Less heart is more.

The study by St John Sutton et al 1 in this issue of Circulation provides additional information on the importance of the myocardial substrate for the genesis of cardiac arrhythmias, in this instance, ventricular arrhythmias in the postinfarction remodeled human left ventricle (LV). The authors demonstrate significant relationships between ventricular arrhythmias and LV size, mass, and function at baseline, and at 1 and 2 years after infarction in a subset of 263 patients who received both echocardiographic and Holter evaluations in the Survival And Ventricular Enlargement (SAVE) trial. They found a greater preponderance of ventricular arrhythmias in those individuals with the largest LV mass, leading the authors to conclude that postinfarction remodeling is an important substrate for triggering ventricular arrhythmias.