简介：

简介：

简介：ObjectivesToinvestigatetheeffectofelectricalstimulationduringabsoluterefractoryperiodoncontractionandrelaxationofventricularmyocytesfromnormalguinea-pigs.MethodsTheguinea-pigventricularmyocyteswereobtainedbyenzymedigesting,andtheextentofitscontractionandrelaxationandCa^2+transientwererecordedthroughthemotionedgedetectionsystem.Results①Thecontractingextentofguinea-pigventrieularmyocytesincreased15.45±6.48%,andthepeakvelocityofshorting(contraction)andthepeakvelocityofrelengthening(relaxation)increased15.97±8.37%and21.63±8.06%respectively(n=10);②Theextentofventricularmyocytesfluorescenceratio(360/380)(F360/F380)increased22.55±9.08%,andthepeakvelocityofventricularmyocytesF360/F380increased36.75±9.77%and23.62±4.47%duringshortingandrelengtheningrespectively(n=6).ConclusionsAppropriateelectricalstimulationmaystrengthenthenormalguinea-pigcontractingandrelaxingfunctionofventricularmyocytes.

简介：AbstractAnagedmalepatientwithcoronaryheartdiseasewhichhadbeentreatedwithcoronaryarterybypassgrafts(CABG)andadministrationofmetoprolol,presentedparoxysmalvertigointhepreviousthreeweeks.The24hourssynchronic12-leaddynamicelectrocardiography(DCG)revealedmanyepisodesofsinusarrestwhichmostlywerefollowedbyA-Vjunctionalorventricularescaperhythm,thelongestsinuspauselastingmorethan14.5secondswithnosymptom.Afterwithdrawalofmetoprolol,theDCGrevealedmuchlessepisodesofsinusarrestthanon-admission,butstillsomeA-Vjunctionalandventricularescapebeats.Sicksinussyndromeswasthendiagnosed,andasynchronousdual-chamberpacemaker(DDDR)wasimplantedtwoweeksafteradmission.