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[Bifascicular block: long-term follow-up. Report of 40 cases]
Insights
Bifascicular block, a type of intraventricular conduction defect, is rare, affecting 3.3 per thousand individuals. This study found a generally good prognosis for patients with this condition, with few serious complications during follow-up.
Area of Science:
- Cardiology
- Electrophysiology
Context:
- Electrocardiogram (ECG) interpretation is crucial for diagnosing cardiac conduction abnormalities.
- Bifascicular block, specifically complete right bundle branch block with left anterior hemiblock, requires careful evaluation for prognosis.
Purpose:
- To determine the incidence of bifascicular block in a patient cohort.
- To assess the prognosis of patients diagnosed with bifascicular block through follow-up.
Summary:
- A study of 14,500 ECGs identified 40 cases of bifascicular block (complete right bundle branch block and left anterior hemiblock).
- The incidence was 0.0033 (3.3 per thousand), with a male predominance and higher frequency in older age groups.
- Associated conditions included hypertension and diabetes mellitus. During a mean follow-up of 20.2 months/patient, one patient required a pacemaker for symptomatic bradycardia; two deaths occurred, one from digitalis intoxication.
Impact:
- This study provides incidence data for bifascicular block, contributing to the understanding of intraventricular conduction defects.
- Findings suggest a generally favorable prognosis, though further research with longer follow-up and consideration of underlying cardiac conditions is warranted.
Abstract:
A total of 14,500 E.C.G. tracings were reviewed to determine the incidence of bifascicular block and those patients were followed up to assess prognosis. Forty patients with bifascicular block (complete right bundle branch block associated with left anterior hemiblock), diagnosed with standard E.C.G., according to Medrano's criteria from January 1978 to September 1980 were studied in our Service. The incidence of this intraventricular conduction defect was 0.0033 (3.3 per thousand). Males predominated over females at a rate of 2.4 to 1. This block was more frequent from the sixth to the ninth decades of life. Thirty five percent of the patients had no evidence of cardiovascular pathology; 32.5 percent had high blood pressure, 2.5 percent had coronary heart disease, 2.5 percent rheumatic heart disease, 5 percent chronic pulmonale, and 37.5 percent had diabetes mellitus as an associated finding. During the follow up which covered 20.2 months/patient, only one patient developed junctional rhythm and periods of asystolia and syncope; this case was treated with a permanent pacemaker with good results. Two patients died, one from digitalis intoxication and the other at home, the cause was not determined. It is necessary to study this conduction defect with longer follow up periods and according to the underlying heart disease, in order to assess properly the prognosis and behavior of this conduction defect.