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Published on: April 21, 2014
Repolarization abnormalities and arrhythmogenesis in hypertrophic myocardium
Luigi De Ambroggi1, Pietro Francia, Guido De Ambroggi
1Department of Cardiology, IRCCS Policlinico San Donato, University of Milan, Italy. luigi.deambroggi@unimi.it
Summary
Left ventricular hypertrophy (LVH) alters heart cell electrical activity, potentially causing dangerous arrhythmias. Body surface potential mapping reveals repolarization abnormalities in LVH patients not seen on standard ECGs.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Imaging
Background:
- Left ventricular hypertrophy (LVH) causes electrophysiological changes, including prolonged action potential duration and transmural dispersion of repolarization.
- These repolarization abnormalities can lead to potentially fatal ventricular arrhythmias like ventricular tachycardia (VT).
- Standard 12-lead electrocardiogram (ECG) often fails to detect these subtle repolarization heterogeneities.
Purpose of the Study:
- To investigate repolarization abnormalities in patients with LVH using body surface potential mapping (BSPM).
- To determine if BSPM can detect heterogeneities of ventricular repolarization not apparent on standard ECG.
- To assess the utility of BSPM in identifying arrhythmogenic substrates in LVH.
Main Methods:
- Studied a group of patients with LVH due to valvular aortic stenosis.
- Utilized body surface potential mapping (BSPM) to analyze ventricular repolarization.
- Calculated similarity index and late repolarization deviation index from BSPM data.
- Compared BSPM findings in LVH patients to those in normal subjects.
Main Results:
- LVH patients exhibited a significantly lower similarity index compared to normal subjects.
- LVH patients showed a significantly higher late repolarization deviation index than normal subjects.
- These BSPM-derived indices indicated a greater degree of repolarization heterogeneity in LVH patients.
Conclusions:
- Body surface potential mapping can detect significant repolarization heterogeneities in patients with LVH.
- These abnormalities are not always evident on standard 12-lead ECG analysis.
- BSPM may offer a more sensitive method for identifying arrhythmogenic risks associated with LVH.
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