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Ultrasonic attenuation of myocardial tissue: Dependence on time after excision and on temperature

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M. O'Donnell, J. W. Mimbs, B. E. Sobel, J. G. Miller · 1977

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Ultrasonic attenuation in dog heart muscle fell about 20% as temperature rose from 20.5°C to 37°C.

Plain English Summary

Summary written for general audiences

Researchers measured how ultrasound waves pass through heart muscle tissue at different temperatures and time periods after removal from animals. They found that ultrasound absorption in heart tissue decreases by about 20% as temperature increases from room temperature to body temperature. The tissue remained stable for 4 hours at cool temperatures but showed changes at warmer temperatures.

Why This Matters

This 1977 study concerns ultrasound rather than the radiofrequency fields from wireless devices. The ultrasonic attenuation coefficient of myocardium decreased approximately linearly with increasing temperature over 20.5°C to 37°C, with the value at 37°C about 20% lower than at 20.5°C. Excised tissue kept at 35°C changed by about 20% over four hours, while tissue kept near 20°C showed no statistically significant change for several hours, which matters for in vitro measurements. The authors found the temperature dependence parallel to that of the square root of the viscosity, so a model based on viscous relative motion losses is not inconsistent with the measurements.

Figures from the Original Paper

Diagram extracted from the original research document.

graphPage 2 - Figure 1 illustrates the slope of the attenuation (2–10 MHz) of normal myocardium as a function of time after excision for two temperatures.
p. 2 of the original PDF
Cite This Study
M. O'Donnell, J. W. Mimbs, B. E. Sobel, J. G. Miller (1977). Ultrasonic attenuation of myocardial tissue: Dependence on time after excision and on temperature.
Show BibTeX
@article{ultrasonic_attenuation_of_myocardial_tissue_dependence_on_time_after_excision_an_g5013,
  author = {M. O'Donnell and J. W. Mimbs and B. E. Sobel and J. G. Miller},
  title = {Ultrasonic attenuation of myocardial tissue: Dependence on time after excision and on temperature},
  year = {1977},
  
  
}
No DOI on file for this study.

Quick Questions About This Study

The ultrasonic attenuation coefficient of heart muscle decreased approximately linearly with increasing temperature from 20.5°C to 37°C (body temperature), with the value at 37°C about 20% lower than at 20.5°C.
Researchers tested ultrasonic frequencies from 2-10 MHz on myocardial (heart muscle) tissue, measuring how well the tissue absorbed these ultrasonic waves under different temperature and time conditions.
Heart tissue showed stable ultrasound absorption properties for 4 hours when kept at 19.5°C, but demonstrated a 20% increase in absorption over 4 hours at the warmer 35°C temperature.
Yes, the ultrasonic attenuation of heart tissue decreased approximately linearly with increasing temperature, so tissue at 37°C attenuated about 20% less ultrasound than tissue at 20.5°C.
Measurements made in vitro at about 20°C differ from those at 37°C by about 20%, so results obtained at different temperatures must be compared with that difference in mind. Tissue held at 35°C also changed by about 20% over four hours after excision.