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Left ventricular repolarization heterogeneity as an arrhythmic substrate in heart failure
1Cardiovascular Institute, Mount Sinai School of Medicine, New York, NY, USA. fadi.akar@mssm.edu
Minerva Cardioangiologica
|May 5, 2010
Summary
Heterogeneous remodeling of ion channels and proteins in heart failure creates electrical gradients. These gradients in the left ventricle increase the risk of arrhythmias and sudden cardiac death.
Area of Science:
- Cardiovascular Physiology
- Cardiac Electrophysiology
Background:
- Pathophysiological remodeling affects cardiac function from molecular to organ levels.
- Changes in the electrophysiological substrate at the tissue level are crucial for arrhythmias.
Purpose of the Study:
- To provide an overview of mechanisms causing heterogeneous remodeling in the left ventricle.
- To explain how this remodeling creates repolarization gradients and predisposes to arrhythmias.
Main Methods:
- Review of mechanisms involving ion channels, calcium handling proteins, gap junctions, and stretch-activated pathways.
- Analysis of regional and transmural differences in myocardial electrical properties.
Main Results:
- Heterogeneous remodeling of key proteins leads to significant repolarization gradients.
- These gradients exist across different regions and layers of the left ventricle.
Conclusions:
- Repolarization gradients resulting from heterogeneous remodeling form an electrophysiological substrate for arrhythmias.
- This substrate contributes to sudden cardiac death in patients with heart failure.
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