From the Guidelines
The EKG findings of right ventricular hypertrophy with an incomplete right bundle branch block are characterized by right axis deviation, prominent anterior forces in the right precordial leads, and a pattern similar to that of incomplete RBBB, suggesting volume overload, with ST depression and T-wave inversion in right precordial leads 1.
Key EKG Features
- Right axis deviation
- Prominent anterior forces in the right precordial leads
- Incomplete RBBB pattern
- ST depression and T-wave inversion in right precordial leads
Diagnostic Considerations
The electrocardiographic diagnosis of RVH should be made with caution, as the sensitivity of the ECG criteria is generally low, and the specificity can be high, but is dependent on the clinical context 1. The use of ancillary clinical information is crucial in the appropriate use of the ECG for the purpose of recognizing RVH.
EKG Patterns
Two patterns of RVH have been described: one similar to that of incomplete RBBB, suggesting volume overload, and a second pattern consisting of predominantly tall R waves in right precordial leads, suggesting pressure overload 1. Both patterns are associated with right axis deviation and ST-T abnormalities.
From the Research
EKG Findings of Right Ventricular Hypertrophy with Incomplete Right Bundle Branch Block
- The electrocardiogram (ECG) is a relatively insensitive tool for the detection of right ventricular hypertrophy (RVH), but some criteria have high specificity 2
- Incomplete right bundle branch block (IRBBB) can express a large palette of both benign and pathological patterns, and it is necessary to differentiate IRBBB from pathological patterns such as right ventricular enlargement 3
- IRBBB can be characterized by the RSR’ pattern and a QRS width below 100 ms, defining the crista supraventricularis (CSV) pattern, which might result from posterior apex deviation, subpulmonic area delay, or late CSV activation 3
- Special features of right bundle branch block in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia include T-wave inversions, localized right precordial QRS prolongation, and r'/s ratio < 1 4
- Abnormal signal-averaged electrocardiograms (SAECGs) can be present in patients with IRBBB, with a high incidence of false positive late potentials, which can be remedied by including the combination of QRSD and either RMS or LAS in the criteria for the presence of late potentials 5
Key EKG Parameters
- Filtered QRS duration (QRSD) < 114 ms
- Root mean square of the voltage of the last 40 ms of the QRS complex (RMS) > 20 microV
- Duration of the low amplitude signal (< 40 microV) at the terminal portion of the QRS (LAS) < 38 ms 5
- RSR’ pattern and QRS width below 100 ms defining the CSV pattern 3
- T-wave inversions, localized right precordial QRS prolongation, and r'/s ratio < 1 in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia 4