NATURAL-HISTORY OF ASYMPTOMATIC VALVAR PULMONARY STENOSIS DIAGNOSED IN INFANCY

Background and hypothesis: Valvar pulmonary stenosis is a common conge nital heart defect. Progression of stenosis over time, even when mild initially, has been shown by serial cardiac catheterization studies in children and adults. We studied the natural history of asymptomatic v alvar pulmonary stenosis diagnosed in infancy with two-dimensional ech ocardiography and Doppler method. Methods: Between November 1986 and M arch 1993, 51 infants in the Northeast Tennessee and Southwest Virgini a region were clinically diagnosed to have isolated valvar pulmonary s tenosis. In 40 patients, the diagnosis was confirmed by two-dimensiona l echocardiogram/Doppler and color-flow mapping study at the time of p resentation, sind only their course is reported. Of 40 infants, six as ymptomatic infants (15%) showed rapid progression of pulmonary stenosi s over a relatively short period of time. Within the first 6 months of life, three of the six infants showed worsening of the stenosis needi ng intervention (one had surgical valvectomy and the others had percut aneous balloon valvuloplasty). The three other infants showed a more g radual increase of pulmonary stenosis over the first 2 years of life. Results: Pulmonary stenosis even when mild can worsen in infancy, and it is not Possible to predict which patients will follow this course. In our group of asymptomatic infants with initial mild pulmonary steno sis, 15% developed significant stenosis that needed intervention. Conc lusion: We recommend frequent follow-up of asymptomatic infants with m ild pulmonary stenosis during the first 2 years of life to detect rapi d progression that may need intervention.