A sunken chest, medically termed Pectus Excavatum, is a common congenital chest wall deformity where the breastbone (sternum) is caved inward. The indentation can range from slight to deep. Though often present from birth, it may become more noticeable during rapid growth, such as adolescence. This article explores its causes, associated conditions, health implications, and when to seek medical advice.
Pectus Excavatum The Primary Cause
Pectus excavatum is the most frequent congenital chest wall abnormality, accounting for about 95% of pectus deformities. It occurs in 1 to 8 per 1,000 live births and is more common in males. The condition is a developmental anomaly, arising from an irregularity in development.
The exact cause of pectus excavatum is not fully understood; in most cases, it is considered idiopathic. However, a widely accepted theory suggests it involves an abnormal growth or overgrowth of the costal cartilages, the flexible tissues connecting ribs to the sternum. This excessive growth causes the sternum to be pushed inward.
A genetic predisposition is suggested by a positive family history in over 40% of cases. The deformity can be visible at birth or become more pronounced during childhood and adolescent growth spurts. Severity varies greatly, from a subtle indentation to a significant depression, which may be symmetrical or asymmetrical.
Other Underlying Conditions
While pectus excavatum often occurs as an isolated anomaly, it can also be a feature of certain medical conditions or genetic syndromes. These conditions involve connective tissue disorders or skeletal dysplasias, affecting structural components. In these instances, the sunken chest is one of several symptoms within a broader clinical picture.
Marfan syndrome, a genetic disorder affecting connective tissue, frequently presents with pectus excavatum, affecting up to 70% of individuals. This syndrome leads to tall, thin body types with long limbs, flexible joints, and potential cardiac and ocular issues. Similarly, Ehlers-Danlos syndromes, inherited connective tissue disorders characterized by joint hypermobility and skin laxity, can also be associated with pectus deformities.
Poland syndrome is another condition that can involve chest wall deformities, though it presents with underdevelopment or absence of chest muscles on one side, resulting in a sunken appearance. Other rare genetic conditions like Noonan syndrome and Loeys-Dietz syndrome, both affecting connective tissue, have also been linked to pectus excavatum. In some instances, severe scoliosis, a spinal curvature, can indirectly influence chest shape by affecting rib alignment and contributing to a sunken appearance.
Health Implications
A sunken chest can lead to both physical and psychological effects, its impact often correlating with the degree of sternal indentation. In moderate to severe cases, the inward displacement of the breastbone can compress the heart and lungs, affecting their function. This compression may reduce lung capacity, making breathing difficult, especially during exertion. Individuals may experience shortness of breath, fatigue, or reduced exercise tolerance.
The heart can also be affected, as sternal pressure may shift its position or impede efficient blood pumping. This can lead to symptoms like chest pain, irregular heartbeats, or heart palpitations. While mild cases may not cause significant physical symptoms, even a slight indentation can lead to psychological and social challenges. Individuals, particularly adolescents, may experience self-consciousness, body image concerns, and social anxiety, sometimes leading them to avoid activities exposing their chest.
When to Consult a Professional
Seeking medical evaluation for a sunken chest is advisable to determine its severity, identify underlying conditions, and discuss management options. A healthcare professional can diagnose pectus excavatum through a physical examination, often sufficient for initial assessment. However, additional diagnostic tests are often recommended to understand the condition’s impact on internal organs.
Imaging studies like chest X-rays, CT scans, or MRI scans can provide precise measurements of the chest deformity and assess compression or displacement of the heart and lungs. Pulmonary function tests evaluate lung capacity, while echocardiograms assess heart function. These tests help determine if the condition causes physical symptoms or is primarily a cosmetic concern. Management approaches vary depending on the severity and symptoms, ranging from observation and physical therapy for mild cases to surgical interventions for severe cases affecting health or quality of life.