Phenotypes Associated with This Genotype

Genotype
MGI:4888970

• Allelic Composition: \Hcn4^tm1.1Ggc/\Hcn4^tm1.1Ggc; \A1cf^{Tg(Myh6-cre/Esr1*)1Jmk}/\A1cf⁺
• Genetic Background: involves: 129S/SvEv * C57BL/6 * FVB/N

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

cardiovascular system

decreased heart rate ( J:168248 )

• develop severe bradycardia when injected daily with tamoxifen which leads eventually to death

• heart rate reduced by 32% after 2 days of treatment and by 47% after 6 days

• isolated cells from the sino-atrial node of mice treated with tamoxifen beat spontaneously but more slowly than control cells and become progressively slower as treatment is continued to 5 days

• mice injected with isoproterenol experience heart beat acceleration similar to that occurring in control mice

abnormal impulse conducting system conduction ( J:168248 )

atrioventricular block ( J:168248 )

• when injected daily with tamoxifen, atrioventricular block becomes a 2nd degree block

• conduction ratio progresses from 2:1 to 4:1 or more

prolonged PQ interval ( J:168248 )

• when mice are injected daily with tamoxifen, a prolonged PQ interval is observed

abnormal sinoatrial node conduction ( J:168248 )

• f-channel current densities from atrioventricular cells isolated from mice after 2 and 5 days of treatment with tamoxifen are lower than for control cells

• there is a time dependent decrease in f-channel conductance

mortality/aging

premature death ( J:168248 )

• no mice survive beyond 8.5 days of treatment with tamoxifen