Ventricular remodeling, first described in animal models of left ventricular (LV) stress and injury, occurs progressively in untreated patients after large myocardial infarction and in those with dilated forms of cardiomyopathy. The gross pathologic changes of increased LV volume and perturbation in the normal elliptical LV chamber configuration is driven, on a histologic level, by myocyte hypertrophy and apoptosis and by increased interstitial collagen. Each of the techniques used for tracking this process-echocardiography, radionuclide ventriculography, and cardiac magnetic resonance-carries advantages and disadvantages. Numerous investigations have demonstrated the value of LV volume measurement at a single time-point and over time in predicting clinical outcomes in patients with heart failure and in those after myocardial infarction. The structural pattern of LV remodeling and evidence of scarring on cardiac magnetic resonance have additional prognostic value. Beyond the impact of abnormal cardiac structure on cardiovascular events, the relationship between LV remodeling and clinical outcomes is likely linked through common local and systemic factors driving vascular as well as myocardial pathology. As demonstrated by a recent meta-analysis of heart failure trials, LV volume stands out among surrogate markers as strongly correlating with the impact of a particular drug or device therapy on patient survival. These findings substantiate the importance of ventricular remodeling as central in the pathophysiology of advancing heart failure and support the role of measures of LV remodeling in the clinical investigation of novel heart failure treatments. 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.