Atrial standstill causing congestive heart failure in a child with ostium secundum atrial septal defect.

Atrial septal defects of the ostium secundum variety are typically asymptomatic in infancy and early childhood. Congestive heart failure (CHF) may occur in the presence of significant mitral valve disease, pulmonary artery hypertension, or other diseases that lead to elevated filling pressures of the ventricles. Atrial standstill, a rare disease, was the probable cause of CHF in the 3-year-old child discussed in this report.