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Supernormal conduction in a case of Mobitz type II atrioventricular block
M Ayusawa1, H Sakurada, Y Hiyoshi
1Department of Cardiology, Tokyo Hiroo Metropolitan Hospital, Japan.
Journal of Electrocardiology
|April 9, 1998
Summary
This study details a rare case of supernormal conduction in a patient with Mobitz type II atrioventricular block. The findings suggest a novel mechanism involving retrograde concealment in the His bundle region.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Electrophysiology
Background:
- Mobitz type II atrioventricular (AV) block is a serious conduction abnormality.
- Understanding the mechanisms of AV conduction is crucial for patient management.
Observation:
- A 52-year-old woman presented with Mobitz type II AV block and right bundle branch block.
- Electrophysiologic study demonstrated transient HV interval block with recovery at shorter coupling intervals, indicative of supernormal conduction.
Findings:
- True supernormal conduction was observed, characterized by recovery without significant interval prolongation.
- Isoproterenol enhanced supernormal conduction, while atropine had a less pronounced effect.
- Retrograde concealment in the His bundle region via the blocked right bundle branch was proposed as a mechanism.
Implications:
- This case expands the understanding of complex AV conduction abnormalities.
- The findings may inform diagnostic and therapeutic strategies for patients with AV block.
- Further research into supernormal conduction mechanisms is warranted.