What is the differential diagnosis (ddx) for a patient presenting with excessive belching, left-sided chest pain, and side pain?

Differential Diagnosis for Excessive Belching with Left-Sided Chest and Side Pain

The differential diagnosis must prioritize life-threatening cardiac and pulmonary causes first, followed by gastrointestinal disorders, with excessive belching suggesting either gastroesophageal reflux disease with gastric belching or supragastric belching as a behavioral disorder. 1

Life-Threatening Causes to Exclude Immediately

Acute coronary syndrome (ACS) must be ruled out first, even though left-sided chest pain with belching may suggest a gastrointestinal etiology, as more than half of ED chest pain presentations ultimately have noncardiac causes but 5.1% have ACS. 1

• Obtain ECG within 10 minutes and measure cardiac troponin immediately, as left-sided chest pain can represent myocardial ischemia, particularly in women, elderly patients, and those with diabetes who may present with atypical symptoms including upper abdominal pain. 1, 2

• Pulmonary embolism presents with acute dyspnea, pleuritic chest pain, and tachycardia in >90% of patients; use Wells or Geneva score to determine pretest probability and obtain D-dimer if low-to-intermediate risk. 3, 2, 4

• Acute pericarditis causes sharp, pleuritic left-sided chest pain that worsens when supine and improves leaning forward, with friction rub on examination. 1, 2

• Pneumothorax presents with dyspnea, pain on inspiration, and unilateral absence of breath sounds. 1, 2

Gastrointestinal Causes (Most Likely Given Excessive Belching)

Gastroesophageal reflux disease (GERD) is the most relevant condition associated with both types of belching and can cause chest pain that mimics cardiac ischemia. 1, 5

Two Types of Belching to Differentiate:

• Gastric belching (involuntary): Physiological mechanism to vent swallowed air from the stomach, occurs less frequently and with greater force than supragastric belching; consider PPI therapy if related to GERD. 1

• Supragastric belching (voluntary): Behavioral disorder where high-resolution manometry shows upper esophageal relaxation with air flowing into esophagus then expelled orally through pharynx before reaching stomach; requires brain-gut behavioral therapy rather than PPIs. 1, 5

Ambulatory impedance monitoring +/- high-resolution manometry (for at least 90 minutes; 24-hour impedance preferred) is needed to differentiate the two types of belching. 1

Additional GI Considerations:

• Esophagitis/peptic ulcer disease: Burning retrosternal pain related to meals, relieved by antacids, with possible right upper quadrant tenderness. 1, 2

• Carbohydrate intolerance (lactose, fructose, sucrase deficiencies): Can cause bloating and belching; diagnose with 2-week dietary restriction trial first, then breath testing if refractory. 1

• Aerophagia: Consider if manometry shows influx of air into esophagus with swallowing causing intestinal gas accumulation on abdominal X-rays. 1

Musculoskeletal Causes

Costochondritis/Tietze syndrome presents with tenderness of costochondral joints on palpation and pain reproducible with chest wall pressure, localized to a very limited area. 1, 2, 6

• Pain affected by palpation, breathing, turning, twisting, or bending suggests musculoskeletal origin rather than cardiac ischemia. 2, 7

Critical Diagnostic Algorithm

Step 1: Immediate Risk Stratification

• Obtain vital signs, ECG within 10 minutes, and cardiac troponin immediately to exclude ACS, even if symptoms suggest GI etiology. 1, 2
• Perform focused cardiovascular examination to identify complications of ACS, aortic dissection, PE, or esophageal rupture. 1

Step 2: Characterize the Chest Pain

• Left-sided, stabbing, or sharp pain has low probability of ischemia, but pressure, squeezing, heaviness, or exertional pain has high probability. 1
• Pain radiating below the umbilicus or localized to very limited area is unlikely ischemic. 1, 2
• Associated symptoms matter: Diaphoresis, dyspnea, nausea, syncope, or palpitations increase likelihood of ACS. 1

Step 3: Evaluate Belching Pattern

• If excessive belching with reduced quality of life, proceed with ambulatory impedance monitoring to differentiate gastric versus supragastric belching. 1
• Rule out rumination disorder with high-resolution manometry with impedance. 1
• Consider PPI trial if gastric belching related to GERD; consider baclofen if related to excess transient relaxation of lower esophageal sphincter. 1

Step 4: Additional Testing Based on Clinical Suspicion

• Chest radiograph to evaluate for pneumonia (fever, egophony, dullness to percussion), pneumothorax, or other pulmonary/thoracic causes. 1, 6
• Serial ECGs if initial ECG nondiagnostic but clinical suspicion remains high. 1
• Serial troponin at 3-6 hours if initial troponin negative but symptoms persist. 3

Common Pitfalls to Avoid

Do not use nitroglycerin response as a diagnostic criterion, as esophageal spasm and other conditions also respond to nitroglycerin. 1, 2

Do not dismiss chest pain in women or elderly patients (≥75 years), as they frequently present with atypical symptoms including upper abdominal pain, nausea, and shortness of breath rather than classic chest pressure. 1, 2

Do not assume belching automatically means benign GI disease—supragastric belching can cause reflux symptoms including chest pain through SGB-induced gastroesophageal reflux or esophageal distension, and may explain PPI-refractory GERD. 5

Avoid describing chest pain as "atypical", as this term is not helpful and can be misinterpreted as benign; instead describe as cardiac, possibly cardiac, or noncardiac. 1

High-Risk Features Requiring Emergency Department Transfer

• Age ≥75 years with accompanying dyspnea, syncope, acute delirium, or unexplained fall. 1, 2
• ECG abnormalities suggestive of ischemia or new ST-segment changes. 1
• Hemodynamic instability, persistent symptoms, or clinical deterioration. 1
• Elevated cardiac troponin or high clinical suspicion for ACS despite initial negative workup. 1, 3