Is left ventricular hypertrophy (LVH) the same as left ventricular dilatation?

No, Left Ventricular Hypertrophy and Left Ventricular Dilatation Are Distinct Pathophysiologic Entities

Left ventricular hypertrophy (LVH) and left ventricular dilatation (LVD) represent fundamentally different cardiac remodeling patterns that can occur independently or coexist, but they are not the same condition. 1

Key Structural Differences

Left Ventricular Hypertrophy

• LVH involves increased left ventricular wall thickness and/or increased left ventricular mass 1
• Results primarily from pressure overload conditions (hypertension, aortic stenosis) 2
• The myocardium thickens in response to chronic increased afterload 2

Left Ventricular Dilatation

• LVD involves increased left ventricular chamber size (increased end-diastolic volume) 1
• Results primarily from volume overload conditions (valvular regurgitation, high-output states) 2
• The chamber expands to accommodate increased preload 2

Classification of LV Geometry Patterns

The 2019 ACC/AHA/ASE guidelines define distinct geometric patterns based on whether hypertrophy and/or dilatation are present 1:

Normal Geometry

• Normal wall thickness and normal chamber size 1

Concentric Hypertrophy

• Increased wall thickness with normal or reduced chamber size 1
• Increased LV mass with normal or low end-diastolic volume 3
• Typical of chronic hypertension 2

Eccentric Hypertrophy

• Both increased chamber size AND increased LV mass present 1
• Represents combined volume overload and compensatory hypertrophy 4

Eccentric Remodeling

• Increased chamber size but normal LV mass 1
• Pure dilatation without hypertrophic response 1

Concentric Remodeling

• Increased wall thickness but normal LV mass 1
• Increased relative wall thickness without true hypertrophy 1

Clinical Significance of the Distinction

The differentiation between LVH and LVD has critical prognostic implications 4, 3:

• Eccentric dilated hypertrophy (both increased mass and volume) carries the highest risk for cardiovascular mortality and heart failure 3
• Eccentric nondilated hypertrophy (increased mass without dilatation) represents a low-risk subset with similar outcomes to patients with normal LV mass 3
• LV dilatation independently predicts heart failure development, even when accounting for other risk factors 4
• Concentric hypertrophy (increased mass without dilatation) has intermediate risk 3

Functional Differences

Hypertrophy Without Dilatation

• Typically maintains or increases ejection fraction (hyperdynamic function) 1
• May develop diastolic dysfunction with preserved systolic function 1
• Associated with increased myocardial work efficiency initially 5

Dilatation With or Without Hypertrophy

• Often associated with reduced ejection fraction 1
• Represents more advanced remodeling when combined with hypertrophy 1
• Associated with increased wasted myocardial work and reduced work efficiency 5

Diagnostic Approach

Echocardiography is the primary modality to distinguish these entities 1:

• Measure LV wall thickness (interventricular septum and posterior wall) 1
• Calculate LV mass indexed to body surface area 1
• Measure LV end-diastolic volume indexed to body surface area 1
• Calculate relative wall thickness (2 × posterior wall thickness / LV internal dimension) 1
• Determine LV geometry pattern based on these measurements 1

ECG has limited ability to distinguish LVH from LVD 6:

• Increased QRS voltage suggests LVH but cannot differentiate concentric from eccentric patterns 1
• Horizontal plane QRS vector magnitude cannot reliably differentiate concentric LVH from isolated LVD 6

Common Pitfall

The most critical error is assuming that all LV enlargement represents the same pathophysiology. The presence or absence of chamber dilatation in addition to increased mass fundamentally changes risk stratification and may influence management decisions 4, 3. Always obtain complete geometric assessment including both wall thickness/mass AND chamber volume measurements 1.