CFTR and hydrops fetalis: In contrast, in Tgαq*44 mice, basal CF velocity progressively decreased in the course of HF development, reaching a significantly lower value of basal coronary PVF in 8- and 14-month-old Tgαq*44 mice compared to age-matched FVB mice and to 4-month-old Tgαq*44 mice (Fig. 1a).