A 62-year-old woman from Mumbai is admitted with acute inferior wall MI (ST elevation in II, III, aVF) confirmed by ECG and elevated troponin. She is haemodynamically stable (BP 118/76, HR 88). Coronary angiography reveals 100% occlusion of the right coronary artery with TIMI 0 flow. During PCI, the operator achieves TIMI 3 flow. However, 2 hours post-PCI, the patient develops sudden-onset dyspnoea, elevated JVP, clear lung bases, and hypotension (88/54 mmHg). What is the most appropriate next step in management?

Explanation

## Clinical Scenario: Right Ventricular Infarction This patient has developed acute cardiogenic shock in the context of inferior MI with a critical clinical clue: **hypotension with elevated JVP and clear lung bases**. This triad is pathognomonic for **right ventricular (RV) infarction**. ## Diagnostic Features of RV Infarction | Feature | Finding in This Case | Significance | |---------|----------------------|---------------| | **ECG** | ST elevation in II, III, aVF | Inferior MI; RV involvement if ST elevation in V4R | | **Haemodynamics** | Hypotension + elevated JVP + clear lungs | Preserved RV preload but impaired RV contractility | | **Coronary occlusion** | RCA 100% occlusion | RCA supplies RV in 80% of patients | | **Timing** | 2 hours post-PCI | RV dysfunction may be delayed or unmasked after reperfusion | **Key Point:** The combination of hypotension, elevated JVP, and **clear lung bases** (no pulmonary oedema) distinguishes RV infarction from left ventricular failure. In LV failure, elevated JVP would be accompanied by pulmonary crackles. ## Pathophysiology of RV Infarction ```mermaid flowchart TD A[RCA Occlusion]:::outcome --> B[RV Myocardial Necrosis]:::outcome B --> C[Impaired RV Contractility]:::outcome C --> D{Preload Dependence}:::decision D -->|Fluid administration| E[Improved RV Filling + CO]:::action D -->|Diuretics| F[Worsening Shock]:::urgent G[Echocardiography]:::action --> H{RV Dysfunction Confirmed?}:::decision H -->|Yes| I[IV Fluids + Inotropes + Avoid Diuretics]:::action H -->|No| J[Reassess Diagnosis]:::action ``` **High-Yield:** RV infarction is **preload-dependent**. The RV requires adequate venous return to maintain cardiac output. Diuretics worsen shock; fluid resuscitation is the cornerstone of management. ## Why Echocardiography Is Essential 1. **Confirms RV dysfunction** — visualizes RV wall motion abnormality and dilated RV 2. **Assesses LV function** — rules out concurrent LV infarction 3. **Guides fluid vs. inotrope strategy** — if RV is severely dilated, inotropes may be preferred 4. **Detects complications** — RV free wall rupture, tricuspid regurgitation **Clinical Pearl:** Right ventricular infarction occurs in 40–50% of inferior MIs but is often missed. Always obtain **right-sided ECG leads (V4R–V6R)** in inferior MI; ST elevation in V4R has 90% specificity for RV infarction.