DigoxinMortalityHospital MortalityInfant MortalityDigitoxinCardenolidesCardiotonic AgentsCause of DeathCardiac GlycosidesChild MortalityMedigoxinMaternal MortalityTime FactorsEleutherococcusRetrospective StudiesCohort StudiesFollow-Up StudiesTreatment OutcomeProportional Hazards ModelsProspective StudiesHeart FailureAnti-Arrhythmia AgentsSurvival AnalysisDigitalis GlycosidesSurvival RateInfant, NewbornDrug InteractionsNeriumUnited StatesAge FactorsCardiovascular DiseasesRisk AssessmentMortality, PrematureOuabainRadioimmunoassayPrognosisPerinatal MortalityP-GlycoproteinIncidence