Echocardiographic parameters in adolescents with sleep-related breathing disorders

Echocardiographic findings in children with obstructive sleep apnea: A systematic review

OBJECTIVE

To systematically review the incidence of cardiac abnormalities in pediatric patients with obstructive sleep apnea (OSA) in order to assess the utility of preoperative echocardiographic evaluation for patients undergoing surgery.

STUDY DESIGN

A systematic literature review was performed following the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. Data sources were searched from January 1, 1980 to March 25, 2020. Studies that examined echocardiographic findings and polysomnographic data for patients between birth and 18 years of age with polysomnogram-confirmed OSA were included. Studies that included patients with preexisting cardiac, metabolic, or hematologic disorders that could affect hemodynamic parameters were excluded. Included studies were assessed for quality and risk of bias using the U.S. National Institute of Health's Quality Assessment Tools.

RESULTS

Thirteen studies met inclusion criteria. Five studies were categorized as high risk of bias, three were categorized as medium risk, and five were categorized as low risk. Study design varied considerably between studies, including heterogeneous classifications of OSA severity, discrepant reporting of echocardiographic parameters, and differing estimations of pulmonary hemodynamics. Significant disagreement regarding the effect of OSA on cardiac function was found between all included studies.

CONCLUSION

Data demonstrating significant associations between OSA and cardiac abnormalities in children is inconsistent. Echocardiographic abnormalities are inconsistently found and, when present, their clinical significance remains poorly understood. Assessing the utility of preoperative echocardiography in children with OSA requires further investigation with prospective studies utilizing standardized classifications of OSA severity, reporting of echocardiographic parameters, and estimations of pulmonary hemodynamics.

Echocardiographic screening in children with very severe obstructive sleep apnea

OBJECTIVE

(i) To determine the prevalence of echocardiographic abnormalities in children with very severe OSA defined by an apnea hypopnea index (AHI) ≥ 30 events/hour. (ii) To test the hypothesis that polysomnographic parameters predict echocardiographic variables in this population.

METHODS

Children aged 1-17 years presenting with polysomnography demonstrating an AHI ≥30 and referred for pre-operative echocardiography performed within the 6 months prior to tonsillectomy and adenoidectomy (T&A), over a two-year period (January 1, 2016 to December 31, 2018) were evaluated. The exclusion criteria were the presence of (i) unrepaired congenital cardiac disease, (ii) tracheostomy, (iii) poorly controlled asthma, or (iv) neuromuscular disorder. The prevalence of echocardiographic abnormalities was determined for the study population. The impact of the severity of OSA on echocardiographic parameters was evaluated using Student's t-test. The relationships between polysomnographic variables and biventricular function as well as pulmonary hemodynamics were measured. A penalized regression model was used to identify the contributions of polysomnographic variables to each echocardiographic parameter by mitigating inter-variable relationships. P < .05 was considered significant.

RESULTS

Eighty-nine children were screened, of whom 47 were included for analysis. The mean age was 68.8 months [95% confidence interval, 56.0 to 81.6]. Thirty-three (70.2%) were boys. Twenty (42.6%) were obese. All children had normal echocardiograms. The differences in echocardiographic variables between children grouped by the severity of OSA were not statistically significant (P: 0.18-0.98). Polysomnographic variables predicted only 4 out of 13 studied echocardiographic parameters.

CONCLUSIONS

Pre-operative echocardiography did not identify significant abnormalities in children with very severe OSA. Majority of the echocardiographic variables were not predicted by polysomnographic parameters. This study demonstrates the limited benefit associated with routine echocardiographic screening of children with very severe OSA solely based on polysomnographic indices.

Sleep and the Cardiovascular System in Children

Subspecialty pediatric practice provides comprehensive medical care for a range of ages, from premature infants to children, and often includes adults with complex medical and surgical issues that warrant multidisciplinary care. Normal physiologic variations involving different body systems occur during sleep and these vary with age, stage of sleep, and underlying health conditions. This article is a concise review of the cardiovascular (CV) physiology and pathophysiology in children, sleep-disordered breathing (SDB) contributing to CV morbidity, congenital and acquired CV pathology resulting in SDB, and the relationship between SDB and CV morbidity in different clinical syndromes and systemic diseases in the expanded pediatric population.

A systematic review and meta-analysis of cohort studies of echocardiographic findings in OSA children after adenotonsilectomy

CONTEXT

There is evidence that OSA in children can be associated with acute and chronic effects on the cardiovascular system due to repetitive episodes of apnea and hypoxemia.

OBJECTIVE

To assess whether there is an association between OSA and echocardiographic findings in children and whether that association persists after adenotonsillectomy.

DATA SOURCES

A literature search was conducted based on PUBMED, EMBASE and LILACS.

STUDY SELECTION

Children with OSA and children who did not have OSA, who were aged ≤12 years.

