What is the management for a patient with acute coronary syndrome (ACS) presenting with chest pain radiating to the right arm?

Management of ACS with Chest Pain Radiating to the Right Arm

Radiation of chest pain to the right arm is a significant clinical finding that increases the likelihood of acute coronary syndrome and should prompt immediate activation of the ACS protocol with the same urgency as left arm radiation. 1

Clinical Significance of Right Arm Radiation

• Right arm radiation increases the likelihood of ACS by nearly 3-fold (likelihood ratio 2.9,95% CI 1.4-6.3), making it as clinically important as traditional left arm radiation 1
• Typical ACS pain is described as pressure, oppression, or heaviness that is retrosternal and may radiate to the left arm, right arm, both arms, neck, jaw, or back 2
• The presence of diaphoresis combined with typical pain patterns (including right arm radiation) has 95% specificity and a likelihood ratio of 5.18 for ACS 2

Immediate Actions (Within 10 Minutes)

Call 9-1-1 immediately and transport by ambulance rather than private vehicle for any patient with chest pain radiating to the right arm lasting more than 5 minutes 3

Prehospital Management

• EMS providers should administer 162-325 mg aspirin (chewed, non-enteric coated) unless contraindicated or already taken 3
• Administer 1 dose of sublingual nitroglycerin if previously prescribed; if pain is unimproved or worsening after 5 minutes, call 9-1-1 before additional doses 3
• For chronic stable angina with improvement after first dose, may repeat nitroglycerin every 5 minutes for maximum 3 doses, calling 9-1-1 if symptoms not completely resolved 3

Emergency Department Triage (Immediate Assessment Required)

• Obtain 12-lead ECG within 10 minutes of presentation to distinguish STEMI from non-ST-elevation ACS 3, 2, 4
• Draw cardiac troponin immediately (preferably high-sensitivity troponin I or T) with repeat measurement at appropriate intervals per protocol 3, 2
• Patients with chest pain radiating to the right arm require immediate triage nurse assessment for ACS protocol initiation 3

Risk Stratification Based on Presentation

High-Risk Features (Immediate ED Referral)

Patients with right arm radiation plus any of the following require immediate ED transport 3:

• Chest discomfort at rest for >20 minutes
• Hemodynamic instability
• Recent syncope or presyncope
• Severe dyspnea
• Palpitations

Intermediate-Risk Features

Right arm radiation in patients who are male, age >70 years, or diabetic increases ACS likelihood 3, 1

Diagnostic Evaluation

ECG Interpretation

• STEMI: Persistent ST-segment elevation >1 mm in contiguous leads or new left bundle branch block 3, 2
• NSTE-ACS: ST-segment depression (31%), T-wave inversions (12%), both (16%), or neither (41%) 4
• New or transient ST-segment deviation ≥1 mm or T-wave inversion in multiple precordial leads indicates high likelihood of ACS 3

Cardiac Biomarkers

• Elevated troponin I, troponin T (>99th percentile upper reference limit) with rising or falling pattern confirms myocardial infarction 3
• Troponin measurement at 0 and 1-2 hours using ESC algorithms for rapid rule-in/rule-out 3
• Repeat troponin at least 6 hours apart if initial measurements non-diagnostic 3

Additional Imaging

• Chest radiograph to evaluate for mediastinal widening (aortic dissection), pneumothorax, or pneumonia 2
• Contrast-enhanced chest CT if aortic dissection or pulmonary embolism suspected based on clinical features 2

Acute Medical Management

Antiplatelet Therapy

• Aspirin 162-325 mg orally immediately (chewed for faster absorption) unless contraindicated 3, 5
• Add second antiplatelet agent (clopidogrel 300 mg loading dose then 75 mg daily, or ticagrelor, or prasugrel) for dual antiplatelet therapy 6, 5

Anticoagulation

• Initiate parenteral anticoagulation with unfractionated heparin, low-molecular-weight heparin, bivalirudin, or fondaparinux 5

Anti-Ischemic Therapy

• Sublingual nitroglycerin (up to 3 doses, 5 minutes apart) unless systolic BP <90 mmHg 3, 5
• Intravenous nitroglycerin for ongoing chest pain or ST-segment changes 5
• Beta-blockers unless contraindicated 5
• Morphine for pain relief if nitroglycerin insufficient 5

Additional Therapies

• Statins initiated early 5
• ACE inhibitors 5
• Proton pump inhibitors for patients at higher risk of GI bleeding on dual antiplatelet therapy 5

Reperfusion Strategy

STEMI (ST-Elevation on ECG)

• Primary PCI within 120 minutes of first medical contact reduces mortality from 9% to 7% 4
• If PCI cannot be achieved within 120 minutes: fibrinolytic therapy (alteplase, reteplase, or tenecteplase at full dose for age <75 years; half dose for age ≥75 years), followed by transfer for PCI within 24 hours 4

NSTE-ACS (No Persistent ST-Elevation)

• High-risk patients: Invasive coronary angiography with percutaneous or surgical revascularization within 24-48 hours reduces mortality from 6.5% to 4.9% 4
• The CURE trial demonstrated 20% relative risk reduction (p<0.001) with clopidogrel plus aspirin versus aspirin alone in NSTE-ACS 6

Critical Pitfalls to Avoid

• Do not dismiss right arm radiation as atypical—it carries nearly 3-fold increased likelihood of ACS and warrants full evaluation 1
• Do not evaluate patients with suspected ACS solely over the telephone—they require facility-based evaluation with ECG and biomarkers 3
• Do not delay ECG beyond 10 minutes of presentation 3, 2, 4
• Do not wait for troponin results before initiating reperfusion therapy in STEMI—ECG findings alone warrant immediate treatment 4
• Women, elderly patients (≥75 years), and diabetics more frequently present with atypical symptoms including isolated right arm pain without chest discomfort 3, 1
• Approximately 40% of men and 48% of women with ACS present with nonspecific symptoms rather than typical chest pain 4