<qa>  What is the confidence level of the patients in Group 1?The proposed study will be a single center, prospective, pilot evaluation of the ventricular effects of DCM and the effect of Biventricular pacing for the treatment of DCM in pediatric patients. All patients will be enrolled following referral 1 for implantation of a biventricular pacemaker for the treatment of cardiomyopathy or 2 for a research echocardiogram due to the diagnosis of dilated cardiomyopathy without pacemaker therapy. Inclusion criteria will be those children with dilated cardiomyopathy or children referred for biventricular pacemaker implantation or upgrade with the diagnosis of dilated cardiomyopathy. All participants will be required to sign an informed consent prior to any procedures. We anticipate enrolling 50 patients between March 1, 2005 and February 28, 2006 for this study: 25 patients in Group 1 and 25 patients in Group 2. This will give us a confidence level of 95 with a confidence interval of 4-6. 