title: Possible risks of general anesthesia in patients with intraventricular conduction disturbances.
abstract: In order to assess the risk of complete AV block in patients with intraventricular conduction disturbances who undergo general anesthesia, 20 patients with various conduction defects (7 LBBB, 1 RBBB and 1st degree AV block, 1 incomplete RBBB, 9 RBBB + LAH and 2 RBBB + LPH) were studied by means of His bundle recording and corrected sinus node recovery time (CSNRT) before and after the subministration of thiopental (0.2 g I.V.), succinylcholine (1 mg/kg I.V.), Fluothane (1%) and Ethrane (1.6%). Nineteen patients displayed signs of dizziness or syncope; both the sinus rate and the CSNRT, did not undergo significant variations. A slight and not significant variation of intranodal conduction during sinus rhythm was observed after Fluothane administration (AH was prolonged by 8%). A less evident negative dromotropic action of thiopental and Ethrane was only revealed by atrial pacing. No significant variations were demonstrated in His-ventricular conduction after administration of the various drugs. The maximum average increase (1.5%) of the H-V interval was observed after administration of succinylcholine. Acute AV block distal to the His bundle appeared in three patients after succinylcholine administration.
mesh_terms: D000768:Anesthesia, General / Q000009:adverse effects*; D002037:Bundle-Branch Block; D002304:Cardiac Pacing, Artificial; D004594:Electrophysiology; D004737:Enflurane / Q000009:adverse effects; D006221:Halothane / Q000009:adverse effects; D006327:Heart Block; D006801:Humans; D012306:Risk; D013390:Succinylcholine / Q000009:adverse effects; D013874:Thiopental / Q000009:adverse effects
chemical_list: D004737:Enflurane; D013390:Succinylcholine; D013874:Thiopental; D006221:Halothane