What is the management for a patient with ST elevation in lead V2 only, suspected of having acute coronary syndrome or myocardial infarction (MI)?

Management of ST Elevation in Lead V2 Only

Isolated ST elevation in V2 requires immediate assessment to determine if this represents true STEMI (meeting voltage criteria and clinical context), early hyperacute changes, right ventricular infarction, or a normal variant—with the critical first step being verification of voltage thresholds and obtaining additional ECG leads. 1

Immediate Diagnostic Assessment

Verify STEMI Voltage Criteria

• Check if ST elevation in V2 meets diagnostic thresholds: ≥2.0 mm (0.2 mV) in men over 40 years, ≥2.5 mm in men under 40 years, or ≥1.5 mm (0.15 mV) in women 1
• If voltage criteria are NOT met, this does not qualify as STEMI by standard definition and requires alternative diagnostic approach 1

Obtain Additional ECG Leads Immediately

• Record right-sided precordial leads (V3R, V4R) to identify right ventricular infarction, which can present with isolated ST elevation in V1-V2 and occurs in 40-50% of inferior MIs 2, 3
• Obtain posterior leads (V7-V9) to detect posterior wall involvement that may manifest as isolated anterior changes 1
• Compare with any prior ECG if available—this is critically important to determine if findings are new or chronic 1, 4

Repeat ECG Monitoring

• Perform serial ECGs every 5-10 minutes if initial tracing is equivocal, as some patients present very early and may show hyperacute T waves that precede ST elevation 1
• Initiate continuous ST-segment monitoring to detect evolving changes 1

Clinical Context Assessment

Evaluate for Ongoing Myocardial Ischemia

• Assess for typical ischemic symptoms: substernal chest discomfort radiating to arms or jaw, associated with diaphoresis, nausea, or dyspnea 5
• Chest pain reproducible with palpation or varying with breathing/position makes ACS less likely 5
• If persistent ischemic symptoms are present despite non-diagnostic ECG, this mandates emergency coronary angiography regardless of ST elevation criteria 1

Obtain Cardiac Biomarkers

• Draw high-sensitivity troponin immediately, but do NOT wait for results to initiate reperfusion therapy if STEMI criteria are met 1, 5
• Repeat troponin at 6-12 hours if initial presentation is equivocal 1
• A positive point-of-care troponin 1-2 hours after symptom onset helps decide on emergency angiography 1

Management Algorithm Based on Findings

If STEMI Criteria ARE Met (voltage thresholds exceeded + ischemic symptoms):

Activate cardiac catheterization lab immediately for primary PCI 2, 6, 5

• Target door-to-balloon time <90 minutes from first medical contact 2
• If PCI cannot be performed within 120 minutes, administer fibrinolytic therapy 2, 6

Initiate immediate medical therapy:

• Aspirin 160-325 mg (non-enteric coated, chewed) unless contraindicated 2, 6
• Dual antiplatelet therapy with clopidogrel, ticagrelor, or prasugrel 6, 5
• Parenteral anticoagulation (unfractionated heparin, LMWH, bivalirudin, or fondaparinux) 6, 7
• Sublingual nitroglycerin for chest pain 2
• Oxygen only if SaO2 <90% 2
• IV morphine for pain relief (titrated doses) 2

If Right Ventricular Infarction is Identified (ST elevation ≥0.5 mm in V3R/V4R):

Management differs fundamentally from standard MI: 2, 3

• Aggressively administer IV fluids: rapid boluses of 500-1000 mL normal saline to maintain RV preload 2
• Strictly avoid ALL vasodilators: no nitrates, no morphine, no diuretics, no ACE-inhibitors—these cause catastrophic hypotension 2
• Immediately cardiovert atrial fibrillation to restore atrial contribution to RV filling 2
• Institute dual-chamber pacing immediately if any heart block develops 2
• Proceed with primary PCI or fibrinolysis as for standard STEMI 2

If STEMI Criteria Are NOT Met but Ischemic Symptoms Persist:

Treat as non-ST elevation ACS: 1

• Administer aspirin, clopidogrel, LMWH or unfractionated heparin, beta-blocker, and nitrates for persistent chest pain 1
• Proceed to emergency coronary angiography with view to revascularization—ongoing ischemia despite medical therapy is an absolute indication even without diagnostic ST elevation 1
• This approach prevents denial of reperfusion therapy to patients with genuine acute coronary occlusion (such as circumflex artery occlusion) who may not show classic ST elevation 1

If No Ischemic Symptoms and Voltage Criteria Not Met:

Consider alternative diagnoses and outpatient evaluation 4

• Obtain echocardiography to assess for structural abnormalities, wall motion abnormalities, or cardiomyopathy 1, 4
• Arrange stress testing to investigate underlying coronary artery disease if risk factors present 1, 4

Critical Pitfalls to Avoid

• Failing to obtain right-sided leads misses RV involvement in cases that may present with isolated V1-V2 elevation, leading to inappropriate vasodilator use and cardiovascular collapse 2, 3
• Treating RV infarction with standard protocols (nitrates, diuretics) causes catastrophic hypotension—instead give aggressive IV fluids 2
• Dismissing isolated V2 elevation as "not meeting criteria" when patient has ongoing ischemic symptoms—these patients require emergency angiography regardless of ECG findings 1
• Waiting for troponin results before activating catheterization lab when STEMI criteria are met clinically and electrocardiographically 1
• Ignoring the possibility of early presentation with hyperacute T waves that precede ST elevation—repeat ECG frequently 1