What is the immediate management for a patient suspected of having a right ventricular myocardial infarction (MI)?

Immediate Management of Right Ventricular Myocardial Infarction

For suspected right ventricular MI, immediately obtain a 12-lead ECG including right-sided precordial leads (V3R-V4R) within 10 minutes, administer aspirin 160-325 mg, avoid nitrates and diuretics, and aggressively volume resuscitate with intravenous normal saline while preparing for urgent reperfusion therapy. 1, 2, 3

Initial Recognition and Diagnosis

Clinical presentation: Suspect RV MI when you see the triad of hypotension, elevated jugular venous pressure, and clear lung fields in the setting of inferior wall STEMI 3, 4, 5. This occurs in approximately 25-50% of inferior wall MIs and defines a high-risk subgroup with significantly worse prognosis 3, 5.

ECG findings to identify:

• ST-segment elevation in lead III greater than in leads II or aVF 5
• ST-segment elevation ≥1 mm in lead V1 5
• Most importantly: ST-segment elevation ≥1 mm in right precordial leads V3R-V4R (must be obtained early as this finding may resolve within hours) 3, 5
• Obtain the 12-lead ECG within 10 minutes of arrival 1, 2

Confirm with bedside echocardiography to assess RV dysfunction and elevated right-sided filling pressures disproportionate to left-sided pressures, but do not delay reperfusion therapy 2, 3.

Critical Hemodynamic Management

Volume resuscitation is the cornerstone of RV MI management:

• Aggressively administer intravenous normal saline boluses (typically 1-2 liters initially) to maintain adequate RV preload 3, 4
• RV filling pressures are entirely dependent on preload; the failing RV cannot generate adequate cardiac output without sufficient volume 3, 5
• Monitor response to fluid administration and titrate accordingly 4

Absolute contraindications in RV MI:

• Do NOT give nitrates (sublingual or intravenous) as they reduce preload and can cause profound, life-threatening hypotension 2, 3
• Avoid diuretics which will worsen hemodynamics by reducing preload 3
• Use morphine cautiously as it may cause hypotension through vasodilation 2, 3

Immediate Pharmacological Interventions

Administer immediately:

• Aspirin 160-325 mg orally (chewed for faster absorption) 1, 2
• P2Y12 inhibitor (ticagrelor or prasugrel preferred over clopidogrel) 2
• Oxygen only if SaO₂ <90% or PaO₂ <60 mmHg (routine oxygen is harmful) 2

Maintain atrioventricular synchrony:

• RV filling is critically dependent on atrial contraction 3, 4
• For symptomatic bradycardia, give atropine 0.5-1.0 mg IV (may repeat up to 3 mg total) 2
• Have transcutaneous pacing immediately available 2
• Promptly cardiovert atrial fibrillation or flutter to restore AV synchrony 3

Urgent Reperfusion Strategy

Early reperfusion is essential and improves both short- and long-term outcomes:

• Primary PCI is strongly preferred if available within 90 minutes of first medical contact 1, 2, 4
• Fibrinolytic therapy if PCI cannot be performed within 120 minutes (door-to-needle time ≤30 minutes) 1, 3
• The RV has greater potential for recovery from ischemia compared to the LV, making timely reperfusion particularly beneficial 4
• Maximum benefit occurs within the first hour ("golden hour") with progressively diminishing benefit thereafter 1

Management of Cardiogenic Shock

If hypotension persists despite adequate volume loading:

• Consider inotropic support with dobutamine to support RV contractility 3, 4
• Vasopressors (norepinephrine) may be needed to maintain adequate perfusion pressure 4
• Reduce RV afterload, particularly when concomitant LV dysfunction is present 3, 4
• Timely mechanical circulatory support should be considered in eligible patients with refractory cardiogenic shock 4

Common Pitfalls to Avoid

• Never administer nitrates or diuretics in suspected RV MI—this can cause catastrophic hypotension 2, 3
• Do not delay reperfusion therapy waiting for cardiac biomarkers when ECG shows ST-elevation 1, 2
• Do not give beta-blockers or calcium channel blockers in the acute phase as they may worsen bradycardia and conduction abnormalities 2
• Do not miss the diagnosis by failing to obtain right-sided precordial leads (V3R-V4R) early, as ST-elevation in these leads may resolve within hours 3, 5
• Avoid excessive fluid administration if there is no RV involvement, as this worsens LV failure 2

Monitoring and Ongoing Care

• Continuous cardiac monitoring for life-threatening arrhythmias and conduction disturbances 1, 2
• RV MI is associated with high rates of in-hospital morbidity and mortality from hemodynamic compromise and electrical complications 6
• Most survivors experience restoration of normal RV function with resolution of hemodynamic abnormalities over time 3, 4