A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / compression of the right atrium and ventricle yet their LV function is within normal range. In the setting of normal LV function, symptomatic PE could potentially be the result of right heart compression causing right heart strain. Emphasis should therefore be placed on analyzing the presence and degree of right heart strain in patients with symptomatic pectus excavatum. When assessing for a correlation between the HI, CI, DI, or CCI together and independently with cardiopulmonary impairment, no significant relationships were identified. While it would be highly advantageous for a PE severity index to correlate with objective physiologic impairment, our data suggest that the currently defined indices fail to do so. Data confirming such a correlation would provide a means to measure both the severity of deformity and changes in functional disability in patients with PE. We aim to analyze the correlation between the HI and three new indices with cardiopulmonary impairment using the cardiopulmonary exercise test (CPET). In this study we evaluated the correlation of the Haller, correction, depression, and cardiac compression indices with functional cardiopulmonary impairment using preoperative cardiopulmonary exercise test (CPET) data. We hypothesize that the correction and cardiac compression indices will be strongly correlated with physiologic impairment in patients with PE, thus providing a novel means to measure functional disability as a function of disease severity. Study Design This is a retrospective study of 71 children between the ages of birth and 18 years of age who underwent evaluation for corrective surgery for pectus excavatum between 2010 and 2016 at Phoenix Children’s Hospital. Our final sample underwent preoperative computed tomography (CT) or MRI scan results as well as cardiopulmonary exercise testing. For each patient, the HI, CI, DI, and CCI were independently assessed using the PACS System by a single rater. Preoperative functional capacity was determined by measurement of peak oxygen consumption (VO2max reported as percent predicted) and stroke volume (a surrogate for cardiac output) which was assessed via the O2 pulse (VO2max/heart rate) reported as percent predicted. The possible values range from zero to 100% of the predicted value. Assessments Halller Index Correction Index Depression Index Cardiac Compression Index Correction, Depression, Cardiac Compression and Haller Indices Fail to Correlate with Cardiopulmonary Impairment in Pectus Excavatum Abstract Results Background: Pectus excavatum (PE) affects 1 in every 300 to 1,000 live births with a male to female ratio of 5:1, making it the most common congenital chest wall deformity in children. The standard for determining disease severity has become the Haller Index, which has been shown to poorly correlate with physiologic impairment. Recently, more novel indices have been introduced in an effort to more effectively represent disease burden. We aim to analyze the correlation between these indices and cardiopulmonary impairment in patients with PE using chest CT/ MRI as well as preoperative cardiopulmonary exercise testing data. Conclusions: We found that when assessing for a correlation between the HI, CI, DI, or CCI together and independently with cardiopulmonary impairment, both the linear and multiple regression models failed to identify a statistically significant relationship. While it would be highly advantageous for a PE severity index to correlate with objective physiologic impairment, our data suggest that the currently defined indices fail to do so.