A 52-year-old man with chronic hypertension for 15 years presents with dyspnea on exertion. Echocardiography reveals concentric left ventricular hypertrophy with normal chamber size. What is the most common cause of cardiac hypertrophy in this patient?

Explanation

## Most Common Cause of Cardiac Hypertrophy **Key Point:** Chronic systemic hypertension is the single most common cause of left ventricular hypertrophy (LVH) in clinical practice, accounting for >90% of cases in the general population. ### Pathophysiology of Hypertension-Induced LVH 1. **Chronic pressure overload** → sustained increase in wall stress 2. **Compensatory hypertrophy** → individual myocyte enlargement (concentric pattern) 3. **Preserved chamber size** → maintains ejection fraction initially 4. **Progressive fibrosis** → diastolic dysfunction develops ### Differential Causes of Cardiac Hypertrophy | Cause | Pattern | Chamber Size | Prevalence | |-------|---------|--------------|------------| | **Systemic hypertension** | Concentric | Normal | Most common | | Aortic stenosis | Concentric | Normal | Common valve lesion | | Hypertrophic cardiomyopathy | Asymmetric septal | Normal/↓ | Genetic; <1% population | | Thyrotoxicosis | Eccentric | Dilated | Rare; high-output state | | Athlete's heart | Eccentric | Dilated | Physiologic adaptation | **Clinical Pearl:** The distinction between pathologic LVH (hypertension) and physiologic LVH (athlete's heart) is made by regression of hypertrophy after cessation of stimulus and absence of diastolic dysfunction in athletes. **High-Yield:** In India, hypertension prevalence is rising; LVH is the most frequent cardiac adaptation seen on echocardiography in hypertensive patients. ### Why Concentric Pattern? Concentric hypertrophy occurs because: - Pressure overload (not volume overload) triggers the response - Wall thickness increases relative to chamber diameter - Maintains systolic function but impairs diastolic relaxation [cite:Robbins 10e Ch 1]