Relation of right ventricular morphology and function in pectus excavatum to the severity of the chest wall deformity

Abstract

Although pectus excavatum (PE) is thought to impair right ventricular (RV) performance, the degree of RV dysfunction, if any, produced by this chest wall deformity remains controversial. To address this issue, we performed 2-dimensional echocardiography and chest wall radiography in 28 subjects with mild-to-severe degrees of PE to assess RV morphology and function in relation to the degree of the chest wall deformity. Measurements of RV anatomy and function obtained in these patients were compared to those of 24 normal control subjects of similar age and sex. In subjects with PE, mean RV outflow tract diameter at the aortic root level was narrower (1.4 ± 0.3 cm/m 2) and end-diastolic (10 ± 2.3 cm 2/m 2) and end-systolic (5.8 ± 1.4 cm 2/m 2) areas were larger than those in normal controls (1.6 ± 0.3, 8.6 ± 1.7, and 4.5 ± 1.2 cm 2/m 2, respectively; p < 0.013). The magnitude of these abnormalities was related to the degree of the chest wall deformity evaluated on the chest radiogram (r = 0.54, 0.51, and 0.49, respectively). RV planar emptying fraction, an index of RV systolic function, was reduced in subjects with PE (42 ± 10%) compared to the normal controls (48 ± 10%; p = 0.047). No relation could be found, however, between this index and the severity of the chest wall deformity. In addition, unusual morphologic features of the right ventricle previously reported as being suggestive of the presence of RV dysplasia, such as a rounded RV apex, sacculations of the RV free wall, and hypertrophy of the moderator band, were significantly more common in patients with PE (20 of 28 [71%]) than in the normal controls (3 of 24 [13%]; p < 0.001). Our results indicate that in patients with PE, moderate-to-severe degrees of chest wall deformity were associated with alterations in RV morphology and function. Furthermore, PE must be taken into account when 2-dimensional echocardiography is used as a screening tool to recognize RV morphologic abnormalities suggestive of RV dysplasia in asymptomatic patients.