? Heart disease is the leading cause of death in the United States. One million Americans die from heart disease or about one person every 33 seconds. Genetic alterations of mice have become a powerful tool in understanding basic signaling in cardiovascular research. The study of small rodents has increased as a result of the ease of genetic manipulation. Modification of cardiac muscle performance through gene transfer or mutation holds promise as one mechanism to prevent or correct acquired and inherited cardiac diseases. The use of rodents for pre-clinical testing of drugs requires reliable and physiological means for quantifying cardiac function in vivo. Over $69 million dollars a year are outsourced for pre-clinical testing of cardiovascular drugs. Federal regulatory guidelines require the use of one rodent species and one non-rodent species in pre-clinical toxicology studies for Investigational New Drug applications (1ND). Recently the FDA announced that all agents whether or not seeking cardiovascular indications, will be required to undergo cardiovascular screening. For these reasons, it has become very important to evaluate cardiac function and electrical recordings in small rodents. Through a partnership between a company strong in animal testing and cardiovascular phenotyping with a device development and marketing company, we will develop, test and market a novel telemetered device for measuring left ventricle pressure, left ventricle volume, and electrocardiograms simultaneously in freely moving and conscious rodents. ? ? In the proposed study we plan to demonstrate both medical and engineering feasibility of our proposed device, including the development of key device components and initial data collection. More comprehensive development and validation work will be carried out in a subsequent Phase 2 application. ? ?