In a 12‑year‑old with intermittent exertional chest pain, no shortness of breath, dizziness, or syncope, and spirometry showing forced expiratory volume in one second (FEV1) 39 % of predicted, forced vital capacity (FVC) 63 % of predicted, and FEV1/FVC ratio 0.556 (below the lower limit of normal 0.803), is a cardiac referral indicated?

Yes, a cardiac referral is appropriate for this 12-year-old with exertional chest pain and severely abnormal spirometry.

This child requires urgent cardiac evaluation despite the absence of syncope or dizziness, because the spirometry results show severe restrictive lung disease (FEV1 39%, FVC 63%) that is disproportionate to typical exercise-induced bronchoconstriction, and cardiac causes must be excluded before attributing symptoms solely to pulmonary pathology.

Critical Clinical Reasoning

Why Cardiac Referral is Indicated

The spirometry pattern is highly concerning and atypical for common pediatric respiratory conditions:

• Severe reduction in both FEV1 (39% predicted) and FVC (63% predicted) suggests restrictive physiology rather than pure obstructive disease
• FEV1/FVC ratio of 0.556 is below LLN (0.803), but the proportional reduction in both parameters indicates this is not typical asthma
• Exertional chest pain in the context of such severe pulmonary function abnormalities raises concern for cardiac etiologies that can present with both respiratory and cardiac symptoms

Guideline-Based Differential Diagnosis

The 2016 Exercise-Induced Bronchoconstriction guidelines explicitly state: "Appropriate cardiopulmonary testing and referral to an appropriate specialist might be required when breathlessness with exercise with or without chest pain is caused by these mechanisms in the absence of EIB" 1. The guidelines emphasize that providers must "perform spirometry and a focused detailed physical examination if shortness of breath with exercise is associated with underlying conditions, such as chronic obstructive pulmonary disease (COPD) or restrictive lung conditions" 1.

Cardiac Causes That Must Be Excluded

The 2016 EIB guidelines specifically warn about cardiac conditions masquerading as respiratory disease 1:

• Idiopathic pulmonary arterial hypertension can demonstrate peripheral airway obstruction and reversibility in children
• Congenital heart disease and coronary anomalies cause exertional chest pain
• Left ventricular outflow obstruction presents with exercise-related symptoms
• "Cardiac asthma" from cardiogenic pulmonary edema can mimic respiratory disease

Recent case reports confirm that isolated left main coronary artery ostial stenosis can present as exertional chest pain in children 2, and the 2007 AHA screening guidelines identify exertional chest pain as a red flag requiring cardiovascular evaluation 3.

Recommended Diagnostic Algorithm

Immediate Steps:

1. Refer to pediatric cardiology for comprehensive cardiac evaluation including:

   • Detailed cardiac history focusing on exertional symptoms
   • ECG to screen for channelopathies, hypertrophic cardiomyopathy, WPW
   • Echocardiography to assess structural heart disease, ventricular function, and pulmonary artery pressures
   • Consider cardiopulmonary exercise testing if initial workup is inconclusive

2. Verify spirometry quality - The 2021 ERS guidelines note that "not all children are able to perform a sufficient FVC manoeuvre, resulting in a false normal FEV1/FVC ratio" 4. However, in this case, both values are severely reduced, making technical error less likely.

3. Repeat spirometry with bronchodilator response testing to assess for reversibility, though the severity suggests this is not simple exercise-induced bronchoconstriction 4.

Parallel Pulmonary Evaluation:

While cardiac workup proceeds, consider:

• Chest imaging (chest X-ray or CT) to evaluate for restrictive lung disease, interstitial processes, or vascular abnormalities
• Pulmonary consultation if cardiac evaluation is negative, to investigate restrictive lung diseases, interstitial lung disease, or chest wall abnormalities

Critical Pitfalls to Avoid

1. Do not assume this is asthma or exercise-induced bronchoconstriction - The spirometry pattern (severe reduction in both FEV1 and FVC) is inconsistent with typical EIB, which shows normal baseline spirometry 1

2. Do not delay cardiac evaluation - Exertional chest pain with abnormal pulmonary function can indicate serious cardiac pathology including coronary anomalies or cardiomyopathy 1, 2

3. Do not attribute symptoms to anxiety or musculoskeletal causes without excluding life-threatening cardiac and pulmonary conditions first 1

4. Do not start empiric asthma treatment without confirming diagnosis - The 2021 ERS guidelines recommend against diagnosis based on symptoms alone and emphasize objective testing 4

Evidence Quality Assessment

The recommendation for cardiac referral is supported by:

• Strong guideline evidence from 2016 EIB guidelines 1 and 2007 AHA screening recommendations 3 identifying exertional chest pain as requiring cardiac evaluation
• Moderate quality evidence from 2021 ERS pediatric asthma guidelines 4 establishing that severely abnormal spirometry requires comprehensive evaluation beyond asthma
• Case report evidence 2 demonstrating that coronary anomalies can present with isolated exertional chest pain in children

The severely abnormal spirometry (FEV1 39%, FVC 63%) combined with exertional chest pain creates a clinical scenario where cardiac pathology must be definitively excluded before attributing symptoms to respiratory causes alone.