How should I treat a patient presenting with chest pain, hypertension, incomplete right bundle branch block (RBBB), possible left ventricular hypertrophy (LVH), ST deviation, and moderate T wave abnormality with flat troponins (trops)?

Management of Chest Pain with ECG Abnormalities and Flat Troponins

The patient with chest pain, hypertension, incomplete RBBB, possible LVH, ST deviation, and T wave abnormalities with flat troponins should be admitted to a cardiac monitoring unit and treated as a high-risk non-ST-elevation acute coronary syndrome (NSTE-ACS) with serial ECGs, repeated troponin measurements, and early invasive strategy consideration. 1

Initial Assessment and Management

1. Immediate Interventions:

   • Administer aspirin 325mg chewed (or 75-150mg daily) 1
   • Provide supplemental oxygen if SaO₂ < 90% 1
   • Consider IV opioids (4-8mg morphine with additional 2mg at 5-15 min intervals) for pain relief 1
   • Control hypertension with IV beta-blockers (metoprolol 5mg IV bolus, can be repeated twice at 5-minute intervals if tolerated) 2

2. ECG Evaluation:

   • Obtain serial ECGs at 15-30 minute intervals during the first hour, especially if symptoms persist 1
   • Consider additional posterior leads (V7-V9) to rule out posterior MI, as RBBB can mask ischemic changes 1, 3
   • Evaluate for ST-segment changes that may indicate ongoing ischemia despite RBBB 3

3. Laboratory Assessment:

   • Obtain serial cardiac troponin measurements at presentation and 3-6 hours after symptom onset 1
   • Additional troponin measurements beyond 6 hours if initial values are normal but clinical suspicion remains high 1

Risk Stratification

This patient has several high-risk features:

• Hypertension (BP 140/120)
• ECG abnormalities (incomplete RBBB, possible LVH, ST deviation, T wave abnormalities)
• Ongoing chest pain

Even with flat troponins, these features warrant treatment as a high-risk NSTE-ACS 1:

1. Medical Therapy:

   • Continue aspirin 75-150mg daily
   • Add clopidogrel (loading dose 300-600mg, then 75mg daily)
   • Start low molecular weight heparin (LMWH) or unfractionated heparin
   • Continue beta-blockers (oral metoprolol 25-50mg every 6 hours, transitioning to 100mg twice daily) 2
   • Add oral or IV nitrates for persistent or recurrent chest pain 1

2. Monitoring:

   • Continuous cardiac monitoring for arrhythmias
   • Monitor for signs of hemodynamic instability (hypotension, pulmonary rales)
   • Repeat ECGs with any recurrence of chest pain 1

Further Diagnostic Evaluation

1. Imaging:

   • Obtain chest radiograph to evaluate for other potential cardiac, pulmonary, and thoracic causes 1
   • Consider echocardiography to assess left ventricular function and regional wall motion abnormalities 1

2. Special Considerations for RBBB and LVH:

   • RBBB can mask ischemic changes, making diagnosis more challenging 3, 4
   • LVH can cause various ST-T abnormalities that may mimic ischemia 5
   • In patients with RBBB and chest pain, look for tall R waves, upright T waves, and marked ST depression >2mm in V1-V3, which may indicate posterior ischemia 4

Definitive Management Strategy

Based on risk assessment:

1. High-Risk Features (any of the following):

   • Recurrent chest pain or dynamic ST changes
   • Hemodynamic instability
   • Major arrhythmias
   • Diabetes mellitus

   Management: Early invasive strategy with coronary angiography within 24-48 hours 1

2. If No High-Risk Features:

   • Continue medical therapy
   • Consider non-invasive stress testing or coronary CT angiography after serial troponins are negative 1, 6

Common Pitfalls to Avoid

1. Do not dismiss ECG abnormalities due to RBBB or LVH

   • RBBB patients historically received less aggressive treatment despite similar or worse outcomes compared to LBBB 3
   • Up to 6% of patients with evolving ACS are discharged with a normal ECG 1

2. Do not rely solely on a single troponin measurement

   • Serial measurements are essential, especially with concerning ECG findings 1

3. Do not delay treatment based on flat troponins alone

   • The combination of chest pain, hypertension, and ECG abnormalities warrants aggressive management even with initially negative troponins 1

4. Do not overlook posterior MI

   • Consider posterior leads (V7-V9) when standard ECG shows ST depression in anterior leads, especially with RBBB 1, 4