What is the next step in managing a patient with atrial fibrillation (AF) presenting with severe chest pain, negative troponin test, and no response to pantoprazole (proton pump inhibitor)?

Management of Chest Pain in a Patient with Atrial Fibrillation and Negative Troponin

The next step in managing this patient with atrial fibrillation presenting with severe chest pain, negative troponin, and no response to pantoprazole should be to perform a cardiac evaluation including coronary CT angiography or stress testing to rule out coronary artery disease as the cause of chest pain.

Initial Assessment

When evaluating a patient with known atrial fibrillation presenting with severe chest pain, several important considerations must be addressed:

• The negative troponin T suggests absence of myocardial necrosis, but doesn't rule out unstable angina
• Lack of response to pantoprazole indicates the pain is unlikely to be of gastroesophageal origin
• Atrial fibrillation itself can cause chest pain through various mechanisms, but other serious causes must be excluded

Diagnostic Approach

Immediate Investigations:

1. 12-lead ECG - To assess for dynamic ST-segment changes, which may indicate ischemia despite negative troponin 1
2. Serial troponin measurements - A single negative troponin doesn't exclude ACS; repeat after 6-12 hours 1
3. Continuous ECG monitoring - To detect any dynamic changes during episodes of chest pain 1

Additional Testing:

• Echocardiogram - To assess left ventricular function, valvular disease, and wall motion abnormalities 1
• Coronary evaluation - Either through:
  • Coronary CT angiography - Particularly useful in intermediate-risk patients 2
  • Stress testing - To evaluate for inducible ischemia

Management Algorithm

1. Rate control assessment:

   • Ensure adequate rate control of AF using beta-blockers or non-dihydropyridine calcium channel blockers 1, 3
   • Target heart rate <110 bpm at rest 3
   • Consider IV beta-blockers (metoprolol 2.5-5.0 mg) or calcium channel blockers (diltiazem 15-25 mg) if rate is poorly controlled 3

2. Rule out coronary artery disease:

   • If ECG shows dynamic changes or patient has ongoing pain, proceed with coronary evaluation
   • Consider coronary CT angiography as a non-invasive option 2
   • For higher-risk patients, consider invasive coronary angiography

3. Consider alternative diagnoses:

   • Pulmonary embolism
   • Aortic dissection
   • Stress-induced cardiomyopathy
   • Myocarditis

Important Considerations

• Troponin elevation can occur in AF without coronary atherosclerosis due to myocardial strain from rapid ventricular rates 4, 5, but a negative troponin doesn't exclude unstable angina
• AF with rapid ventricular response can cause supply-demand mismatch leading to chest pain even without fixed coronary stenosis
• Patients with AF have increased risk of coronary events, so thorough evaluation is warranted

Pitfalls to Avoid

• Don't assume gastroesophageal reflux disease is the cause of chest pain based solely on lack of troponin elevation
• Don't stop at a single negative troponin - serial measurements are recommended to rule out ACS 1
• Don't attribute chest pain solely to AF without excluding other serious causes
• Don't delay anticoagulation assessment - ensure appropriate stroke prevention therapy is in place based on CHA₂DS₂-VASc score 3

By following this approach, you can systematically evaluate and manage a patient with AF presenting with chest pain, ensuring that potentially life-threatening causes are not missed while providing appropriate treatment for symptom relief.