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Optocardiography and Electrophysiology Studies of Ex Vivo Langendorff-perfused Hearts
Published on: November 7, 2019
Simple method of counterclockwise isthmus conduction block by comparing double potentials and flutter cycle length
Kyoung-Suk Rhee1, Keun-Sang Kwon, Sun Hwa Lee
1Division of Cardiology, Department of Internal Medicine, Research Institute of Clinical Medicine, Chonbuk National University, Jeonju, Korea.
Korean Circulation Journal
|January 6, 2010
Summary
Assessing cavotricuspid isthmus ablation for atrial flutter requires confirming conduction block. A combined electrogram interval (SD1+SD2) near the flutter cycle length accurately predicts block, ensuring effective treatment.
Area of Science:
- Electrophysiology
- Cardiac Ablation
- Atrial Flutter Management
Background:
- Cavotricuspid isthmus (CTI) ablation is key for isthmus-dependent atrial flutter.
- Distinguishing complete block from slow conduction post-ablation can be challenging.
- Flutter cycle length (FCL) reflects tricuspid annulus conduction time, useful for block confirmation.
Purpose of the Study:
- To determine the electrogram splitting degree needed to confirm complete CTI block.
- To use FCL as a reference for assessing conduction block accuracy.
Main Methods:
- Fifty patients undergoing CTI ablation were studied.
- Measured intervals: SD1 (counterclockwise conduction time) and SD2 (clockwise conduction time).
- SD1 and SD2 were recorded before and after ablation to assess block.
Main Results:
- An SD1+SD2 interval reaching 90% of the FCL accurately identified counterclockwise conduction block.
- This criterion demonstrated 94% sensitivity and 100% specificity.
Conclusions:
- A sum of SD1 and SD2 close to the FCL reliably predicts complete isthmus conduction block.
- This method offers high diagnostic accuracy and positive predictive value for counterclockwise conduction block.
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