Malignant Hyperthermia
Malignant hyperthermia (MH) is a severe reaction to certain gases used during anesthesia and/or a muscle relaxant used to temporarily paralyze a person during surgery. Signs and symptoms of MH include marked hyperthermia, a rapid heart rate, rapid breathing, acidosis, muscle rigidity, and breakdown of muscle tissue (rhabdomyolysis). Without prompt treatment, MH can be life-threatening. People who are at increased risk for this reaction are said to have MH susceptibility. Susceptibility to MH may be caused by mutations in any of several genes and is inherited in an autosomal dominant manner. People with certain inherited muscle diseases (e.g., central core disease and multiminicore disease) also have MH susceptibility.