Thermodilution Cardiac Output: A Concept Over 250 Years in the MakingArgueta, Erwin E, MD1; Paniagua, David, MD2Cardiology in Review: July 10, 2018 - Volume Publish Ahead of Print - Issue - p doi: 10.1097/CRD.0000000000000223 Review Article: PDF Only Abstract Author Information The need to quantify blood flow through the heart has led to the development of different techniques for its measurement. The three main approaches are the Fick method, dye dilution and thermodilution techniques. The latter two are based on the use of indicators that indirectly quantify blood flow. These have slowly been developed over centuries, from the concept of measuring blood flow, to a technique, and its clinical utility. Thermodilution is the most popular dilution method used for measuring cardiac output in the clinical setting. The information obtained during this procedure is relevant in the process of clinical decision making in patients with critical illness, valvular heart disease, and congestive heart failure. The technique increased in popularity in the early 1970’s after Swan and Ganz invented the pulmonary artery catheter which simplified thermodilution enough to utilize it as a bedside procedure. This was only possible with simple yet clever engineering methods which are not commonly known in the medical community. Despite these advancements, the concept of measuring cardiac output by dilution techniques is one where its optimal use in the clinical setting continues to be an area of investigation. The thermodilution concept and the mechanism of measuring cardiac output will be discussed in the following review. 1Department of Internal Medicine, Division of Cardiology, Texas Tech University Health Sciences Center, Lubbock, Texas 2 Division of Cardiology, Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas All authors have nothing to disclose. Correspondence Address: Erwin Eduardo Argueta MD, 3601 4th St. STOP 7520, Lubbock, Texas 79430, Email: email@example.com (new email address after 7/1/18) Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.