Record Display for the EPA National Library Catalog


Main Title Continuous Noninvasive Monitoring of Left Ventricular Function during Exercise by Thoracic Impedance Cardiography Automated Derivation of Systolic Time Intervals.
Author Sheps, D. S. ; Petrovick, M. L. ; Kizakevich, P. N. ; Wolfe, C. ; Craige, E. ;
CORP Author Health Effects Research Lab., Research Triangle Park, NC.
Year Published 1982
Report Number EPA-600/J-82-288;
Stock Number PB83-189647
Additional Subjects Exercise(Physiology) ; Electrocardiography ; Stress(Physiology) ; Heart ; Humans ; Reprints ; Noninvasive tests
Library Call Number Additional Info Location Last
NTIS  PB83-189647 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 9p
Systolic time intervals (ST) obtained during exercise are useful as a method of estimating global left ventricular function. The conventional method, however, which requires a carotid pulse tracing as well as a phonocardiogram of high quality, is technically difficult under conditions of exercise. The authors have validated a new method of obtaining STI which employs the first derivative of thoracic electrical impedance (DZ/DT). The DZ/DT was recorded using surface electrodes and a microcomputer for automated signal processing. The new method was studied in 20 male normal subjects (aged 18 to 53 years) at rest and during increasing levels of upright exercise. Heart rate ranged from 61 to 173 beats/min. Results obtained simultaneously by both techniques showed no significant difference. Thus impedance cardiography allows continuous monitoring of STI during exercise and may prove to be a valuable addition to multistage stress testing.