Detecting Changes in Arterial Blood Volume and Cardiac Efficiency

Inclusion Criteria: * Subjects or representatives must have voluntarily signed the informed consent form before any study related procedures. * Subjects can be any gender but must be between (and including) the ages of 18 and 80. * Subject ls being treated by the participating healthcare facility . ., Subject requires a trans-aortic valve replacement. * Subject is able and willing to provide informed consent and HIPM authorization. * Subject is able and willing to meet all study requirements. Exclusion Criteria: * Subject is pregnant, breast-feeding, or intends to become pregnant during the course of the study. * Subject has a personal medical history that includes: * Long O-T syndrome * Cardiac channelopathies * Seizures