Mechanism of Ventricular Tachycardia Occurring in Chronic Myocardial Infarction Scar

Cardiac arrest is the leading cause of death in the more economically developed countries. Ventricular tachycardia associated with myocardial infarct is a prominent cause of cardiac arrest. Ventricular arrhythmias occur in 3 phases of infarction: during the ischemic event, during the healing phase, and after the scar matures. Mechanisms of arrhythmias in these phases are distinct. This review focuses on arrhythmia mechanisms for ventricular tachycardia in mature myocardial scar. Available data have shown that postinfarct ventricular tachycardia is a reentrant arrhythmia occurring in circuits found in the surviving myocardial strands that traverse the scar. Electrical conduction follows a zigzag course through that area. Conduction velocity is impaired by decreased gap junction density and impaired myocyte excitability. Enhanced sympathetic tone decreases action potential duration and increases sarcoplasmic reticular calcium leak and triggered activity. These elements of the ventricular tachycardia mechanism are found diffusely throughout scar. A distinct myocyte repolarization pattern is unique to the ventricular tachycardia circuit, setting up conditions for classical reentry. Our understanding of ventricular tachycardia mechanisms continues to evolve as new data become available. The ultimate use of this information would be the development of novel diagnostics and therapeutics to reliably identify at-risk patients and prevent their ventricular arrhythmias.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:134

Enthalten in:

Circulation research - 134(2024), 3 vom: 02. Feb., Seite 328-342

Sprache:

Englisch

Beteiligte Personen:

Donahue, J Kevin [VerfasserIn]
Chrispin, Jonathan [VerfasserIn]
Ajijola, Olujimi A [VerfasserIn]

Links:

Volltext

Themen:

Cause of death
Chronic total occlusion
Complications
Death
Journal Article
Mortality
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Review

Anmerkungen:

Date Completed 05.02.2024

Date Revised 14.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1161/CIRCRESAHA.123.321553

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM367903695