Title :
Noninvasive stress test measurement that indicates the presence of CAD
Author :
Weaver, C.W. ; Chittenden, C.T. ; Fry, G.A. ; Brown, W.W.
Author_Institution :
SRI Int., Menlo Park, CA, USA
Abstract :
A novel technology has been developed that allows blood pressure to be more accurately measured during heavy exercise. While using computer algorithms to eliminate artifact from Korotkov sounds a systolic interval, the time from ECG (electrocardiogram) R-wave peak to the Korotkov sound onset (the RK-interval), is measured for each heart beat. When plotted against cuff pressure, the RK-interval follows a slowly varying curve. A linear regression line fitted to this curve approximates the reciprocal of the systolic slope of the pressure pulse in the brachial artery, which is correlated with dp/dt in the left ventricle. The regression line slopes were measured during treadmill stress tests at the Palo Alto Medical Clinic, and curves of slope versus heart rate were plotted for each treadmilltest. A set of shape descriptors for these curves has been developed and statistically analyzed. Patients with coronary artery disease (CAD) were discriminated from healthy patients with an accuracy rate of approximately 80%.<>
Keywords :
cardiology; haemodynamics; patient diagnosis; ECG R-wave peak; Korotkov sounds; Palo Alto Medical Clinic; brachial artery pressure pulse; computer algorithms; coronary artery disease; cuff pressure; healthy patients; heavy exercise; left ventricle; linear regression line; medical diagnostic technique; regression line slopes; systolic interval; treadmill stress tests;
Conference_Titel :
Engineering in Medicine and Biology Society, 1988. Proceedings of the Annual International Conference of the IEEE
Conference_Location :
New Orleans, LA, USA
Print_ISBN :
0-7803-0785-2
DOI :
10.1109/IEMBS.1988.94415
