The units of measurement of the ventricular stroke work: a review study.
BACKGROUND
The ventricular stroke work refers to the work done by the left or right ventricle to eject the volume of blood during one cardiac cycle, called stroke volume. Sarnoff and Berglund were one of the first to calculate the stroke work from the pressure volume diagram in 1954. However, they published a wrong unit of measurement for the stroke work, namely gram meter.


RESULTS
The present work reviewed 779 scientific publications between May 1954 and January 2010 which used the left or right ventricular stroke work as a variable. Interestingly, the majority (87.2%) of scientific papers since 1954 have either copied this (or a similar) wrong unit of measurement or have invented another one. Only 12.8% of the publications gave a correct unit.


CONCLUSIONS
The present search in scientific literature demonstrates that the haemodynamic variable ventricular stroke work, which is used daily by thousands of medical doctors and scientists, was specified in an incorrect manner for 56 years in the majority of scientific papers. A correct unit of measurement, of course, is an imperative condition when comparing scientific papers. The aim of this publication is the elimination of incorrect units of measurement of the ventricular stroke work variable in all future scientific papers. Moreover, the present work facilitates the interpretation of at least some of the studies containing the ventricular stroke work variable published up to now.
Schramm
Wolfgang
W
Department of Anaesthesia, Medical University of Vienna, Austria. Wolfgang.schramm@meduniwien.ac.at
D056808:Biostatistics; D006801:Humans; D008991:Monitoring, Physiologic / Q000706:statistics & numerical data; D013318:Stroke Volume / Q000502:physiology; D016276:Ventricular Function / Q000502:physiology*; D014894:Weights and Measures
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