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Characterization of early repolarization during ajmaline provocation and exercise tolerance testing.
Rachel Bastiaenen1, Hariharan Raju, Sanjay Sharma
1Cardiovascular Research Centre, St George's University of London, London, UK.
Heart Rhythm
|October 24, 2012
Summary
Persistent early repolarization (ER) during exercise, especially with a horizontal/descending ST segment, may indicate higher risk for arrhythmic events in patients with unexplained syncope.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- Early repolarization (ER) in inferior leads is linked to idiopathic ventricular fibrillation but often benign.
- Currently, no risk stratifiers exist for asymptomatic ER.
Purpose of the Study:
- To assess the response to ajmaline and exercise in high-risk individuals with ER.
- To identify potential risk markers for asymptomatic ER.
Main Methods:
- Reviewed electrocardiographic data from 229 high-risk patients undergoing ajmaline and exercise testing.
- Defined ER by J-point elevation and stratified by type, territory, height, and ST morphology.
Main Results:
- Baseline ER found in 11.4% of patients; no new ER emerged during provocation.
- Persistent ER during ajmaline/exercise seen in 7 male patients with inferior/inferolateral ER and horizontal/descending ST segments.
- Persistent ER during exercise correlated with a history of unexplained syncope (P<.01); 3 patients had subtle structural abnormalities.
Conclusions:
- Persistent inferior/inferolateral ER with horizontal/descending ST segments during exercise may identify patients at higher risk for arrhythmias.
- Persistent ER during ajmaline/exercise suggests potential underlying structural abnormalities requiring further investigation.
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