Leukemia Receiving Chemotherapy
To the Editor: Functional closure of the ductus arteriosus generally occurs within hours of birth, but it takes up to 6 weeks for anatomic closure to be complete. Spontaneous closure of the patent ductus arteriosus (PDA) after the first year of life is rare.
We describe a 3-year-old child who was referred to our hospital at the age of 2 years with the diagnosis of acute lymphoblastic leukemia (ALL). He was noted, incidentally, to have a continuous murmur at the left upper sternal border in both the recumbent and upright positions. Color and Doppler echocardiography revealed a small PDA with a left to right shunt, and a normal estimated pulmonary arterial systolic pressure. The patient received chemotherapy for the treatment of his leukemia consisting of vincristine, asparaginase, prednisone, and daunorubicin. A follow-up cardiac evaluation 1 year later revealed disappearance of the continuous murmur initially heard. Repeat color and Doppler echocardiography revealed normal cardiac anatomy with disappearance of the PDA initially noted.
Spontaneous closure of PDA after the age of 1 year, although rare, has been described in specific conditions and at different ages . Closure of a PDA may follow healing of an infective endocarditis or from occlusion by a bland thrombus . Exceptional examples of complete late spontaneous closure of PDA between 7 and 14 years and at age 19 years have also been reported .
We speculate that PDA closure in our 3-year-old patient may have been related to one of the chemotherapy agents used since spontaneous closure of the ductus is so uncommon beyond 1 year of age. We suggest that in a patient with ALL and a small PDA who is scheduled to have elective closure of the ductus, completion of the chemotherapy course could be awaited to see whether our experience can be duplicated.