Life-threatening cardiac arrhythmias in congenital central hypoventilation syndrome

Congenital central hypoventilation syndrome (CCHS) patients are at risk for life-threatening cardiac arrhythmias, and presentation is dependent on their PHOX2B gene mutation. We describe the presentation of life-threatening arrhythmias in our cohort of CCHS patients. We reviewed the records of 72 CCHS patients seen at CHLA from 2004 to 2018. Data collected included demographics, PHOX2B genotype, ventilatory support, clinical symptoms, ambulatory cardiac monitoring results, and presence of cardiac pacemaker. Sixteen of 72 patients had evidence of potential life-threatening cardiac arrhythmias. PHOX2B genotypes were 20/25 polyalanine repeat expansion mutation (PARM), 20/26 PARM, 20/27 PARM, 20/32 PARM, and c.245C > T non-polyalanine repeat mutation. 11/16 patients were ventilated during sleep only. Symptoms included syncope, dizziness, chest pain, tingling in the left arm, and palpitations. 15/16 patients had recorded ambulatory cardiac monitoring. 5/16 patients were symptomatic without significant sinus pauses. 12/16 patients had implantation of cardiac pacemakers. 9/12 had significant sinus pauses on ambulatory monitoring, and 7/12 patients were symptomatic.

Conclusion: CCHS patients have potential life-threatening arrhythmias requiring cardiac pacemaker implantation. Many of these patients are symptomatic with significant sinus pauses on ambulatory monitoring. However, some symptomatic patients with no significant pauses on ambulatory monitoring may still require cardiac pacemaker implantation.