Impact of Heart Transplantation on Cheyne-Stokes Respiration in a Child

Cheyne-stokes respiration in children with heart failure

Cheyne-Stokes respiration (CSA-CSR) is a form of central sleep apnea characterized by alternating periods of hyperventilation and central apneas or hypopneas. CSA-CSR develops following a cardiac insult resulting in a compensatory increase in sympathetic activity, which in susceptible patients causes hyperventilation and destabilizes respiratory control. The physiological changes that occur in CSA-CSR include hyperventilation, a reduced blood gas buffering capacity, and circulatory delay. In adults, 25% to 50% of patients with heart failure are reported to have CSA-CSR. The development of CSA-CSR in this group of patients is considered a poor prognostic sign. The prevalence, progression, and treatment outcomes of CSA-CSR in children remain unclear with only 11 children being described in the literature. The lack of data is possibly not due to the paucity of children with severe heart failure and CSA-CSR but because they may be under-recognized, compounded by the absence of routine polysomnographic assessment of children with moderate to severe heart failure. Building on much broader experience in the diagnosis and management of CSA-CSR in adult sleep medicine and our limited experience in a pediatric quaternary center, this paper will discuss the prevalence of CSA-CSR, its' treatment options, outcomes in children, and the potential future direction for research in this understudied area of pediatric sleep medicine.

Continuous positive airway pressure improves work of breathing in pediatric chronic heart failure

BACKGROUND

Sleep disordered breathing (SDB) is common in adults with chronic heart failure (CHF), but its prevalence in children remains unclear. Continuous positive airway pressure (CPAP) is the treatment of SDB but deleterious hemodynamic effects have been reported.

METHODS

We prospectively analyzed SDB in children with CHF and the effect of CPAP on work of breathing (WOB) and cardiac index (CI). Children aged 6 months to 18 years old with CHF due to: 1) dilated cardiomyopathy (DM) with an ejection fraction < 45%, 2) functional single ventricle (SV) or 3) aortic or mitral valve disease awaiting surgery (VD) were eligible for the study. A polysomnography (PSG), measurement of WOB and CI during spontaneous breathing (SB) and CPAP (6, 8 and 10 cmH₂O) were performed.

RESULTS

Thirty patients with mean age of 6.4 ± 5 years were included (16 DM 16, 10 SV, 4 LV). Twenty (73%) patients had a normal sleep efficiency. Median apnoeas hypopnea index (IAH) was within normal range at 1.6 events/h (0, 14) events/hour. Only one patient had central sleep apnoeas, none had Cheyne-Stokes respiration, and 3 patients had an obstructive AHI between 5 and 10 events/hour. Optimal CPAP level decreased WOB (p = 0.05) and respiratory rate (p = 0.01).

CONCLUSIONS

Severe SDB was uncommon in children with CHF. However, CPAP may be beneficial by decreasing WOB and respiratory rate without deleterious effects on CI.

Sleep-disordered breathing in pediatric heart transplant recipients

BACKGROUND

Sleep-disordered breathing is commonly found in adults with heart failure both before and after HTx. Untreated sleep-disordered breathing post-transplant has been linked to late graft dysfunction, reduced quality of life, and increased morbidity. Sleep-disordered breathing has not been investigated in pediatric HTx recipients.

METHODS

We conducted retrospective review of patients <21yo who underwent primary HTx at our center from 2009 to 2019 to describe clinical characteristics, cardiac history, and PSG results.

RESULTS

One hundred and fifty patients were included; 60% had congenital heart disease, and 40% had cardiomyopathy. Fifty patients had PSG performed at median age of 6.1 years. Forty-one were referred for symptoms of sleep-disordered breathing. Obstructive sleep apnea was diagnosed in 45 patients and central sleep apnea in 3 patients. Of those with first PSG post-transplant (n = 36), median AHI was 9.1/h, and 19 (53%) were diagnosed with moderate or severe sleep apnea. Patients diagnosed with obstructive sleep apnea on PSG had more post-transplant ventilator days (median 3 vs 2 days, P < .05) and longer post-transplant lengths of stay (median 28 vs 22 days, P < .05).

CONCLUSIONS

In this single-center cohort of pediatric HTx recipients, sleep-disordered breathing was common and associated with longer peri-transplant respiratory support and length of stay. Given the high incidence of moderate and severe OSA detected in this population, clinicians should regularly screen for SDB and consider PSG testing more frequently in children who have undergone HTx. Further study into the long-term impact of sleep-disordered breathing in pediatric HTx recipients is needed.