Right Ventricular Myocardial Infarction (RVMI)

1. Introduction

Right Ventricular Myocardial Infarction (RVMI) is a distinct clinical entity most commonly occurring in association with inferior wall myocardial infarction.

It is:

• Present in 30–50% of inferior STEMI
• Hemodynamically significant in ~10–15%
• Frequently missed unless actively looked for

The classical triad:

Hypotension + Raised JVP + Clear lung fields

RVMI is preload-dependent shock, and management is fundamentally different from LV infarction.

2. Coronary Anatomy Relevant to RVMI

Blood Supply of Right Ventricle

• Mainly from Right coronary artery
• In ~80–85% individuals → RCA is dominant
• RCA supplies:
• RV free wall
• Inferior LV wall
• AV node (90%)
• SA node (60%)

 Therefore, proximal RCA occlusion → inferior MI + RVMI + AV block

Thus, RVMI = Preload failure, not pump failure

4. Hemodynamic Profile 

Classic finding:

CVP >> PCWP

If CVP > 15 mmHg with hypotension → suspect RVMI.

5. Clinical Presentation

Symptoms

• Acute chest pain (inferior MI pattern)
• Syncope
• Hypotension
• Severe weakness

Signs

• Hypotension
• Elevated JVP
• Clear lung fields
• Kussmaul sign
• Bradycardia (due to AV nodal ischemia)

 Severe cases → Cardiogenic shock

6. ECG Diagnosis (Most Important in )

Step 1: Inferior STEMI

ST elevation in:

• II
• III
• aVF

Step 2: Confirm RV Involvement

Do right-sided leads

Most sensitive lead:V4R

If ST elevation ≥1 mm in V4R → RVMI confirmed

ST elevation in V1 also supports RV involvement.

7. Echocardiography Findings

• Dilated RV
• Hypokinetic RV free wall
• Preserved LV function
• Paradoxical septal motion
• TR may be present

Best bedside tool in ICU.

8. Management of RVMI

A. Immediate Reperfusion (Cornerstone)

• Primary PCI (preferred)
• Thrombolysis if PCI unavailable

Proximal RCA must be opened urgently.

B. Fluid Resuscitation 

RV is preload dependent.

Give:

• 250–500 mL NS bolus
• Repeat guided by BP & JVP

Goal:

• CVP 10–15 mmHg
• SBP > 90 mmHg

 Avoid fluid overload.

C. Drugs to Avoid 

 Nitrates
 Morphine (caution)
 Diuretics
 ACE inhibitors (initially if hypotensive)

These reduce preload → worsen shock.

D. Inotropes (If Fluid Fails)

• Dobutamine (first line)
• Norepinephrine if severe hypotension

Dobutamine:

• Improves RV contractility
• Reduces pulmonary vascular resistance

E. Temporary Pacing

Common in:

• AV block
• Severe bradycardia

Due to RCA supplying AV node.

F. Mechanical Support (Severe Shock)

• IABP (limited benefit in isolated RV failure)
• RV assist device (rare)
• VA-ECMO (refractory shock)

10. Complications

• Complete heart block
• Cardiogenic shock
• Ventricular arrhythmias
• Mechanical complications (rare)
• RV rupture (rare)

11. Prognosis

Isolated RVMI → Good recovery (RV regenerates well)

RV function often improves within:

• Days to weeks after reperfusion

However:

RVMI + LVMI → Mortality increases significantly

12. Differentiating RVMI from Other Causes of Shock