DATA EXTRACTION

Two reviewers extracted data independently; the risk of bias was assessed by examining the selected sample, the recruitment method, completeness of follow up, and blinding.

RESULTS

Seven studies met all the inclusion criteria and methodological requirements. There was a significant difference with elevated mean pulmonary arterial pressure levels in OSA participants compared to those without OSA at preoperative assessment [mean difference (MD) 8.67; confidential interval (CI) 95% 6.09, 11.25]. OSA participants showed a statistically significant increased interventricular septum (IVS) thickness (mm) [MD 0.60; CI 95% 0.09, 1.11]; and right ventricular (RV) dimension (cm/m) [MD 0.19; CI 95% 0.10, 0.28]. There was also a significant increase in right ventricular (RV) dimension (cm/m) [MD 0.10; CI 95% 0.05, 0.14] in OSA children.

CONCLUSION

There is moderate quality evidence regarding possible association between OSA and right heart repercussions. More prognosis studies are needed, to allow the combination of results in a meta-analysis.

Left ventricular hypertrophy and diastolic dysfunction in children with sickle cell disease are related to asleep and waking oxygen desaturation

Premature death and cardiac abnormalities are described in individuals with sickle cell disease (SCD), but the mechanisms are not well characterized. We tested the hypothesis that cardiac abnormalities in children with SCD are related to sleep-disordered breathing. We enrolled 44 children with SCD (mean age, 10.1 years; range, 4-18 years) in an observational study. Standard and tissue Doppler echocardiography, waking oxygen saturation averaged over 5 minutes, and overnight polysomnography were obtained in participants, each within 7 days. Eccentric left ventricular (LV) hypertrophy was present in 46% of our cohort. After multivariable adjustment, LV mass index was inversely related to average asleep and waking oxygen saturation. For every 1% drop in the average asleep oxygen saturation, there was a 2.1 g/m(2.7) increase in LV mass index. LV diastolic dysfunction, as measured by the E/E' ratio, was present in our subjects and was also associated with low oxygen saturation (sleep or waking). Elevated tricuspid regurgitant velocity (> or = 2.5 m/sec), a measure of pulmonary hypertension, was not predicted by either oxygen saturation or sleep variables with multivariable logistic regression analysis. These data provide evidence that low asleep and waking oxygen saturations are associated with LV abnormalities in children with SCD.

Obstructive sleep breathing disorders

Obstructive sleep apnea (OSA) is increasingly recognized in children. There is accumulating robust evidence to support early diagnosis and treatment of this condition. The purpose of this review is to provide an update on the epidemiology, clinical features, complications, and treatment of childhood OSA. The authors have also proposed an easy-to-follow flowchart on the management of children with snoring or sleep disturbance for clinical use by busy pediatricians.

Blood pressure associated with sleep-disordered breathing in a population sample of children

The current criteria for sleep-disordered breathing (SDB) in children are not based on a clinically relevant outcome. The purpose of this study was to assess the association of blood pressure with SDB in a random sample of the local elementary school children (kindergarten through grade 5) using a 2-phased strategy. During phase 1, a brief questionnaire was completed for all of the children (N=5740) with a response rate of 78.5%. During phase 2, 700 randomly selected children from phase 1 with a response rate of 70.0% were assessed with a full polysomnograph and a history/physical, including an ECG; ear, nose, and throat; and pulmonary evaluation. We observed a significantly elevated systolic blood pressure associated with the apnea hypopnea index (AHI): AHI >or=1 (2.9 mm Hg); AHI >or=3 (7.1 mm Hg); and AHI >or=5 (12.9 mm Hg). The SDB and blood pressure association remained significant after adjusting for age, sex, race, body mass index percentile or waist circumference, sleep efficiency, percentage of rapid eye movement sleep, and snoring. In addition, older age, body mass index percentile, waist circumference, and snoring were significantly associated with blood pressure, independent of SDB. Based on these findings, our study suggests that SDB is significantly associated with higher levels of systolic blood pressure in children aged 5 to 12 years even after adjusting for the various confounding factors. Clinically, the data support the threshold of AHI >or=5 for the initiation of treatment for SDB. Additional research is indicated to assess the efficacy of SDB treatment on reducing blood pressure.

