Hello everyone, I am currently being evaluated by a cardiologist who has had no idea what is causing my cardiac symptoms. I found this article: http://www.dfwcfids.org/medical/cheney/hrt04lng.htm and strongly believe this is my situation. That is, that my cardiac output is severely limited upon standing/exertion. My question is: What test should I ask my cardiologist for, and how specifically should it be done? The article linked above states that an Impedence Cardiograph test should be done, and it should be done both lying down and upright (and if permitted, on a tilt-table at angles in-between horizontal and vertical) It also states they used a specific formula (thoracic algorithm) to calculate, one that was developed by the university of Minnesota. To quote directly from the above link: "The University of Minnesota algorithm has been approved by the FDA as a valid measurement of Q. The point is that Medicare pays for this. It's been clinically validated by a government agency and is not considered experimental or researchas long as you use this algorithm. That's important, because whenever this test result filters back to a cardiologist, the first thing many say is, well, but, you know, that's not accurate. And indeed, it may not be accurate, depending on the machine and the algorithm it uses." So can anyone please weigh in on this? I feel that this can truly be a huge step forward for me if it is done properly. I've searched this forum and have found that other names / terms being used for this test can be: - Idiopathic Cardiomyopathy test - Impedance plethysmography - "BioZ," for biologic impedance as per this thread: http://forums.phoenixrising.me/showthread.php?340-cheney-heart-test-name-! So how do I ask my cardiologist for it, and how do I specify the proper algorithm / patient positioning, etc. ? Any and all help is very appreciated. I would consider it a huge bonus if anyone has had this test done and can share their expertise with me, but I'll take any reply I can get. Thank you in advance.