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Serial electrophysiologic studies in patients with chronic bundle branch block
Circulation
|June 1, 1982
Summary
Approximately 33% of patients with chronic bundle branch block experience progressive atrioventricular (AV) conduction disease. This progression, affecting both AV nodal and infranodal pathways, occurs independently and is more common in women, impacting AV block development.
Area of Science:
- Cardiology
- Electrophysiology
- Internal Medicine
Background:
- Chronic bundle branch block (BBB) can predispose individuals to atrioventricular (AV) conduction abnormalities.
- Understanding the progression of AV conduction disease in BBB is crucial for predicting heart block development.
Purpose of the Study:
- To investigate the progression of atrioventricular (AV) conduction system disease in patients with chronic bundle branch block (BBB).
- To determine the incidence and characteristics of progressive AV block in this patient population.
Main Methods:
- Serial His bundle recordings were performed in 90 patients with chronic BBB over a mean of 30 months.
- Atrioventricular (AV) conduction times, including AH (AV nodal) and HV (infranodal) intervals, were measured and compared between studies.
Main Results:
- 28% of patients showed increased AH intervals and 32% showed increased HV intervals; only 10% had parallel increases.
- Progression of infranodal conduction disease was more frequent in women.
- AV nodal block occurred in 7 patients, while 12 progressed to infranodal block, with distinct patterns of interval changes.
Conclusions:
- About 33% of patients with chronic BBB develop progressive AV conduction disease, with independent progression of AV nodal and infranodal disease.
- Infranodal disease progression is more common in women.
- AV nodal disease can cause AV block without significant AH interval changes, while infranodal block typically involves HV interval lengthening; progression is hard to predict.