Associated Comorbidities of Pectus Excavatum
Pectus excavatum is commonly associated with several cardiovascular and musculoskeletal comorbidities, most notably mitral valve prolapse, which occurs in approximately 15% of patients, and may indicate an underlying connective tissue disorder requiring thorough evaluation.
Cardiovascular Comorbidities
Mitral valve prolapse (MVP) is the most common cardiovascular comorbidity, occurring in up to 15% of patients with pectus excavatum 1. This association suggests a possible common disorder of connective tissue 2.
Tricuspid valve prolapse may coexist with MVP in approximately one-third of cases where MVP is present 2.
Aortic root enlargement can occur, particularly in patients with features of MASS phenotype (Mitral valve prolapse, Aortic root enlargement, Skin and Skeletal alterations) 3.
Cardiac compression or displacement due to the sternal depression may lead to functional cardiac abnormalities 1.
Bundle branch block or other cardiac conduction abnormalities may develop secondary to compression of the heart 1.
Musculoskeletal Comorbidities
Scoliosis is frequently observed in patients with pectus excavatum, suggesting a possible underlying connective tissue disorder 3.
Joint hypermobility is another common finding, further supporting the association with connective tissue disorders 4.
Thoracic skeletal abnormalities such as straight thoracic spine may coexist with pectus excavatum 4.
Connective Tissue Disorders
Pectus excavatum can be a feature of established connective tissue disorders such as:
- Marfan syndrome - approximately 5% of patients with severe pectus excavatum may have classical Marfan syndrome 3.
- Ehlers-Danlos syndrome - pectus excavatum is a common malformation in this condition 2.
- MASS phenotype - the largest group (approximately 71%) of patients with severe pectus excavatum demonstrate features of this phenotype 3.
Histological examination of skin biopsies in patients with pectus excavatum has shown abnormal collagen and elastin in 53% of cases, with collagen abnormalities being twice as common as elastin abnormalities 2.
Pulmonary Comorbidities
Restrictive lung disease may develop due to the chest wall deformity 1.
Exercise intolerance and shortness of breath with exertion are common symptoms 1.
Paradoxical respiratory chest wall motion can occur in severe cases 1.
Other Associated Conditions
Nontuberculous mycobacterial pulmonary disease, particularly with Mycobacterium avium complex, has been associated with a characteristic morphotype that includes pectus excavatum, particularly in postmenopausal women 4.
Familial pectus excavatum occurs as an autosomal dominant trait in some families, suggesting a genetic component 4.
Tall stature has been associated with pectus excavatum in some families with FBN1 mutations 4.
Clinical Implications and Management Considerations
Patients with pectus excavatum should be evaluated for underlying connective tissue disorders, particularly when other features such as MVP, scoliosis, or joint hypermobility are present 3.
Echocardiography is recommended to assess for MVP and other cardiac abnormalities 1.
Patients with pectus excavatum and features of connective tissue disorders may have higher rates of recurrence after surgical repair (39% in Marfan syndrome vs. 7% in isolated pectus excavatum) 5.
For patients with Marfan syndrome or other inherited connective tissue disorders, surgical repair should ideally be delayed until skeletal maturity is nearly complete and should employ internal stabilization to prevent recurrence 5.
Regular cardiovascular follow-up may be warranted in patients with pectus excavatum and MASS phenotype due to potential cardiovascular complications, even when initial aortic measurements are normal 3.