What is right ventricular hypertrophy (RVH)?

Right Ventricular Hypertrophy: Definition and Clinical Significance

Right ventricular hypertrophy (RVH) is an increase in the mass and thickness of the right ventricular myocardium that occurs in response to increased workload on the right ventricle, causing a displacement of the QRS vector toward the right and anteriorly on electrocardiogram. 1

Pathophysiologic Mechanism

RVH develops when conditions impose increased pressure or volume loads on the right ventricle, requiring the myocardium to thicken in compensation. 1 The structural changes include:

• Increased right ventricular wall thickness beyond normal values (>3.1 mm/m² in men, >3.0 mm/m² in women when indexed to body surface area) 2
• Increased right ventricular mass that can be detected by echocardiography or cardiac MRI 3
• Delay in R-wave peak time in right precordial leads reflecting delayed right ventricular activation 1

Common Etiologies

The underlying causes vary significantly and affect diagnostic accuracy:

• Congenital heart disease (highest ECG diagnostic accuracy) 1
• Acquired valvular heart disease (intermediate accuracy) 1
• Primary pulmonary hypertension (intermediate accuracy) 1
• Chronic lung disease including COPD (lowest ECG diagnostic accuracy) 1
• Systemic hypertension with biventricular involvement (prevalence 17-80% in hypertensive populations, averaging 28.6%) 4

ECG Patterns: Pressure vs. Volume Overload

RVH manifests in two distinct electrocardiographic patterns based on the type of hemodynamic stress: 1, 5

Pressure Overload Pattern

• Predominantly tall R waves in right precordial leads (Rs, R, or Qr complexes in V1) 1, 5
• Right axis deviation (>90 degrees) 1
• ST depression and T-wave inversion in right precordial leads (termed "secondary ST-T abnormality" rather than "strain") 1

Volume Overload Pattern

• Resembles incomplete right bundle branch block 1
• Right axis deviation 1, 5
• Secondary ST-T abnormalities in right precordial leads 1, 5

Critical Diagnostic Limitations

The ECG has notoriously low sensitivity (27-43%) for detecting RVH because considerable degrees of hypertrophy are required to overcome the normal dominance of left ventricular forces. 1, 6 However, certain criteria maintain high specificity and clinical utility. 1

Required ECG Findings

• Right axis deviation and prominent anterior forces in right precordial leads should be required for diagnosis in nearly all cases 1, 6
• Increased R-wave amplitude in V1 is particularly important, especially in patients with COPD 1, 5

Context-Dependent Accuracy

The diagnostic performance varies dramatically: 1, 6

• Greatest accuracy: Congenital heart disease
• Intermediate accuracy: Acquired heart disease and primary pulmonary hypertension
• Lowest accuracy: Chronic lung disease

Clinical Significance and Prognostic Impact

RVH carries significant prognostic implications beyond simple anatomic change:

• More than doubles the risk of heart failure or cardiovascular death in population-based studies (hazard ratio 2.52,95% CI 1.55-4.10) 3
• Associated with biventricular hypertrophy in approximately 17.8% of hypertensive patients, indicating very high cardiovascular risk 2
• Causes impairment of left ventricular diastolic function through ventricular interdependence and increased collagen content in both ventricles 7
• Commonly accompanies left ventricular pressure overload (present in 80% of hypertensive patients and 63% of aortic stenosis patients) even without pulmonary hypertension 8

Biventricular Hypertrophy Recognition

When ECG criteria for left ventricular hypertrophy are present, suspect concurrent RVH if: 1

• Prominent S waves in V5 or V6 are present
• Right axis deviation persists despite LVH
• Unusually tall biphasic R/S complexes appear in several leads
• Signs of right atrial abnormality are evident

Note that biventricular hypertrophy has particularly low ECG sensitivity due to cancellation of opposing QRS vectors from both ventricles. 1

Pediatric Considerations

Age-specific criteria must be applied in children as normal R-wave amplitude in V1 and S-wave amplitude in V6 vary significantly with age. 1 For children ≥5 years, RVH is suggested by: 1

• RV1 ≥13 mm
• SV6 ≥4 mm
• RV1 + SV6 ≥17 mm

Interpretation Recommendations

No single ECG criterion should be used exclusively; multiple criteria improve diagnostic accuracy. 1, 6 The American College of Cardiology recommends: 1

• Adjust criteria for age, gender, race, and body habitus when validated adjustments exist
• Incorporate clinical context including diagnoses suggesting congenital heart disease, valvular disease, or chronic pulmonary disease
• Avoid the term "strain" in favor of "secondary ST-T abnormality"
• Recognize that many ECG findings can occur as normal variants, making clinical correlation essential 1, 5