@article{123ed17295724b4387a23b66fd653ecb,
title = "Influence of respiration on recording cardiac potentials. Isopotential surface-mapping and vectorcardiographic studies*",
abstract = "Isopotential surface-mapping studies in normal children indicated that inspiration produces an inferior shift of potential maxima and minima on the body surface with a concomitant decrease in their absolute potential values. There was a terminal maximum under the right clavicle with inspiration which was absent during expiration. Review of the body surface potential distribution provided a clearer picture of changing events of respiration than could be acquired from analysis of data acquired from a few selected points, as is done in vector-cardiography. Respiratory changes were more prominent in abnormal than in normal vector-cardiograms. It is suggested that when quantitative vectorcardiographic analysis is used for comparison of patient groups, it would be optimal to compare beats recorded during resting expiration.",
author = "Flaherty, {John T.} and Blumenschein, {Sarah D.} and Alexander, {Ann W.} and Gentzler, {Richard D.} and Gallie, {Thomas M.} and Boineau, {John P.} and Spach, {Madison S.}",
note = "Funding Information: All data were recorded on magnetic tape and transcribed by an analog-to-digital converter at a rate of 926 samples/set. {\textquoteleft}I{\textquoteleft}he digital tapes then were analyzed by an IBM 7072 computer. l{\textquoteleft}he time of the baseline crossing of the intrinsicoid deflection of QRS in the time-reference lead was used for time alignment of the 30 separately recorded blocks of data. Voltages in all tracings were determined at approximately 1 msec. intervals throughout the QRS. The output was presented for each millisecond in a format which * From the Departments of Pediatrics, Medicine and Biomathematics, Duke University School of Medicine, and the Department of Mathematics, Duke University, Durham, N. C. This study was supported in part by U. S. Public Health Service Grants HE 8667, 5372 and 5716. t Student Research Fellowship, Duke University School of Medicine. $ For reprints, please address Madison S. Spach, M.D., Department of Pediatrics, Duke University Medical Center, Durham, N. C. 27706.",
year = "1967",
month = jul,
doi = "10.1016/0002-9149(67)90106-3",
language = "English (US)",
volume = "20",
pages = "21--28",
journal = "American Journal of Cardiology",
issn = "0002-9149",
publisher = "Elsevier Inc.",
number = "1",
}