There are three ECG findings to watch for when evaluating a patient’s ECG for RVH: 

1. Absence of right ventricular conduction disturbance
2. The presence of an incomplete RBBB
3. The presence of complete RBBB

An ÅQRS_F of > +90° is often present. ST depression and T wave inversion in leads V₁ through V₂ or V₃ is present in category 1 and 2 RVH.

Right Ventricular Hypertrophy Video

Right Ventricular Hypertrophy without Right Ventricular Conduction Disturbance

Three characteristics in lead V₁ of an ECG suggestive of RVH:

• Pure R wave in a positive QRS deflection  
• 1:1 R/S ratio in lead V 
• R wave > 7 mm, S wave < 2 mm

A single positive deflection of the QRS complex in lead V₁, depicting a pure R (see Figure 1), is the distinguishing ECG finding when RVH is present. This is usually seen in patients with severe pulmonary valve stenosis and in severe RVH associated with congenital heart diseases such as Eisenmenger syndrome. In patients with mitral stenosis and severe cor pulmonale, the R is often smaller in amplitude compared to the other two disease conditions. 

These patients also present with an ÅQRS_F of > +120°.

ECG Tracing of a 22-Year-Old Man With a Large VSD

The significant R complex in V₁ is specific for RVH if there is no posterior MI and one type of preexcitation. 

The presence of a qR complex in lead V₁ is indicative of right ventricular overload. The Q wave in this instance corresponds to RVH and dilatation of the right atrium and right ventricle. This is not a significant finding of an old anteroseptal necrosis or infarct.

12-Lead ECG of a 46-Year-Old Woman With Severe Mitral Stenosis and Tricuspid Regurgitation

An R/S ratio of 1:1 or greater in lead V₁ , is indicative of RVH. An R wave of > 7 mm or an S wave of < 2 mm in V₁  are also findings in RVH.

ECG Tracing of Patient With RVH Secondary to Arrhythmogenic Right Ventricular Cardiomyopathy

Right Ventricular Hypertrophy with Incomplete RBBB and a Normal QRS Duration

The RSR Complex

• rSr’ complex in V₁, where r’< r = normal variant
• rSr’-complex, where r’> r + negative T waves in V₁ through V₃ = RVH

Healthy, young patients may have an rSr’ complex in lead V₁ as a normal variant. When the r’ wave is smaller than the initial R wave, this finding is rarely associated with RVH.

About 40% of patients with an r’ wave larger than the initial R wave do have RVH. Negative T waves in V₁ through V₃ further support a diagnosis of RVH.

The rSr’ type where the r’ > r wave is usually seen in patients with:

• Atrial septal defect who also have asymmetric negative T waves in V₁ through V₃
• Chronic pulmonary embolism
• Valvular pulmonary stenosis
• Mitral stenosis 

This pattern can also represent an intermediate state between incomplete and complete RBBB.

Note: Patients with barrel chests can also present with an rSr’ type where the r’ > r wave. This is often considered a normal variant.

12-Lead ECG of a 52-Year-Old Woman With an Atrial Septal Defect

RVH with Complete RBBB and Prolonged QRS

When differentiating RBBB from RVH, the clinician should keep in mind that there is a typical pattern of an rsR’ complex in lead V₁ that suggests the presence of RBBB with or without RVH. Additionally, sometimes only a single notched R wave is present without an S wave. Of note, the T wave is always negative in leads V₁ through V₄ with or without RVH.

Right ventricular hypertrophy appearing with RBBB can only be diagnosed if:

• The amplitude of the R’ wave > 12 mm
• The QRS duration is > 0.14 seconds due to the notching in the R wave
• The ÅQRS_F is +80° to +120°

Patients with cor pulmonale usually have a P pulmonale finding on the ECG as well, representing the cardiac effects of their chronic pulmonary hypertension.

Figure 5. 12-lead ECG of a 68-year-old man with COPD, global respiratory failure, and right ventricular failure. ÅQRSF is +110°, and an rS complex is present in all precordial leads.

Perils and Pitfalls

RBBB is found more frequently in patients without RVH. Therefore, echocardiography is recommended to confirm the presence of RVH in these cases.

Rare RVH Patterns

Some variations in ECG patterns that may indicate RVH include an S_I/S_II/S_III pattern. 

RVH can also be seen as a negative QRS complex in all precordial leads with or without incomplete RBBB and with the frontal plane QRS complex showing right axis deviation.