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[Indication of myocardial "memory". Gradual, persisting modulation of myocardial decrease in excitation following
1Kardiologische Abteilung der Stanford-Universität, Kalifornien.
Zeitschrift Fur Kardiologie
|December 1, 1989
Summary
Cardiac electrical repolarization, which shapes the T-wave, is influenced by excitation sequence, not just cell location. This finding reveals a new intercellular communication method in myocardial cells.
Area of Science:
- Cardiology
- Electrophysiology
- Cell Biology
Context:
- Regional differences in cardiac electrical repolarization create the electrocardiographic T-wave.
- Traditionally, these differences were attributed to intrinsic action potential duration (APD) variations in individual cardiac cells.
Purpose:
- To investigate if the sequence of cardiac electrical excitation influences ventricular repolarization.
- To determine the effect of an altered excitation sequence on action potential duration (APD) distribution.
Summary:
- Action potential duration (APD) is modulated by the ventricular excitation sequence, not solely by cell location.
- This excitation sequence-dependent modulation of APD develops and dissipates slowly, over hours.
- Findings suggest a novel form of intercellular communication enabling myocardial cells to adapt repolarization to excitation sequence changes.
Impact:
- Challenges the traditional view of APD as a fixed cellular property.
- Introduces a new mechanism of intercellular communication in the heart.
- Provides insights into the regulation of cardiac electrical activity and T-wave generation.