24-hour BP in children with congenital central hypoventilation syndrome.

Objective: To study circadian BP patterns in patients with congenital central hypoventilation syndrome (CCHS).

Design: Case-control study.

Setting: Teaching hospital in Paris, France.

Patients: Eleven patients with CCHS (median age, 13 years; range, 6 to 18 years) and 11 sex- and height-matched control subjects.

Intervention: None.

Methods: Each subject underwent 24-h ambulatory BP monitoring. Oxygen saturation and end-tidal PCO(2) were monitored noninvasively. Polysomnography was performed to determine sleep times. All patients with CCHS received mechanical ventilation during sleep. Mean values for systolic BP (SBP) and diastolic BP (DBP) during wakefulness and sleep were analyzed. Nocturnal BP "dipping" was defined as the difference in mean SBP (and/or DBP) between wakefulness and sleep, divided by individual waking mean values. BP "dippers" were defined as subjects showing at least 10% nocturnal dipping.

Results: Patients with CCHS had BPs in the low normal range of normative data. As compared to control subjects, patients with CCHS had lower BP during wakefulness (p = 0.003 and p = 0.016 for SBP and DBP, respectively), and higher BP during sleep (p = 0.016 and p = 0.002). Nocturnal BP dipping was abnormally reduced in patients with CCHS (p = 0.000). Ten of the 11 patients with CCHS were BP nondippers, compared to none of the control subjects.

Conclusion: The abnormal circadian BP pattern observed in children and adolescents with CCHS may be related to autonomic nervous dysfunction. Lifelong cardiovascular follow-up is recommended for patients with CCHS.