<prompt> In malignant hyperthermia the increased heat production is due to :Increased muscle metabolism by excess of calcium ionsThermic effect of foodIncreased sympathetic dischargeMitochondrial thermogenesis  <response>: Ans. is a i.e. increased muscle metabolism by excess of calcium ionsRef Harrison 16the p 105 15the page 92Malignant hyperthermiais caused by inherited abnormality in sarcoplasmic reticulum of skeletal muscleDue to this there is rapid increase in intracellular calcium levels in response to certain drugs.This leads toIncreased muscle metabolismElevated temperatureRhabdomyolysisRigidityAcidosisCardiovascular instabilityIt is often fatalDrugs which cause malignant hyperthermia areHalothaneSuccinyl cholinePhenothiazines Haloperidol 