Cardiovascular Changes in Children with Snoring and Obstructive Sleep Apnoea

Introduction: Adults with obstructive sleep apnoea (OSA) are well documented to be at high risk for cardiovascular abnormalities. Growing evidence suggests that OSA is also associated with cardiovascular consequences in children. The purpose of this review is to examine the available data on this association in children. Methods: Primary studies were extracted from a MEDLINE search limited to those published between 1970 and 2008. The keywords used included child, sleep disordered breathing, sleep apnoea, snoring, blood pressure and hearts. The relevant articles were selected by consensus between 2 authors. Results: The results suggested that OSA was consistently associated with hypertension. Meta-analysis of risk of hypertension in those with high apnoea-hypopnoea index was undertaken. A combined odds ratio equal to 3.15 was found (95% confidence interval, 2.01 to 4.93). There was evidence for increased sympathetic activation, decreased arterial distensibility and ventricular hypertrophy in children with OSA. Conclusion: Childhood OSA is associated with blood pressure dysregulation. The association of OSA with other cardiovascular morbidities requires further study in view of the limited data available currently. Key words: Atherosclerosis, Child, Hypertension

Sleep disordered breathing in pediatric patients with tetralogy of Fallot

Adverse effects on the pulmonary circulation in obstructive sleep disordered breathing (SDB) may place children with heart lesions affecting the right ventricle at increased risk for morbidity and mortality. We examined the distribution and effects of SDB in pediatric patients with tetralogy of Fallot (TOF). Families of 37 pediatric patients with TOF completed a survey of cardiac symptoms and school performance as well as a Pediatric Sleep Questionnaire (PSQ), a validated questionnaire for the screening of SDB in children 2-18 years of age. Medical records were reviewed for growth parameters, medical history, and most recent electrocardiogram (ECG) findings. Data from patients with SDB (PSQ score > or = 8, n = 14) were compared to data from patients without SDB (PSQ score < 8; n = 23). The prevalence of SDB in this population (38%) was significantly higher than the published prevalence of 5% in a healthy general pediatric population (p < 0.001). No significant difference was found in age, gender, or age and sex standardized body mass index between patients with or without SDB. No difference was seen in medication use or timing of surgical repair, whether primary or palliative. Patients with SDB had a significantly higher cardiac symptom score (p = 0.01) and increasing PSQ scores correlated with worsening cardiac symptom scores (p = 0.006). Increasing PSQ scores also correlated with worsening school performance (p = 0.001). No differences were seen in ECG data. The screened prevalence of SDB in the pediatric population with TOF is higher than in the general population; patients with TOF and SDB are more likely to have worse cardiac symptoms and poor school performance.

Childhood sleep-disordered breathing and its implications for cardiac and vascular diseases

OBJECTIVE

To systematically evaluate the recent literature regarding the relationship between childhood sleep-disordered breathing (SDB)/obstructive sleep apnoea (OSA) and cardiovascular diseases in children.

METHODS

The literature about SDB/OSA and blood pressure, sympathetic activation, arterial distensibility, ventricular hypertrophy and insulin resistance were studied. Meta-analysis of risk of hypertension and high apnoea-hyponoea index were performed to calculate the combined odds ratio and it is equal to 2.93 (95% CI = 1.18-7.29).

RESULTS

The results suggest a significant association between SDB/OSA and hypertension. However, the data are not adequate to draw firm conclusion although evidences were emerging to suggest that SDB/OSA affects blood pressure in either directions in children. Limited evidences also suggest that SDB/OSA is associated with increased sympathetic activation, decreased arterial distensibility and ventricular hypertrophy.

CONCLUSIONS

There is now increasing but not adequate evidence that childhood SDB/OSA is associated with detectable cardiovascular abnormalities.

Natural history of snoring and obstructive sleep apnea in Thai school-age children

In 1999, a survey was carried out in 1,008 Thai children aged 7 years, which found that 85 (8.5%) children were habitual snorers, and 7 (0.69%) children had mild obstructive sleep apnea syndrome (OSAS). Since the natural history of snoring and untreated mild OSAS is still largely unknown, this study was undertaken in 2002 in the same group of children to determine the natural history of snoring and OSAS. Questionnaires, consisting of questions about snoring, were sent to the parents of the 1,008 children. Polysomnography was performed in 1) the 7 children who had OSAS in the previous survey, and 2) other habitual snorers who had sleep-related symptoms in this survey. Seventy-five percent of the questionnaires were returned. The prevalence of habitual snoring had decreased slightly, from 8.5% in 1999 to 6.9% in 2002. Sixty-five percent of the children who had snored habitually in the previous survey no longer did so, whereas 4.5% of the children who previously never snored or snored sometimes had become habitual snorers. Of the 7 children who had OSAS previously, 5 had persistent snoring, and polysomnographic studies revealed more severe OSAS, with an apnea-hypopnea index (AHI) of 1.5-9.2 per hour of sleep. Five children were newly diagnosed with OSAS in this survey, with an AHI of 1.5-7.5. The overall prevalence of OSAS in this survey was 10/755 (1.3%). In conclusion, 65% of children who snored habitually no longer did so when they got older, while 9% of children had developed OSAS. We suggest that regular follow-up in children with habitual snoring may be needed, and additional research is required to determine the indications for polysomnography and neurobehavioral and cardiovascular assessment. We also showed that children with mild OSAS could develop more severe disease if left untreated, suggesting that deferment of treatment may have negative consequences.