What does an EKG (electrocardiogram) result showing sinus tachycardia, right axis deviation, possible right ventricular hypertrophy, and borderline nonspecific ST (stress test) and T wave abnormality mean for a 15-month-old child?

Interpretation of EKG Findings in a 15-Month-Old Child

The EKG findings in this 15-month-old child suggest possible congenital heart disease requiring prompt cardiology referral for comprehensive evaluation, as these findings may indicate right-sided heart pressure or volume overload.

Analysis of Individual EKG Findings

Sinus Tachycardia

• Sinus tachycardia in infants can be physiologic (fever, anxiety, pain) but may also indicate underlying cardiac or pulmonary disease
• Normal heart rate for a 15-month-old ranges from 80-130 bpm; persistent rates above this threshold warrant investigation 1

Right Axis Deviation

• Right axis deviation is common in infants but should normalize with age
• In a 15-month-old, right axis deviation may be normal or may indicate right ventricular pressure or volume overload 2
• According to pediatric criteria, right axis deviation (>120°) is considered a borderline ECG finding that may require further investigation when combined with other abnormalities 2

Possible Right Ventricular Hypertrophy (RVH)

• RVH in children is primarily associated with congenital heart disease, with highest diagnostic accuracy in this population 2
• Age-specific criteria must be applied when evaluating for RVH in infants and children 2
• For children aged 7 days to 1 year, RVH criteria include:
  • R wave in V1 ≥22 mm
  • S wave in V6 ≥10 mm
  • Sum of RV1 and SV6 ≥43 mm 2
• The sensitivity of ECG for detecting RVH is relatively low (69%), even when using age-appropriate criteria 3

Borderline Nonspecific ST and T Wave Abnormality

• ST-T wave abnormalities in the right precordial leads often accompany RVH in children with congenital heart disease 2
• These changes are better referred to as "secondary ST-T abnormalities" rather than "strain" 2
• Nonspecific ST-T changes can occur in various conditions and may not be distinguishable from those caused by structural heart disease 4

Clinical Implications

The combination of these findings raises concern for:

1. Congenital heart disease - particularly those causing right ventricular pressure or volume overload:

   • Atrial septal defect
   • Ventricular septal defect
   • Pulmonary stenosis
   • Tetralogy of Fallot

2. Pulmonary hypertension - which can be:

   • Primary (rare in children)
   • Secondary to congenital heart disease
   • Secondary to respiratory disease 2

3. Arrhythmogenic right ventricular dysplasia - although rare in infants, can present with right ventricular abnormalities and T-wave inversions 5

Recommended Evaluation

1. Echocardiography - Essential first-line imaging to:

   • Assess right ventricular size and function
   • Evaluate for congenital heart defects
   • Estimate pulmonary artery pressures
   • Assess for biventricular involvement 2

2. Clinical correlation with:

   • Respiratory symptoms (tachypnea, cyanosis, respiratory distress)
   • Growth parameters
   • Oxygen saturation
   • Blood pressure measurements

3. Consider additional testing based on initial findings:

   • 24-hour Holter monitoring
   • Exercise testing (modified for age)
   • Cardiac MRI if structural abnormalities are suspected 2

Important Considerations

• The presence of multiple borderline ECG findings (right axis deviation + possible RVH) increases the likelihood of underlying cardiac pathology 2
• ECG findings must be interpreted in the context of age-specific norms; what is abnormal in adults may be normal in infants 2
• The sensitivity of ECG for detecting RVH is limited, so normal ECG findings do not exclude significant cardiac disease 3

Conclusion

This ECG pattern in a 15-month-old warrants prompt cardiology evaluation, as it may represent early manifestation of congenital heart disease or other cardiac pathology that could impact morbidity and mortality if left undiagnosed and untreated.