日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

Congenital central hypoventilation syndrome (CCHS), caused by pathogenic paired-like homeobox 2B (PHOX2B) variants, leads to hypoventilation due to respiratory center dysfunction. Bradyarrhythmia can also complicate CCHS due to autonomic dysfunction, potentially leading to sudden death, and the efficacy of pacemaker implantation (PMI) in preventing these events was previously reported. However, PMI in patients with CCHS has been rarely reported in Japan and the indications for PMI have not been established. Here, we present the case of a 5-year-old girl diagnosed with CCHS based on the identification of a 20/27 polyalanine repeat expansion mutation in PHOX2B. She was initiated on home mechanical ventilation. At 2 years of age, she temporarily lost consciousness associated with consecutive sinus pauses of 3.6 and 4.2 seconds while eating during hospitalization for a respiratory infection; the event was later defined as deglutition syncope. At 4 years of age, she experienced another episode of transient loss of consciousness at home. The recurrent syncope was presumed to be due to CCHS-related autonomic dysfunction, and PMI in VVI mode was performed at 5 years of age. After PMI, she did not experience syncopal episodes. In patients with CCHS, bradyarrhythmia due to autonomic dysfunction can be progressive and PMI should be considered in cases with a clear correlation between bradyarrhythmia and symptoms. However, the PMI indication remains debatable in asymptomatic patients and in those without unclear bradyarrhythmia–symptom correlation. Surveying bradyarrhythmia in Japanese patients with CCHS is crucial for establishing more appropriate PMI criteria.