ECG Changes in Right Ventricular Hypertrophy (RVH)
Right ventricular hypertrophy (RVH) causes characteristic ECG changes including right axis deviation and prominent anterior forces in the right precordial leads, though the sensitivity of ECG for detecting RVH is generally low while specificity can be high. 1
Primary ECG Findings in RVH
QRS Axis and Amplitude Changes
- Right axis deviation (typically >90° in adults)
- Prominent R waves in right precordial leads (V1, V2)
- R/S ratio >1 in lead V1 (normally S wave is dominant in V1)
- Persistent S waves across precordial leads (V1-V6)
- Deep S waves in left lateral leads (I, aVL, V5, V6)
ST-T Wave Changes
- ST depression and T-wave inversion in right precordial leads (V1-V3)
- These ST-T abnormalities are better referred to as "secondary ST-T abnormality" rather than "strain" 1
P Wave Changes
- P pulmonale pattern (tall, peaked P waves in leads II, III, aVF)
- Rightward P-wave axis (>60°)
- These changes suggest right atrial abnormality often accompanying RVH 1
Pattern Classification
RVH typically manifests in two distinct patterns, particularly in congenital heart disease 1:
Volume Overload Pattern:
- Similar to incomplete RBBB
- rSR' pattern in V1
- Associated with conditions like atrial septal defect
Pressure Overload Pattern:
- Predominantly tall R waves in right precordial leads (Rs, R, or Qr complexes)
- More common in pulmonary hypertension
- qR pattern in V1 is strongly associated with right ventricular systolic dysfunction 2
Both patterns are typically associated with right axis deviation.
Specific ECG Criteria for RVH
Several validated criteria exist, with varying sensitivity and specificity 1:
- R wave in V1 > 6 mm
- R/S ratio in V1 > 1.0
- qR pattern in V1
- R wave in V1 + S wave in V5 or V6 > 10.5 mm
- Right axis deviation > +90°
- S wave in lead I > 5 mm 3
Special Considerations
Chronic Obstructive Pulmonary Disease (COPD)
COPD produces a characteristic ECG pattern reflecting the low diaphragm position 1:
- Low voltage in limb leads
- Rightward, superior, or indeterminate QRS axis
- Rightward P-wave axis (>60°)
- Persistent S waves across all precordial leads
- Low R-wave amplitude in V6
In COPD, RVH is suggested only if R-wave amplitude in V1 is relatively increased despite these other changes.
Pediatric Considerations
Age-specific criteria are essential for diagnosing RVH in children, as normal values change significantly with age 1:
| Age | RV1 (mm) | SV6 (mm) | RV1+SV6 (mm) |
|---|---|---|---|
| 0-7 days | 27 | 10 | 37 |
| 7d-1y | 22 | 10 | 43 |
| 1-3y | 18 | 7 | 30 |
| 3-5y | 18 | 6 | 24 |
| >5y | 13 | 4 | 17 |
Diagnostic Challenges
- ECG has limited sensitivity (approximately 27-31%) for detecting RVH compared to echocardiography or autopsy findings 4
- Specificity is generally better (85-88%) 4
- Vector changes in the horizontal plane can help differentiate RVH from posterobasal LVH when both show deep S waves in V5-V6 3
- Biventricular hypertrophy can mask RVH due to cancellation of opposing electrical forces 1
Clinical Correlation
The American College of Cardiology recommends 5:
- Using ancillary clinical information when interpreting ECG for RVH
- Adjusting probability estimates based on clinical diagnoses suggesting congenital heart disease, valvular heart disease, or chronic pulmonary disease
- Considering echocardiography for definitive diagnosis, as ECG has limited sensitivity (73%) for detecting pulmonary hypertension
Pitfalls to Avoid
- Relying solely on ECG for ruling out RVH (low sensitivity)
- Failing to consider age-appropriate criteria in pediatric patients
- Not recognizing that biventricular hypertrophy may mask typical RVH patterns
- Overlooking RVH in the presence of COPD pattern without evaluating R wave amplitude in V1
- Misinterpreting normal variant patterns as RVH (false positives)
Remember that right axis deviation and prominent anterior forces should be required for diagnosing RVH in nearly all cases, but these features can occur for reasons other than RVH, including as normal variants 1.