Cardiac performance in children with pectus excavatum

Clinical Evaluation of Exertional Dyspnea in Adult Pectus Excavatum Patients

Abstract:

Evaluation of patients with pectus excavatum has primarily been focused on the pediatric population who undergo surgical correction of sternal defects mainly for cosmetic reasons combined with exercise-limiting symptoms. The extent of cardiopulmonary improvement in this population based on cardiac imaging, pulmonary function testing, and cardiopulmonary exercise testing may be highly variable. There is no current consensus on the limitations of cardiopulmonary impairment or potential improvement from surgical repair in pediatric patients. Limited data has published in the medical literature on the evaluation of adults with pectus excavatum who may also present with a variety of clinical symptoms. Adult patients with exercise limitation and pectus excavatum may present with exertional dyspnea, chest discomfort, palpitations/tachycardia, exercise-induced wheezing, and use of bronchodilators for asthma-like symptoms. While numerous published review articles outline clinical evaluation and surgical treatment for younger patients, comprehensive evaluation for these adult patients has not been fully elucidated. There is no current consensus on the underlying cause of cardiopulmonary impairment in adult patients or their potential improvement from surgical repair. This review focuses on the recommended evaluation of adult patients to discern the potential cardiopulmonary limitations to exercise due to pectus excavatum, especially in physically fit adults such as active duty military personnel. Two illustrative cases are presented to describe the complexity of the evaluation of adult patients and potential need for surgical correction.

Left displacement of the mediastinum determines the imbalance in the pulmonary vascular bed and lung volume in children with pectus excavatum

The purpose of this study was to determine the influence of morphologic alteration on lung function in children with pectus excavatum (PE) and to establish the usefulness of chest radiography to predict the imbalance of pulmonary perfusion and lung volume. Chest radiography, pulmonary perfusion scintigraphy, and computed tomography (CT) for calculation of each lung volume were performed in 38 children with PE. To assess the relationship between position change of the mediastinum and lung, the following indices were calculated: (1) vertebral index (VI); the severity of sternal depression on the lateral chest radiograph, (2) left displacement index (LDI); the ratio between the left border of the mediastinum and the left border of the thorax to the transverse thoracic dimension on posterioanterior chest radiography; (3) left-to-right count ratio for the lung scintigraphy (Ls/Rs), and (4) the left-to-right thorax volume ratio from the CT scan (Lv/Rv). Compared to children without PE, VI was significantly higher, and LDI was lower in patients with PE. Pulmonary perfusion scintigraphy and CT showed that left pulmonary perfusion and lung volume were significantly lower than in the right lung in PE. LDI showed a close correlation with Ls/Rs (R = 0.443, P = 0.005) and Lv/Rv (R = 0.703, P < 0.001). Left displacement of the mediastinum within the closed thoracic cavity directly imposes constraints on the left lung, resulting in reductions of perfusion and lung volume that likely determine the physiologic severity of lung function in PE. Posterioanterior chest radiography might be useful in predicting the severity of PE.

Breath-hold MRI in evaluating patients with pectus excavatum

Pectus excavatum (PE) is a congenital condition in which the sternum is displaced posteriorly with associated changes in the adjacent costal cartilages. The aetiology of PE is uncertain although various underlying abnormalities of the diaphragm have been implicated. There is sparse information regarding the use of fast MRI in evaluating the deformity. Our aims were to use fast MRI to evaluate static and respiratory-related dynamic chest wall characteristics, the extent of cardiac displacement and diaphragmatic excursion in patients. FLASH and TurboFLASH MR sequences in axial and coronal planes were performed on the thoraces of six young patients with PE and six individually matched healthy controls during full inspiratory and full expiratory breath-holds. The Pectus Index was derived from chest wall measurements using axial images. The distances of the left and right cardiac borders from the midline were measured using axial images, and excursion of the dome of each hemidiaphragm was measured using coronal images. The degree of sternal depression worsened substantially in expiration. Anterior chest wall movement was similar in the two groups. Patients had significantly flatter chests than the controls. There was a trend towards leftward cardiac displacement in the patients (maximum distance between left heart border and midline during full expiration 99.5 mm in patients and 91.8 mm in controls). The right diaphragmatic dome excursion was greater than the left in the controls (53.6 mm and 47.4 mm, respectively), but this was not seen in the patients (50.2 mm and 50.4 mm, respectively). It is concluded that fast MRI is very informative in evaluating skeletal abnormalities, chest wall motion, and cardiac and diaphragmatic changes seen in PE.

Pectus excavatum: increase of right ventricular systolic, diastolic, and stroke volumes after surgical repair

OBJECTIVE

The study was undertaken to assess how a surgical correction of funnel chest modifies right ventricular structure and function.

METHODS

Before and 6 months after surgery in 42 patients (27 male and 15 female patients, aged 5-31 years), a pectus index was calculated and echocardiographic examinations of the right ventricle were performed, with calculation of systolic, diastolic, and stroke volume indices. Right ventricular volume was estimated by subtracting the left ventricular volume from that of the entire heart. The values of the right ventricular volumes and the pectus index before and after the operation, as well as the changes in the indices, were compared.

RESULTS

Statistically significant changes in the pectus index and the right ventricular volume indices after surgery were noted. No correlation was observed between the changes in the pectus index and the changes in any right ventricular volume indices.

CONCLUSION

Surgical treatment of funnel chest causes an increase in right ventricular systolic, diastolic, and stroke volumes, although there is no correlation between these changes and the degree of sternocostal elevation.

Cardiorespiratory function before and after corrective surgery in pectus excavatum

OBJECTIVE

To determine whether pectus excavatum (PE) results in cardiopulmonary abnormalities, and whether surgical repair results in improvement.

METHODS

We performed pulmonary function testing and incremental exercise testing in 36 adolescents with PE (aged 16 +/- 3 (SD) years) and 10 age-matched, healthy control subjects. Fifteen PE subjects were reexamined postoperatively, as were six control subjects.

RESULTS

Preoperatively, PE subjects had a significantly lower forced vital capacity than control subjects had (81% +/- 14% vs 98% +/- 9% of the predicted value; p < 0.001). Chest computed tomography ratios of internal transverse to antero-posterior diameters correlated inversely with total lung capacity (r = 0.56; p < 0.01). Fifty-eight percent of PE subjects had subjective complaints of exercise limitation. PE subjects exercised at a workload similar to that of control subjects. Maximal heart rate and O2 pulse did not differ between the two groups. Respiratory measurements during exercise were similar between the two groups. Respiratory measurements during exercise were similar between the two groups. Postoperatively there was no change in forced vital capacity (as a percentage of the predicted value). The PE subjects exercised for a slightly longer period and had a slightly higher O2 pulse, whereas control subjects showed no change.

CONCLUSION

Some subjects with PE have mild restrictive lung disease, which is not affected by surgical repair. Postoperatively they have a slight increase in exercise tolerance and O2 pulse, which suggests improved cardiac function during exercise. However, the clinical implications of this modest improvement are unclear.