NCJ Number
226479
Journal
Polygraph Volume: 37 Issue: 4 Dated: 2008 Pages: 256-262
Date Published
2008
Length
7 pages
Annotation
This paper proposes an explanation for what is being recorded on the cardiograph waveform during normal and deep-breathing patterns monitored during polygraph examinations.
Abstract
During polygraph examinations, the cardiovascular waveform normally maintains a relatively stable baseline. There are times, however, when the waveform undulates. This undulating pattern has been erroneously referred to as a “vagus roll.” There appears to be a difference in undulating waveforms produced when the blood-pressure cuff is in contact with the subject and when the cuff is not in contact. Respiratory influenced undulations can be caused by cuff-to-subject contact, but can also occur when there is no contact. The former resulted in a waveform in which the peak-to-peak synchrony was closely matched in time. The latter produces a waveform in which the peaks are more delayed. During breathing, vasoconstrictor neurons are activated in the inspiratory phase, leading to rhythmic vasoconstriction of blood vessels controlling blood pressure. Increased vasomotor constriction results in increased blood pressure. Increasing the depth of breathing can exacerbate this phenomenon because of increased effect on the baroreceptors. When an examinee engages in a deliberate pattern of deep and slow breathing a cyclic waveform in the cardiovascular channel can be observed. The synchronous rise and fall of the relative blood pressure is possibly a result of any combination of the physiological factors discussed in the article. Since descriptive terminology should accurately capture the essence of what is being described, this article recommends that the term “vagus roll” used to describe the undulating cardiovascular waveform be changed to the more accurate term, Respiratory Blood Pressure Fluctuation (RBPF). 4 figures and 11 references