In malignant hypehermia, excess heat production is due to:: (A) Increased muscle metabolism by excess of calcium ions, (B) Thermic effect of food, (C) Increased sympathetic discharge, (D) Mitochondrial thermogenesis
Answer is A. Malignant hypehermia is an autosomal-dominant disease in which the defect is in RyR1 gene. When such individuals are administered inhalation anaesthetics (halothane or ether) or muscle relaxant succinylcholine , there is excess release of Ca++ in the sarcoplasm. This increases muscle metabolism.