?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Current+concepts+on+ventricular+fibrillation%3A+A+Vicious+Circle+of+Cardiomyocyte+Calcium+Overload+in+the+Initiation%2C+Maintenance%2C+and+Termination+of+Ventricular+Fibrillation%0A&rft.creator=E.+Zaugg%2C+Christian&rft.subject=Indian+Pacing+and+Electrophysiology+Journal&rft.description=Based+on+recent+experimental+studies%2C+this+review+article+introduces+the+novel+concept+that++cardiomyocyte+Ca2%2B+and+ventricular+fibrillation+(VF)+are+mutually+related%2C+forming+a+self-maintaining++vicious+circle+in+the+initiation%2C+maintenance%2C+and+termination+of+VF.+On+the+one+hand%2C+elevated+myocyte+Ca2%2B+can+cause+delayed+afterdepolarizations%2C+triggered+activity%2C+and+consequently+life-threatening+ventricular+tachyarrhythmias+in+various+pathological+conditions+such+as+digitalis+toxicity%2C+myocardial+ischemia%2C+or+heart+failure.+On+the+other+hand%2C+VF+itself+directly+and+rapidly+causes+progressive+myocyte+Ca2%2B+overload+that+maintains+VF+and+renders+termination+of+VF+increasingly+difficult.+Accordingly%2C+energy+levels+for+successful+electrical+defibrillation+(defibrillation+thresholds)+increase+as+both+VF+and+Ca2%2B+overload+progress.+Furthermore%2C+VF-induced+myocyte+Ca2%2B+overload+can+promote+re-induction+of+VF+after+defibrillation+and%2For+postfibrillatory+myocardial+dysfunction+(postresuscitation+stunning)+due+to+reduced+myofilament+Ca2%2B+responsiveness.+The+probability+of+these+adverse+events+is+best+reduced+by+early+detection+and+rapid+termination+of+VF+to+prevent+or+limit+Ca2%2B+overload.+Early+additional+therapy+targeting+transsarcolemmal+Ca2%2B+entry%2C+particularly+during+the+first+2+min+of+VF%2C+may+partially+prevent+myocyte+Ca2%2B+overload+and+thus%2C+increase+the+likelihood+of+successful+defibrillation+as+well+as+prevent+postfibrillatory+myocardial+dysfunction.%0A&rft.publisher=Indian+Pacing+and+Electrophysiology+Group&rft.contributor=Singh%2C+Balbir&rft.contributor=Lokhandwala%2C+Yash&rft.contributor=Francis%2C+Johnson&rft.contributor=Gupta%2C+Anup&rft.date=2004-04&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=text%2Fhtml&rft.identifier=http%3A%2F%2Fcogprints.org%2F4232%2F1%2Fzaugg.htm&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F4232%2F2%2Fzaugg.pdf&rft.identifier=++E.+Zaugg%2C+Christian++(2004)+Current+concepts+on+ventricular+fibrillation%3A+A+Vicious+Circle+of+Cardiomyocyte+Calcium+Overload+in+the+Initiation%2C+Maintenance%2C+and+Termination+of+Ventricular+Fibrillation.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F4232%2F