NATIONAL AERONAUTICS AND SPACE ADMINISTRATION (202) 962-4155 N E A-IVS WASHINGTON, D.C. 20546 TETS: (202) 963-6925 FOR P,,ELEfSE: FRIDAY P.M. February 27, 1970 (ALSO RELEASED BY STANFORD UNIVERSITY. 2 MEDICAL CENTER, ST _A;,@FORD, CALIF.) RELEASE NO: 70-32 EXTERNAL MONITOR CHECKS,HEART FUNCTIONS Scientists from the Stanford University School of Medic-ne and the National Aeronautics and ISpace Administration's Ames Research Center successfully tested a new application of sonar (often called2 ultrasound) that can pry out secrets about the functioning of the human heart. The new use of sonar, renorted today at the meeting of the American College of Cardiology, New Orleans, can provide fundamentals of the heartbeat andblood circulation heretofore unobtainable without passing a catheter (a long thin tube) into one of the heart chambers. That procedure, known as car2diac catheterization, requires many hours and the patient is usually hospitalized. Addition al laborious procedures involve the taking of X-rays and blood samplings. -more- 2/25/70 A..pproved f or RelOa36 5 27 -2- By contrast, ultrasound studies of the heart can be done by a well-trained person in the physician's office or at the patient's bedside in a.matter of minutes. The technique can be applied as a screening procedure for patients with known or suspected heart disease. And it can be used to monitor precisely the heart's healing process in patients recovering from 2 open heart surgery or from a heart attack. -Unlike standard monitoring devices, sonar measures pre- cisely the amount of blood which is pumped out of the heart at each contraction of the heart muscle. It also measures the heart size and the backward flow of blood which indicates that the patient has a defective heart valve. The Stanford and NASA Ames (Mountain View, Calif.) researchers con2ducted sonar studies in 51 patients underooing standard catheter!-zation. Their findings, obtained by ultrasound, correlated "reasonably well" with the derrree of heart disease detected by the standard method, they reported. The work began as,a result of,interest by NASA in ultra- sonics as one of several techniques for using external instru- mentation for medical research during manned7 space flights, and coincided with interest in ultrasonics at Stanford. -more- -3- The new use of sonar was described by Dr. Richard L. Pop@), a postdoctoral fellow in cardiology at the Stanford University School of Medicine, and Dr. Donald C. Harrison, associate professor and chief of cardiology at Stanford. Working with them on the project is Dr. harq,ld Sandler, chief of the Biomedical Research Branch of the Ames2 Center. The Stanford work is supported by grants from NASA Ames, the National Institutes of Health and the American Heart Association. NASA is seeking devices to collect and record information on human heart action during space flights, according to Dr. Harrison, the principal investigator. Now that the use of sonar in heart monitoring has proved its value, work will begin to 2 build ultrasound devices small enough to be carried in orbiting space laboratories. In addition, scientists izill study the use of computers @ retrieval and instant interpretation of ultrasound for storage, recordings received on Earth. The instrumentation work will be done by researchers at NASA's Ames. Testing of the new devices in human patients 8will'be conducted by Dr. Harrison and his associates at Stanford. The sonar recordings on heart patients in the recent Stanford study were made by using a commercially available machine ,vihich emits and receives high-frequency sound waves. -more- As sonic impulses were bounced against front and rear walls of the heart, they were recorded and converted into electrical signals which were displayed on a television screen. From the patterns of ultrasonic echoes, taken when the heart is relaxed and when it contracts the researchers developed a formula enabling them to calculate precisely the volume of blood ejected by the hea2rt, and also determine the presence of abnormalities. Dr. Harrison said that from a medical standpoint the technique is promising and warrants further investigation to refine it "because it is painless, simple and safer, and less costly to the patient than present methods." Ultrasound is also being used at Stanford to detect heart changes that lead to early rejection in heart transplant 8 patients. -end-