Vulnerability for ventricular arrhythmias in patients with chronic coronary total occlusion

ABSTRACT

Introduction

The presence of a chronic total occlusion (CTO) is associated with an increased risk of ventricular arrhythmias.

Areas covered

This review provides an overview of the relationship between CTO and ventricular arrhythmias, arrhythmogenic mechanisms, and the effect of revascularization.

Expert opinion

Studies in recipients of an implantable cardioverter-defibrillator (ICD) have shown that a CTO is an independent predictor of appropriate ICD therapy. The myocardial territory supplied by a CTO is a pro-arrhythmogenic milieu characterized by scar tissue, large scar border zone, hibernating myocardium, residual ischemia despite collaterals, areas of slow conduction, and heterogeneity in repolarization. Restoring coronary flow by revascularization might be associated with electrical homogenization as reflected by a decrease in QT(c) dispersion, decrease in T wave peak-to-end interval, reduction of late potentials, and decrease in scar border zone area. Future research should explore whether CTO revascularization results in a lower burden of ventricular arrhythmias. Furthermore, risk stratification of CTO patients without severe LV dysfunction is interesting to identify potential ICD candidates. Potential tools for risk stratification are the use of electrocardiographic parameters, body surface mapping, electrophysiological study, and close rhythm monitoring using an insertable cardiac monitor.

KEYWORDS:

• Chronic total occlusion
• coronary artery disease
• implantable cardioverter-defibrillator
• percutaneous coronary intervention
• sudden cardiac death
• ventricular arrhythmias

Article highlights

• A CTO is associated with an increased risk of ventricular arrhythmias.

• The territory supplied by a CTO is a proarrhythmogenic milieu characterized by scar tissue, large scar border zone, hibernating myocardium, residual ischemia despite collaterals, areas of slow conduction, and heterogeneity in repolarization.

• Restoring coronary flow by CTO PCI is associated with electrical homogenization as reflected by a decrease in QT(c) dispersion, decrease in T wave peak-to-end interval, reduction of late potentials, and decrease in scar border zone area.

• Future studies should focus on the effect of CTO PCI and better risk stratification of patients with a CTO for a prophylactic ICD.

Declaration of interest

SC Yap has received a research grant from Medtronic for the VACTOR study. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.