In this study we investigated the relationship between the size of adenoids and/or tonsils and obstructive sleep apnea syndrome (OSAS) in 19 children aged 3 to 7 years. After clinical examination by an ENT specialist, electrocardiogram (ECG), vectorcardiogram (VCG) and echocardiogram (EC) were performed while the patients were awake, and static charge sensitive bed (SCSB) method recording (noninvasive monitoring of ballistocardiogram, respiration and body movements) while asleep. After adenoidectomy and/or tonsillectomy, the volume of the tonsils and the adenoids was determined. RVH was found in 4 out of 19 children (21%). RVH findings correlated highly with the number of apneas but, surprisingly, not with measured adenotonsillar size in those children. However, at 6 months of follow-up, the VCG and EC changes had returned to normal. These results suggest that RVH is more common in children suffering from upper airway obstruction than previously believed, and that factors other than adenotonsillar size also have an influence on upper airway obstruction.