01059nam 2200313Ka 450 991069619110332120070830103833.0(CKB)5470000002374896(OCoLC)166422218(EXLCZ)99547000000237489620070830d2007 ua 0engtxtrdacontentcrdamediacrrdacarrierHow the heart works[electronic resource] your heart's electrical system[Bethesda, Md]. :U.S. Dept. of Health and Human Services, National Institutes of Health, National Heart, Lung, and Blood Institute,[2007?]1 electronic text HTML fileTitle from title screen (viewed Aug. 30, 2007).How the heart works Heart conduction systemHeart conduction system.National Heart, Lung, and Blood Institute.GPOGPOBOOK9910696191103321How the heart works3461720UNINA