What is the likely cause of episodic chest pain and shortness of breath in a patient with an RSR pattern on ECG, significant anxiety, and a family history of heart disease, presenting with sharp mid-sternal pain and worsening dyspnea on deep inspiration, especially when lying down?

RSR Pattern on ECG in an Adolescent with Pleuritic Chest Pain and Anxiety

The RSR' pattern found on this patient's ECG most likely represents an incomplete right bundle branch block (IRBBB), which is a common benign variant in children and adolescents, and the episodic chest pain is most consistent with anxiety-related chest pain given the sharp, pleuritic quality, positional nature (worse lying down), significant psychosocial stressors, and GAD-7 score of 12. 1

Understanding the RSR' Pattern in This Clinical Context

The RSR' pattern is a normal variant in pediatric patients and does not indicate cardiac pathology in the absence of structural heart disease. This ECG finding represents delayed right ventricular conduction and is commonly seen in healthy children and adolescents. 1

Key Clinical Features Against Cardiac Ischemia

The chest pain characteristics strongly argue against acute coronary syndrome:

• Sharp, mid-sternal pain that worsens with deep inspiration and lying supine is unlikely related to ischemic heart disease 1
• Pain occurring exclusively at rest while lying in bed, never with activity, contradicts typical anginal patterns 1
• No pressure, squeezing, or heaviness quality 1
• No radiation to arms, jaw, or back 1
• No diaphoresis during episodes 1
• Duration of 30 minutes with complete resolution is atypical for ACS 1

The Anxiety Connection

For patients with recurrent, similar presentations for acute chest pain with no evidence of a physiological cause on prior diagnostic evaluation, referral to a cognitive-behavioral therapist is reasonable. 1

This patient demonstrates multiple high-risk features for anxiety-related chest pain:

• GAD-7 score of 12 indicates moderate anxiety requiring intervention 1
• Multiple significant psychosocial stressors: family illness, bullying at school, changes at home, IEP requirements 1
• Sharp chest pain that increases with inspiration and lying supine is unlikely related to ischemic heart disease 1
• Pattern of symptoms occurring at rest, particularly when lying down trying to sleep, is classic for anxiety-related chest pain 1

Anxiety disorders are associated with cardiovascular symptoms through autonomic dysfunction, and the timely identification and treatment of these conditions is of utmost importance. 2

Critical Differential Diagnoses to Exclude

Pericarditis

Sharp, pleuritic chest pain that worsens when supine and improves when leaning forward is the hallmark of pericarditis. 1, 3

This patient's presentation has features consistent with pericarditis:

• Sharp pain worse with inspiration 1
• Worse when lying supine 1, 3
• Mid-sternal location 1

However, the ECG should show widespread ST-elevation and PR depression in pericarditis, which you should specifically look for on the ECG interpretation. 4 The absence of fever and friction rub makes pericarditis less likely. 1

Pulmonary Embolism

Pulmonary embolism presents with tachycardia and dyspnea in >90% of patients, with pleuritic pain on inspiration. 4, 5

Against PE in this case:

• Normal vital signs (HR 70, O2 sat 99%) 4
• No tachycardia or tachypnea 4
• No risk factors for thromboembolism 4
• Symptoms exclusively at rest, never with activity 4

Pneumothorax

Pneumothorax is characterized by dyspnea, pleuritic pain on inspiration, and unilateral absence of breath sounds. 1, 4

Against pneumothorax:

• Lungs clear to auscultation bilaterally 1
• No unilateral findings 1
• Chest X-ray will definitively exclude this 1

Algorithmic Approach to This Patient

Immediate Actions (Already Appropriately Ordered)

1. ECG interpretation must focus on:

   • Confirming RSR' pattern is incomplete right bundle branch block (benign variant) 1
   • Excluding ST-segment elevation, new ischemic changes, or widespread ST-elevation with PR depression 1, 4
   • Documenting rhythm (noted as "regular, irregular" which needs clarification) 1

2. Chest X-ray to exclude:

   • Pneumothorax 1
   • Pneumonia 1
   • Cardiomegaly (unlikely given exam) 1

3. Cardiac biomarkers are NOT indicated in this low-risk presentation with atypical features and normal vital signs 1, 6

Risk Stratification

This patient is LOW RISK for acute coronary syndrome based on:

• Age (pediatric/adolescent) 1
• Atypical pain characteristics (sharp, pleuritic, positional) 1
• No pain with exertion 1
• Normal vital signs 1
• No high-risk features (no diaphoresis, no hemodynamic instability) 1

The Marburg Heart Score and INTERCHEST clinical decision rule can help estimate ACS risk, but this patient would score very low on both. 6

Management Plan Based on Test Results

If ECG shows only IRBBB and chest X-ray is normal:

1. Reassure that cardiac cause is extremely unlikely 1, 6
2. Address anxiety as primary driver of symptoms:
   • Referral to cognitive-behavioral therapist is reasonable for recurrent chest pain with negative cardiac workup 1
   • Consider involving school counselor given bullying and IEP issues 1
   • Family therapy may help address home stressors 1
3. Educate on anxiety-related chest pain mechanisms 1, 2
4. Provide clear return precautions 1

If ECG shows widespread ST-elevation with PR depression (pericarditis):

• Consider anti-inflammatory therapy with ibuprofen 600-800mg TID or colchicine 3
• Follow-up in 1-2 weeks 3
• Echocardiogram if concern for pericardial effusion 3

Critical Pitfalls to Avoid

Women, elderly patients, and those with diabetes may present with atypical symptoms, but this does not apply to pediatric patients where atypical presentations are even less concerning for ACS. 1, 3

Do not use nitroglycerin response as a diagnostic criterion, as esophageal spasm and other conditions also respond to nitroglycerin. 1, 3

Approximately 7% of patients with reproducible chest wall pain still have acute coronary syndrome, but this applies to adult populations, not pediatric patients with this clinical presentation. 4

The irregular rhythm noted on exam requires clarification - if this represents frequent premature atrial or ventricular contractions, this could be anxiety-related, but sustained arrhythmias would require further evaluation. 1

Family History Considerations

The family history of congestive heart failure and possible heart disease warrants documentation but does not change acute management in this low-risk presentation. 1 This family history becomes relevant for:

• Long-term cardiovascular risk assessment 1
• Screening for familial cardiomyopathies if structural heart disease is suspected 1
• Not applicable to acute chest pain evaluation in this atypical presentation 1

Addressing the Gastrointestinal Component

The history of nausea and previous GERD symptoms (resolved with Prevacid) suggests:

• Gastroesophageal reflux disease can cause chest pain, but typically presents as burning retrosternal pain related to meals 3, 7
• Current symptoms (sharp, pleuritic, positional) are not consistent with GERD 3
• Ongoing nausea may be anxiety-related 1

Return Precautions

Advise return to care urgently for:

• Persistent chest pain lasting >20 minutes 1
• Syncope or presyncope 1
• Chest pain with exertion 1
• Worsening dyspnea at rest 1
• Fever with chest pain (suggests pericarditis or pneumonia) 1
• Hemodynamic instability 1