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Quantitative QRS changes with exercise in children and adolescents.
1Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030.
Medicine and Science in Sports and Exercise
|April 1, 1990
Summary
Exercise alters QRS voltage in children and adolescents, differing from adult responses. Younger males showed increased or unchanged R wave voltage during exercise, unlike older males and adults.
Area of Science:
- Pediatric Cardiology
- Exercise Physiology
- Electrocardiography
Background:
- Exercise-induced QRS voltage changes are utilized to assess left ventricular function in various age groups.
- Understanding these changes in pediatric populations is crucial for accurate cardiac evaluation.
Purpose of the Study:
- To investigate exercise-induced alterations in QRS voltage within a cohort of healthy children and adolescents.
- To compare these pediatric responses with known adult patterns.
Main Methods:
- Maximal exercise testing (Bruce protocol) was conducted on 82 healthy subjects (ages 4-18).
- Continuous electrocardiogram (ECG) monitoring (leads V1, V2, V5) and 12-lead ECGs were recorded at each exercise stage.
- Resting and exercise QRS voltages (Vf and V5) and frontal/horizontal QRS vectors were analyzed.
Main Results:
- A posterior shift in the horizontal QRS vector occurred at peak exercise (mean 14.5 degrees, P < 0.001).
- R wave voltage in lead V5 decreased significantly (mean 0.39 mV, P < 0.001), but remained unchanged or increased in 72% of boys ≤10 years old.
- These exercise-induced ECG changes in children and adolescents differed notably from those observed in healthy adults.
Conclusions:
- Exercise elicits distinct QRS voltage and vector changes in children and adolescents compared to adults.
- Age and sex appear to influence the magnitude and direction of these exercise-induced electrocardiographic alterations in the pediatric population.