Novel ECG criteria for right ventricular systolic dysfunction in patients with right bundle branch block.

BACKGROUND

Altered hemodynamics of a failing right ventricle (RV) may place stress on the right bundle branch and Purkinje network, which may be evident as conduction delay on surface electrocardiogram (ECG). We hypothesized that prolonged R' duration in lead V1 would be an indicator of RV dysfunction in patients with RBBB.

METHODS

The Mayo Clinic Arizona echocardiography database was reviewed from 2007 to 2009 to identify patients with RV dysfunction and coexistent right bundle branch block (RBBB). Specific ECG features of RBBB were compared between the RV dysfunction cohort and a randomly selected control population. Features found to be predictive of RV dysfunction were then tested on 100 consecutive patients with RBBB on ECG between January and June 2010.

RESULTS

In lead V1, the QRS duration was longer in the RV dysfunction cohort (164 ± 22 ms) compared to controls (148 ± 12 ms), predominantly due to R' prolongation (117 ± 27 ms vs. 87 ± 13 ms, p<.001). Retrospective analysis suggested that V1 R' duration ≥ 100 ms may be 82.3% specific for the presence of RV systolic dysfunction. When applied prospectively, V1 R' duration ≥ 100 ms yielded sensitivity and specificity of 39.0% and 82.9% respectively for detection of abnormal RV systolic function with a positive predictive value of 76.7%.

CONCLUSION

Lead V1 R' duration ≥ 100 ms is predictive of RV systolic dysfunction in patients with RBBB.