In COPD, which of the following mechanisms is responsible for the development of cor pulmonale?

Explanation

## Cor Pulmonale in COPD: Pathophysiology **Key Point:** Cor pulmonale is right ventricular hypertrophy and eventual failure secondary to chronic lung disease. In COPD, it develops via **chronic hypoxia-induced pulmonary vasoconstriction** → pulmonary hypertension → RV strain. ### Pathological Sequence Leading to Cor Pulmonale ```mermaid flowchart TD A[Chronic hypoxia in COPD]:::outcome --> B[Hypoxic pulmonary vasoconstriction]:::action B --> C[Increased pulmonary vascular resistance]:::outcome C --> D[Pulmonary hypertension]:::outcome D --> E[RV pressure overload]:::action E --> F[RV hypertrophy]:::outcome F --> G{Continued strain?}:::decision G -->|Yes| H[RV dilation & dysfunction]:::urgent G -->|No| I[Compensated state]:::outcome H --> J[Right heart failure - Cor pulmonale]:::urgent ``` ### Key Mechanisms in COPD-Related Cor Pulmonale | Mechanism | Role in COPD | |-----------|-------------| | **Hypoxic vasoconstriction** | PRIMARY driver; mediated by decreased alveolar O₂ tension | | **Loss of capillary bed** | Emphysematous destruction reduces vascular surface area | | **Chronic inflammation** | Endothelial dysfunction, increased vascular stiffness | | **Acidosis & hypercapnia** | Potentiates pulmonary vasoconstriction | **High-Yield:** The sequence is: **Hypoxia → Vasoconstriction → PH → RV strain → Cor pulmonale**. This is the most tested mechanism in NEET PG pathology. **Mnemonic:** **CHOP** = **C**hronic hypoxia → **H**ypertension (pulmonary) → **O**verload (RV) → **P**ulmonale (cor pulmonale). **Clinical Pearl:** Cor pulmonale in COPD typically manifests with peripheral edema, elevated JVP, hepatomegaly, and right-sided S₃ gallop. It is a late-stage complication indicating advanced disease. **Warning:** Do NOT confuse cor pulmonale (RV failure from lung disease) with left heart failure (LV dysfunction from systemic hypertension or CAD). Systemic hypertension alone does NOT cause cor pulmonale. [cite:Robbins 10e Ch 15]