What is the most appropriate initial diagnostic test for a patient with dull chest pain that worsens with spicy meals, emotional stress, and lying flat, suggestive of gastroesophageal reflux disease (GERD)?

Establishing the Diagnosis in GERD-Related Chest Pain

For a patient with dull chest pain worsened by spicy meals, lying flat, and emotional stress—after cardiac causes have been excluded—upper endoscopy (Option B) is the most appropriate initial diagnostic test to establish the diagnosis. 1, 2

Diagnostic Algorithm

Step 1: Exclude Cardiac Causes First

• Cardiac evaluation must be completed before pursuing gastrointestinal workup, as chest pain from GERD can mimic myocardial ischemia with squeezing or burning quality lasting minutes to hours. 1, 2
• The morbidity and mortality of ischemic heart disease substantially exceeds that of esophageal disorders. 1

Step 2: Upper Endoscopy as Initial Test

• When an esophageal cause of chest pain is suspected based on symptoms worsened by spicy meals, lying flat, and emotional stress, upper endoscopy should be the initial diagnostic test. 1, 2
• Endoscopy directly visualizes esophageal mucosa to identify erosive esophagitis (graded by Los Angeles classification), strictures, Barrett's esophagus, and obtains tissue biopsies to detect microscopic inflammation. 1, 2
• Complete endoscopic evaluation includes inspection of the diaphragmatic hiatus (Hill grade), axial hiatus hernia length, and Barrett's esophagus assessment with Prague classification. 1

Step 3: Subsequent Testing Only If Endoscopy Is Normal

• Esophageal manometry (Option C) is reserved for evaluation after normal endoscopy when symptoms persist despite acid suppression. 1, 2
• Manometry serves to localize the lower esophageal sphincter for potential subsequent pH monitoring, evaluate peristaltic function preoperatively, and diagnose subtle presentations of major motor disorders like achalasia or distal esophageal spasm. 1

Step 4: pH Monitoring as Third-Line Test

• pH monitoring (Option D) is performed as the third diagnostic step after normal endoscopy and manometry. 1, 2
• Ambulatory 24-hour pH monitoring off PPI therapy (withheld for 7 days) is the most sensitive and specific test for detecting pathological esophageal acid exposure. 1
• Wireless pH monitoring has superior sensitivity to catheter studies due to extended recording period (48-96 hours preferred). 1

Why Not Barium Swallow (Option A)?

• Barium esophagography has limited diagnostic value because reflux can occur in more than 25% of asymptomatic patients. 3
• It is most useful for demonstrating structural abnormalities like strictures and hiatal hernia, not for establishing GERD diagnosis. 3
• Barium swallow may be the only test to reveal nonacid gastroesophageal reflux of potential pathologic significance, but this is a specialized indication. 1

Alternative Approach: Empiric PPI Trial

• If endoscopy cannot be performed immediately and alarm features (dysphagia, weight loss, gastrointestinal bleeding, unexplained anemia, recurrent vomiting) are absent, a 4-8 week trial of single-dose PPI therapy is reasonable. 1
• With inadequate response, dosing can be increased to twice daily or switched to a more effective acid suppressive agent. 1
• However, empiric PPI trials have poor diagnostic performance and should not be relied upon as a definitive diagnostic test. 2
• If PPI therapy is continued without proven GERD, appropriateness should be evaluated within 12 months, with endoscopy and prolonged wireless reflux monitoring off PPI offered to establish appropriate use of long-term therapy. 1

Critical Pitfalls to Avoid

• Symptoms are nonspecific and overlap extensively between GERD, gastritis, esophagitis, and peptic ulcer disease. 2
• Relief with antacids or antisecretory agents is suggestive but not sufficiently specific to be fully diagnostic. 1, 2
• Normal endoscopy findings do not rule out GERD as the cause of symptoms—further testing with manometry and pH monitoring may be needed. 1
• Obtain multiple esophageal mucosal biopsies (at least 5 from proximal and distal esophagus) during endoscopy to evaluate for eosinophilic esophagitis, which can present with normal-appearing mucosa and cause chest pain. 1, 4