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[The electrocardiogram of the normal child]
Insights
Electrocardiogram (EKG) analysis in children reveals that QRS voltage and duration are unreliable for diagnosing ventricular hypertrophy. Initial intrinsicoid deflection time in specific leads offers more accurate diagnostic criteria for this condition.
Area of Science:
- Pediatric Cardiology
- Clinical Electrophysiology
- Diagnostic Criteria Development
Context:
- Electrocardiograms (EKGs) are essential for assessing pediatric cardiac health.
- Accurate diagnosis of ventricular hypertrophy in children is crucial for timely intervention.
- Existing EKG criteria for ventricular hypertrophy in pediatric populations require refinement.
Purpose:
- To establish reliable EKG criteria for diagnosing ventricular hypertrophy in normal children aged 1 month to 10 years.
- To evaluate the diagnostic utility of QRS voltage, QRS duration, and intrinsicoid deflection time.
- To compare findings with previously reported EKG values in pediatric literature.
Summary:
- QRS voltage and duration in precordial leads are highly variable and not adequate for diagnosing ventricular hypertrophy in children.
- Intrinsicoid deflection time in leads V1, aVF, and V6 demonstrates significant clinical relevance.
- Specific intrinsicoid deflection time values in V1 (18-20 msec) and V6 (20-31 msec, varying by age) can indicate right or left ventricular hypertrophy, respectively.
Impact:
- Provides refined EKG diagnostic criteria for pediatric ventricular hypertrophy.
- Enhances the accuracy of non-invasive cardiac assessments in children.
- Contributes to earlier and more precise management of pediatric heart conditions.
Abstract:
The EKG findings of 202 normal children, aged 1 month to 10 years were reviewed in order to determine criteria for diagnosis of ventricular hypertrophy. QRS voltage in right and left precordial leads are very variable and do not constitute adequate criteria for the diagnosis of ventricular hypertrophy the same is true with QRS duration, which increases progressively from 50 to 60 msec from the first to the fourth year of life, and to 70 msec over that age. The values found are smaller than those previously reported in the literature. Measurement of initial intrinsicoid deflection time in leads VI, aVF and V6 apparently have important clinical significance. This is a constant finding in normal hearts in lead VI, where deflection time is 18 to 20 msec. Therefore, times above 25 to 30 msec are sugestive of right ventricular hypertrophy when RBBB is not present. Intrinsicoid deflection time in lead V6 in children under one year of age was 20 msec, while between age one and ten it varied between 20 and 31 msec. Such variations show how left ventricular tissue increases after the first years of life, and also that times above 5 msec over those found for any age group are indicative of left ventricular hypertrophy.