Fetal Atrial Flutter Associated With Atrial Septal Aneurysm

Abstract Objective: To provide evidence that fetal atrial flutter (AF) caused by atrial septal aneurysm (ASA) can be completely cured by delivery. Cases: Three fetuses with ASA complicated by AF in late gestation, including hydrops fetalis in one case, were collected and completely followed up. AF in all cases completely disappeared shortly after birth. New insights gained from this study are as follows: 1) PACs or bigeminy associated with ASA can progressively change to AF. 2) AF associated with ASA can cause hydrops fetalis and intrauterine treatment is needed but delivery is definitive treatment. 3) AF associated with ASA completely resolves after birth. Conclusion: This report may have clinical impact because of providing evidence that 1) In case of AF associated with ASA, the prognosis is much better than other causes and delivery should be strongly considered. 2) Fetuses diagnosed with AF should always be looked for the presence of ASA. 3) PAC/bigeminy related to ASA, different from isolated PAC, needs close follow-up for development of SVT and AF. 4) The fetuses remote from term can benefit from intrauterine treatment to avoid hydrops fetalis, and to prolong gestation for maturity and early delivery is recommended once lung maturity is confirmed.