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The significance of pronounced left axis deviation in the presence of right bundle branch block
Insights
Patients with pronounced left axis deviation and complete right bundle branch block (rbbb) have a higher incidence of coronary artery disease. This relationship persists regardless of rbbb presence, though some patients show no clinical heart disease evidence.
Area of Science:
- Cardiology
- Electrocardiography
- Internal Medicine
Background:
- Left axis deviation and complete right bundle branch block (rbbb) are electrocardiographic findings.
- The clinical significance of these combined findings requires further investigation.
Purpose of the Study:
- To investigate the association between pronounced left axis deviation, complete rbbb, and clinical cardiac disease.
- To determine if rbbb modifies the relationship between left axis deviation and coronary artery disease.
Main Methods:
- Retrospective review of 117 patients with left axis deviation and complete rbbb.
- Comparison with 154 control patients with complete rbbb alone.
- Evaluation for clinical cardiac disease, hypertension, and emphysema.
Main Results:
- Coronary artery disease incidence was significantly higher in patients with pronounced left axis deviation.
- No significant difference in hypertension or emphysema between groups.
- Complete rbbb did not alter the association between left axis deviation and coronary artery disease.
Conclusions:
- Pronounced left axis deviation is linked to a high prevalence of clinical coronary artery disease.
- The presence of complete rbbb does not change this association.
- Some individuals with rbbb, with or without pronounced left axis deviation, may lack clinical evidence of heart disease.
Abstract:
The histories of 117 patients with left axis deviation and complete right bundle branch block (rbbb) on the electrocardiogram were reviewed for evidence of clinical cardiac disease, hypertension or emphysema. One hundred fifty-four patients with complete right bundle branch block alone served as controls. The incidence of coronary artery disease (myocardial infarction or angina) was significantly greater in the group with pronounced left axis deviation; the other factors evaluated showed no significant difference between the two groups. Pronounced left axis deviation of the mean qrs axis is associated with a high prevalence of clinical coronary artery disease. The presence of complete right bundle branch block does not alter their relationship. Some patients with complete rbbb, or with rbbb and pronounced left axis deviation, have no clinical evidence of heart disease.