Do endothelin receptor antagonists have an antiarrhythmic potential during acute myocardial infarction? Evidence from
Dimitrios L Oikonomidis1, Giannis G Baltogiannis, Theofilos M Kolettis
1Department of Cardiology, University of Ioannina, 1 Stavrou Niarxou Avenue, 45110 Ioannina, Greece.
Insights
Sudden cardiac death is often caused by ventricular tachyarrhythmias after myocardial infarction. Endothelin-1 plays a key role in these arrhythmias, suggesting potential therapeutic targets.
Area of Science:
- Cardiovascular Pathophysiology
- Molecular Cardiology
- Pharmacology
Background:
- Sudden cardiac death (SCD) is a significant health issue, frequently resulting from ventricular tachyarrhythmias post-acute myocardial infarction (MI).
- The intricate mechanisms linking acute coronary occlusion to ventricular arrhythmias are not fully elucidated.
- Endothelin-1 (ET-1) levels increase early in acute MI and contribute to arrhythmogenesis.
Purpose of the Study:
- To review the role of endothelin-1 in the development of ventricular arrhythmias during acute myocardial infarction.
- To explore the potential of endothelin receptor antagonists as antiarrhythmic agents in ischemic conditions.
- To summarize current knowledge and propose future research directions regarding ET-1's pro-arrhythmic effects.
Main Methods:
- Review of experimental and clinical studies on endothelin-1's role in myocardial infarction and arrhythmias.
- Analysis of the electrophysiologic actions of endothelin-1 on cardiomyocytes.
- Examination of the effects of endothelin receptor antagonists (ETA and ETB) on ischemia-induced arrhythmias.
Main Results:
- Endothelin-1 prolongs cardiomyocyte action potential duration and increases spontaneous calcium transients, leading to early afterdepolarizations and triggered ventricular arrhythmias.
- Endothelin-1 amplifies sympathetic stimulation, exacerbating ventricular arrhythmogenesis during acute MI.
- Arrhythmogenic effects are primarily mediated via ETA receptor stimulation, though ETB receptor involvement remains debated.
Conclusions:
- Endothelin-1 is a significant mediator of ventricular arrhythmias in acute myocardial infarction.
- Endothelin receptor antagonists represent a potential therapeutic strategy for managing these arrhythmias.
- Further investigation is needed to clarify the precise roles of ETA and ETB receptors and to optimize therapeutic interventions.
Abstract:
Sudden cardiac death constitutes a major health-related problem. In the majority of cases, sudden cardiac death is due to ventricular tachyarrhythmias secondary to acute myocardial infarction. The pathophysiologic chain of events leading to ventricular tachyarrhythmias after acute coronary occlusion is complex and incompletely understood. Experimental and clinical studies have indicated that endothelin-1 production rises markedly very early in the course of myocardial infarction. Endothelin-1 exerts significant electrophysiologic actions on ventricular cardiomyocytes and participates in the genesis of ischemic ventricular tachyarrhythmias. Endothelin-1, acting via two G-protein-coupled receptors (ETA and ETB), prolongs the action potential duration and increases the occurrence of spontaneous calcium transients, resulting in early afterdepolarizations and ventricular tachyarrhythmias via triggered activity. Moreover, endothelin-1 enhances sympathetic stimulation, a well established contributor to ventricular arrhythmogenesis during acute myocardial infarction. Despite these considerations, the therapeutic potential of endothelin receptor antagonists as antiarrhythmic drugs during myocardial ischemia/infarction is still under investigation. To date, a number of endothelin-1 receptor antagonists are available, presenting different degrees of selectivity for ETA and ETB receptors. The arrhythmogenic effects of endothelin-1 are exerted mainly via stimulation of the ETA receptors, but the role of ETB receptors remains controversial, as previous studies have produced conflicting results. This review summarizes the current state-of-the-art on the role of endothelin-1 in the genesis of ventricular arrhythmias during acute myocardial infarction and raises some hypotheses that could be explored in future studies.
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