Pectus excavatum is a common congenital chest wall malformation where the breastbone (sternum) and attached ribs grow inward, creating a sunken appearance in the center of the chest. The condition is sometimes referred to as funnel chest. While the aesthetic appearance is often the most noticeable feature, the indentation can also have functional consequences on the body’s internal systems. In more significant cases, the altered chest structure impacts the function of the heart, lungs, and surrounding skeletal structures.
Effects on Breathing and Lung Capacity
The inward curvature of the sternum directly reduces the physical volume of the thoracic cavity, which is the space housing the lungs. This anatomical restriction limits the amount of room available for the lungs to fully expand, particularly during periods of maximum effort. The chest wall deformity can lead to a restrictive pattern of breathing, meaning the lungs cannot hold as much air as they should.
This mechanical limitation often manifests as shortness of breath (dyspnea), especially when exerting energy during physical activity. Affected individuals may experience reduced vital capacity, which is the maximum amount of air a person can exhale after a maximum inhalation. The inability of the lungs to fully inflate and deflate efficiently contributes to decreased exercise tolerance and easy fatigability.
The mechanism for this reduced function is partly due to the depressed portion of the chest wall not moving properly during respiration, which impedes the bellows-like action of the thoracic cage. This decreased efficiency forces the body to work harder to achieve adequate oxygen and carbon dioxide exchange. This physical constraint on lung movement can significantly impair a person’s stamina.
Effects on Heart Function
The cardiac system is directly affected by the physical presence of the sunken sternum, especially in moderate to severe cases. The inward depression physically compresses the heart, most commonly affecting the right side, and may cause the heart to rotate or shift toward the left side of the chest. This compression limits the space available for the heart’s chambers, particularly the right ventricle, to fill completely with blood during diastole.
The consequence of this limited filling is a reduction in the heart’s stroke volume, the amount of blood ejected with each beat. To compensate, the heart must increase its rate to maintain sufficient cardiac output, especially during exercise. This compensatory mechanism can lead to symptoms like heart palpitations, an irregular heartbeat, or chest pain during exertion.
Compression of the heart can also sometimes cause an audible heart murmur due to the proximity of the sternum to the pulmonary artery. In some cases, it may be associated with valvular issues like mitral valve prolapse. Studies show a correlation between the severity of the chest wall deformity and the degree of cardiac compression. Surgical correction often leads to an increase in stroke volume and exercise capacity, further indicating the mechanical nature of the heart impairment.
Impacts on Musculoskeletal Structure and Posture
The abnormal growth of the sternum and costal cartilage can lead to secondary structural issues extending beyond the chest cavity. Many people with this condition develop a characteristic “pectus posture,” which typically involves rounded, forward-sloping shoulders and an increased forward curvature of the upper spine (kyphosis). This posture relates to muscular imbalances and the altered shape of the rib cage.
The deformity is also frequently associated with scoliosis, a sideways curvature of the spine. The uneven pressure or tension created by the altered chest structure can contribute to chronic back pain, which is usually musculoskeletal in origin. Other physical manifestations include asymmetry of the shoulders and flared ribs, where the lower ribs protrude outward.
Psychological and Quality of Life Concerns
Beyond the physical effects, living with a visible chest wall deformity can significantly impact an individual’s emotional and social well-being. Concerns about body image are prevalent, especially during adolescence when the condition often becomes more pronounced. This self-consciousness can lead to feelings of shame and a tendency to hide the chest defect, often by choosing specific clothing or maintaining a poor, hunched posture.
The resulting emotional distress frequently manifests as lower self-esteem, increased social anxiety, and introversion. Many affected individuals avoid activities that expose their chests, such as swimming or participating in certain sports, which limits social engagement and physical activity. Research indicates that this body image distress and associated social anxiety can negatively affect the overall quality of life.