Baseline ECG and VT ablation: Is there more to it than just skimming the surface?

Abstract

A growing body of literature supports left ventricular scar as an outcome predictor in patients with ischemic cardiomyopathy. While ejection fraction has been traditionally recognized as a “risk stratifier” in patients with coronary artery disease, limitations clearly exist as evidenced by relatively low rates of appropriate implantable cardioverterdefibrillator (ICD) discharges in devices placed for primary prophylaxis. Scar burden is emerging as a new marker to predict outcomes. Cardiac magnetic resonance imaging (MRI) is the gold standard for determining location and burden of myocardial scar in patients with ischemic cardiomyopathy, and emerging data from several studies have shown a relation not only to mortality 1,2 but also to arrhythmia burden. 3,4 Late gadolinium enhancement is used to delineate scar, but several factors can affect this determination, including methods to quantify scar (which in some cases may be semiautomated) and impact of the infarct border zone is still unclear. Cardiac MRI is not readily available at all centers and not readily feasible in patients with ICDs at least in their current iteration. Therefore, electrocardiogram (ECG) quantification of scar is a useful proposition as a simple, noninvasive analysis and the Selvester score has been used as a surrogate. This score has been shown to correlate with MRI scar and to predict inducible monomorphic ventricular tachycardia (VT)