Study type: Medical/biological study (experimental study)

The relationship between temperature and calcium in acute cell damage after exposure to radiofrequency or thermal energy in isolated neonatal and adult rabbit cardiac myocytes med./bio.

Published in: Pediatr Res 1998; 43 (4) Pt 1: 527-531

Aim of study (acc. to author)

To study whether differences exist between neonatal and adult myocyte responses to radiofrequency energy and if myocyte damage is a calcium-dependent process (the authors hypothesized that perfusion with a low Ca2+ concentration solution is protective for myocytes exposed to thermal energy).



Exposure Parameters
Exposure 1: 500 kHz
Exposure duration: 60 s

Exposure 1

Main characteristics
Frequency 500 kHz
Exposure duration 60 s
Exposure setup
Exposure source
Chamber Plexiglass chamber (26 mm long x 4 mm wide x 3 mm in depth) mounted on the stage of an inverted microscope.
Setup A section of fragmented coverslip with adherent isolated myocytes was placed in the plexiglass chamber. A chamber with 2 pairs of platinum electrodes (1 electrical stmulation, 1 RF energy)
Additional info Two protocols were used in this study RF energy protocol and thermal energy protocol: In RF protocol, isolated cardlic myocytes were divided into two groups. The cells in one group were not prefused during RF application where as the cells in the other group were prefused with a physiologic solution which helped in maintaining the temperature from 29 to 38°C. In thermal energy protocol, myocytes were initially prefused with physiologic Ca2+ concentration solution (1.8 mM) at physiologic temperatures from 35 to 37°C for atleast 30 s. For some cells the perfusate was changed to a low Ca2+ concentration solution (100 mM) for 60 s before the pulse of thermal perfusate.
Measurand Value Type Method Mass Remarks
power 2 W minimum - - up to 12 W
cf. remarks - - - - voltage: 10-50 V

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The major results are that 1) acute cellular injury from radiofrequency energy application is thermally mediated, 2) neonatal myocytes are more sensitive to thermal energy application than are adult cells, and 3) perfusion of myocytes with a low Ca2+ concentration solution reduced the toxic effects of thermal energy on neonatal and adult cells.

Study character:

Study funded by