateral inferior rib notching is common at the posterior angles of the third through ninth ribs (Fig. 23-8). Rib notching is not seen in the infant. MRI is the modality of choice for further assessment.

Most symptomatic infants with coarctation of the aorta have concurrent cardiovascular abnormalities (e.g., aortic stenosis, patent ductus arteriosus, ventricular septal defect). ⁴² Associated cardiac anomalies are uncommon in adults. A blood pressure difference of 20 mm Hg between the arms and legs is strongly indicative of coarctation. ^33,42 Treatment involves surgical correction of the deformity. ²⁵

Congenital heart disease (Table 23-3) encompasses a wide variety of defects that appear at birth as either isolated anomalies or part of larger complexes. Patients with congenital heart disease are categorized based on the presence or absence of cyanosis. Further subdivisions can be made based on the heart size and pulmonary vascularity.

Plain film radiography is used to evaluate pulmonary vascularity, heart size, and configuration of the great vessels (Fig. 23-9). ^15,50 Echocardiography, angiocardiography, and MRI are all useful imaging modalities for evaluating congenital heart defects. ^13,55

Although congenital heart disease can be so severe that an affected unborn fetus cannot survive, also it can be largely asymptomatic. Many infants with the condition seem to be healthy immediately after birth, but their condition changes as the ductus arteriosus closes and adult circulation begins. Some congenital heart diseases may not appear until adulthood (e.g., floppy mitral valve syndrome).