From the Guidelines
The criteria for diagnosing Right Ventricular Hypertrophy (RVH) on an electrocardiogram (ECG) include a dominant R wave in lead V1, right axis deviation, and deep S waves in leads I, aVL, and V6, as stated in the 2009 American Heart Association recommendations 1.
Key Findings
The most important criteria for RVH diagnosis are:
- A dominant R wave in lead V1 (R wave amplitude greater than S wave)
- Right axis deviation (typically greater than +90 degrees)
- Deep S waves in leads I, aVL, and V6 Additional findings may include:
- An R/S ratio greater than 1 in V1
- An R wave in V1 greater than 7mm in amplitude
- An R wave in V1 plus S wave in V5 or V6 greater than 10.5mm
- A qR pattern in V1
Secondary Changes
Secondary changes often include right ventricular strain pattern with T wave inversions in the right precordial leads (V1-V3) and sometimes in the inferior leads, as noted in the study 1.
Causes of RVH
Common causes of RVH include:
- Pulmonary hypertension
- Congenital heart disease
- Chronic lung disease
- Pulmonary embolism It's essential to note that ECG has limited sensitivity for detecting RVH, so echocardiography is often needed for confirmation when RVH is suspected clinically but not evident on ECG, as recommended by the American Heart Association 1.
From the Research
Criteria for Right Ventricular Hypertrophy (RVH)
The criteria for diagnosing Right Ventricular Hypertrophy (RVH) can be assessed through various methods, including echocardiography and electrocardiography (ECG).
- Echocardiographic criteria: RVH can be diagnosed using echocardiography by measuring the right ventricular wall thickness (RVWT). A study 2 found that an RVWT of greater than or equal to 5 mm is a useful criterion for diagnosing RVH, with a sensitivity of 93% and a specificity of 95% when correlated with necropsy findings.
- Electrocardiographic criteria: ECG criteria for RVH include right axis deviation, R:S ratio V1 > 1, and RV1+SV5/6 > 10.5 mm 3. Another study 4 developed a formula criterion (A + R - PL greater than or equal to 0.7 mV) and two additional criteria (R less than or equal to 0.2 mV in lead I and P less than 0.25 mV in leads II, III, aVF, V1 or V2) that yielded 94% specificity and 64% sensitivity when combined.
- Other criteria: A point scoring system was developed 5 that included criteria such as the R wave magnitude in V1, the S wave magnitude in V6, and the degree of frontal QRS axis. This system achieved 25% sensitivity and 98% specificity in patients with RVH. Vectorcardiographic criteria 6 were also developed, including the maximum QRS magnitude and the amplitude at -45 degrees (transverse plane), which achieved 60% sensitivity and 96% specificity in patients with RVH.
Comparison of Criteria
The sensitivity and specificity of different criteria for RVH vary.
- Echocardiography is more sensitive than ECG in diagnosing RVH 2.
- The amplitude of RV1+SV5/6 is a useful factor in reflecting RV remodeling, hemodynamics, and survival in patients with pre-capillary pulmonary hypertension 3.
- The proposed ECG criteria 4, 5 have higher specificity and sensitivity than existing criteria.
- Vectorcardiographic criteria 6 have higher sensitivity and specificity than ECG criteria.