What is considered a normal result in echocardiography (echo) despite an abnormal finding?

Normal Findings in Echocardiography Despite Apparent Abnormalities

Several findings on echocardiography may appear abnormal but are actually normal variants that do not require intervention or indicate pathology.

Common Normal Variants in Echocardiography

Physiological Findings Often Misinterpreted as Abnormal

• Sinus arrhythmia or isolated extrasystoles in children with otherwise normal cardiac findings and no family history of genetically transmitted abnormalities associated with arrhythmia 1
• Short, soft murmur at the lower left sternal border in neonates is typically innocent and does not indicate pathology 1, 2
• Mild mitral valve prolapse is the most common finding (4.6% to 18.5% of cases) in patients with syncope or pre-syncope who have normal physical examinations 1

Normal Variants in Pediatric Populations

• Acrocyanosis with normal upper and lower extremity oxygen saturations is a normal finding 1
• Patent foramen ovale in infants, which typically closes within the first year of life
• Physiologic tricuspid regurgitation (mild, non-pathological)
• Coronary sinus dilation without hemodynamic significance

When to Consider Findings as Normal

Clinical Context Matters

1. Normal clinical and radiologic examination predicts absence of significant cardiac abnormalities with 100% negative predictive value 3
2. Functional murmurs can usually be distinguished from organic murmurs by experienced clinicians 4
3. Absence of symptoms in the presence of minor echocardiographic findings often indicates a normal variant

Age-Specific Considerations

• In neonates and infants, certain findings resolve spontaneously:
  • Small muscular ventricular septal defects often close on their own
  • Mild pulmonary branch stenosis typically improves with growth
  • Persistent fetal circulation patterns in the first days of life

Potential Pitfalls in Interpretation

Caution Areas

1. Combined cardiac lesions may be missed if focus is on a single finding - cardiac examination has limited ability to assess exact cause of murmurs when multiple lesions are present 4
2. Severe left ventricular dysfunction can mask the severity of aortic stenosis on clinical examination 4
3. Clinically innocent murmurs may occasionally be associated with significant cardiac abnormalities that would be missed without echocardiography 5

Technical Considerations

• Limited acoustic windows can create apparent abnormalities
• Respiratory variation may affect measurements
• Patient positioning can alter apparent chamber sizes

Decision Algorithm for Interpreting Echo Findings

1. Evaluate clinical context:

   • Are there symptoms or abnormal physical findings?
   • Is there a family history of cardiac disease?

2. Consider age-appropriate norms:

   • Different chamber dimensions and wall thicknesses are normal at different ages
   • Heart rate and cardiac output vary significantly with age

3. Assess hemodynamic significance:

   • Is there evidence of altered blood flow?
   • Are there pressure or volume overload signs?

4. Follow-up recommendations:

   • Minor variants without clinical significance: no follow-up needed
   • Borderline findings: consider repeat imaging at appropriate intervals

Conclusion

When interpreting echocardiography results, it's essential to distinguish between normal variants and true pathology. Many findings that may initially appear concerning represent normal physiological variations, especially when clinical examination is normal. Understanding these normal variants prevents unnecessary anxiety, additional testing, and interventions.