The in vitro determination of susceptibility to malignant hyperthermia

Paul A. Iaizzo, Frank Lehmann‐Horn

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


To evaluate the reliability of the in vitro contracture test for susceptibility to malignant hyperthermia, we studied muscles from normal pigs and those susceptible to malignant hyperthermia. We performed the contracture test with various muscles from the same animal. Trapezius and intercostal muscles gave similar results, whereas the extensor digiti II muscle had lower sensitivities to both caffeine and halothane. Thus, the muscle chosen to determine susceptibility to malignant hyperthermia is important. In several animals, a false negative diagnosis would have resulted if only the distal muscle had been studied, and this was true even if weak contractures (<200 mg) were considered significant. In addition, we compared the response to caffeine or halothane of cut and intact muscle fibers. Although the cut fibers were depolarized, the sensitivity to these drugs was unchanged. Hence, results of the in vitro contracture test are independent of the resting membrane potential.

Original languageEnglish (US)
Pages (from-to)184-190
Number of pages7
JournalMuscle & Nerve
Issue number3
StatePublished - Mar 1989


  • caffeine
  • contracture
  • halothane
  • malignant hyperthermia


Dive into the research topics of 'The in vitro determination of susceptibility to malignant hyperthermia'. Together they form a unique fingerprint.

Cite this