Compromised cardiac function in exercising teenagers with pectus excavatum

Area of Science:

• Cardiology
• Pediatric Medicine
• Exercise Physiology

Background:

• Pectus excavatum is often associated with symptoms like dyspnea and fatigue.
• The underlying pathophysiology and its impact on cardiac function during exercise remain unclear.

Purpose of the Study:

• To investigate cardiac function and exercise capacity in teenagers with pectus excavatum compared to healthy controls.
• To determine if pectus excavatum affects cardiopulmonary function during rest and submaximal exercise.

Main Methods:

• Investigated 75 teenagers (49 with pectus excavatum, 26 controls) at rest and during bicycle exercise.
• Assessed resting cardiac function via echocardiography.
• Measured cardiac output, heart rate, and aerobic exercise capacity non-invasively using photo-acoustic gas-rebreathing during rest and exercise.

Main Results:

• No significant cardiac differences were observed between groups at rest.
• During submaximal exercise, pectus excavatum patients had a significantly lower cardiac index (6.6 vs. 8.0 L/min/m²).
• This reduction in cardiac output was attributed to a lower stroke index (42 vs. 54 mL/beat/m²) in patients, while heart rate remained unchanged.

Conclusions:

• Cardiac function is significantly impaired in patients with pectus excavatum during submaximal exercise compared to healthy controls.
• The findings suggest that reduced stroke volume, not heart rate, is the primary factor limiting exercise capacity in these patients.
• This study provides objective evidence for exercise limitations in pectus excavatum, supporting patient-reported symptoms.