GSK3B and hydrops fetalis: Here we demonstrate that cardiac specific partial conditional KO of GSK3β in the atrium of Akita mice results in a marked reversal of the parasympathetic dysfunction observed in the Akita mouse as measured by an increase in the HF fraction of HRV and of the magnitude of the increase in heart rate in response to parasympathetic blockade by atropine and the decrease in heart rate in response to carbamylcholine treatment.