Usage Information
Citation Information: J Clin Invest. 1970;49(6):1166-1177. https://doi.org/10.1172/JCI106331.
Abstract
Pulsus alternans was induced in 11 anesthetized, open-chest dogs by rapid atrial pacing, and the left ventricular filling characteristics and length-tension-velocity relationship of alternating beats were compared. The end-diastolic circumferences (cire) of the strong beats were slightly, but significantly, increased over the weak beats (7.3 > 6.9 cm, P < 0.01), confirming that diastolic filling does alternate in pulsus alternans. This alternation in initial fiber length seemed to result from an alternation in the prior end-systolic length, rather than from an alternation in diastolic filling time or compliance. There was also no difference in end-diastolic tension as measured by an isometric strain gauge suggesting no difference in contractile element relaxation before weak and strong beats.
Authors
R. Joe Noble, Donald O. Nutter
Usage data is cumulative from February 2024 through February 2025.
| Usage | JCI | PMC |
|---|---|---|
| Text version | 88 | 2 |
| 52 | 16 | |
| Scanned page | 452 | 1 |
| Citation downloads | 43 | 0 |
| Totals | 635 | 19 |
| Total Views | 654 | |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)