Which sensitizes the myocardium to catecholamines

Halothane-catecholamine sensitization also promotes abnormal automaticity of dominant and latent atrial pacemakers. These effects may produce premature ventricular contractions and arrhythmias originating from the His bundle. Intact sinoatrial node function reduces the incidence of epinephrine induced ventricular escape during halothane anesthesia and is protective against His bundle arrhythmias. Halothane and, to a lesser extent, other volatile anesthetics sensitize the myocardium to the arrhythmogenic effects of epinephrine. Sensitization is the interaction between volatile anesthetics and catecholamines that leads to reductions in the threshold for both atrial and ventricular arrhythmias. Halothane and, to a lesser extent, isoflurane may be arrhythmogenic in Purkinje fibers in experimental myocardial infarction by facilitating reentrant activity or increasing temporal dispersion of the refractory period recovery. Ref: Miller's anesthesia 8th edition Ref: Morgan & Mikhail's clinical anesthesiology 6e