[Autonomic dysfunction and cardiac arrhythmia in patients with obstructive and central sleep apnea]

Asystole in a young child with tetrahydrocannabinol overdose: a case report and review of literature

Introduction

The association between Δ8-tetrahydrocannabinol (THC) and cardiac dysrhythmia has not been well described in children. Asystole, while consistent with reports of severe bradycardia and apnea in children, is uncommonly described in the current literature. We present the first pediatric case of asystole and apnea following THC ingestion.

Case

A 7-year-old male presented to the emergency department (ED) after his mother noticed he was lethargic 3-4 h after accidental ingestion of five 15 mg (total of 75 mg) Δ8-THC gummies. Upon arrival, he was vitally stable and well-appearing. He received maintenance intravenous fluids. Approximately 7 h after initial ingestion, he experienced a >15-s episode of asystole and apnea on telemetry requiring sternal rub to awaken. This was followed by bradycardia (60 beats per minute range) which resolved with 0.1 mg glycopyrrolate. He was admitted to the PICU, drowsy but arousable with stable vitals. After an uneventful 24-h (post-ingestion) PICU observation, he was discharged home in stable condition.

Discussion

To our knowledge, this is the first reported pediatric case of THC-induced asystole. The etiology of asystole may be attributed to direct vagal stimulation of THC or respiratory depression. The typical recommended observation time after potential toxicity is 3-6 h after children have returned to their physiological and behavioral baseline. Our patient was clinically stable with no concern for respiratory depression or cardiac dysrhythmia yet experienced an asystolic pause with apnea 7 h after initial ingestion.

Conclusion

Our case demonstrates that asystole and apnea may occur in pediatric patients following large THC ingestions and those symptoms can appear late outside of the currently recommended observation period.

Effect of Continuous Positive Airway Pressure on Blood Pressure in Patients with Resistant Hypertension and Obstructive Sleep Apnea: An Updated Meta-analysis

PURPOSE OF REVIEW

The effect of continuous positive airway pressure (CPAP) on resistant hypertension in patients at high risk with obstructive sleep apnea (OSA) needs further investigation. We aimed to determine the effect of CPAP on blood pressure in patients with resistant hypertension and OSA. Databases including PubMed, EMBASE, MEDLINE, the Cochrane Library, and CMB were searched. Data were pooled using a random-effects or fixed-effects model to derive weighted mean differences (WMDs) and 95% confidence intervals (CIs).

RECENT FINDINGS

A total of 12 trials and 718 participants were included. Compared with control, CPAP significantly reduced 24-h systolic blood pressure (SBP) (WMD: - 5.92 mmHg [ - 8.72, - 3.11]; P＜0.001), 24-h diastolic blood pressure (DBP) (WMD: - 4.44 mmHg [- 6.26 , - 2.62]; P  ＜0.001),   daytime SBP (WMD: - 5.76 mmHg [ - 9.16,  - 2.36]; P ＜0.001),  daytime DBP (WMD: - 3.92 mmHg [- 5.55,  - 2.30];  nighttime SBP (WMD: - 4.87 mmHg [ - 7.96 ,  - 1.78]; P = 0.002), and nighttime DBP (WMD: - 2.05 mmHg [- 2.99,  - 1.11]; P＜0.001) in patients with resistant hypertension and OSA. CPAP improved the blood pressure both in the short (＜3 months) and long term (≥ 3  months). No significant impact on mean heart rate was noted (WMD: -2.76 beats per min [- 7.50, 1.97]; P = 0.25). CPAP treatment was associated with BP reduction in patients with resistant hypertension and OSA.

Pathophysiological Mechanisms to Review Association of Atrial Fibrillation in Heart Failure With Obstructive Sleep Apnea

Sleep-disordered breathing (SDB) comprising obstructive sleep apnea (OSA) is found in more than half of patients with heart failure (HF) and may have negative impacts on cardiovascular function. Increased atherosclerotic cardiovascular disease and the development of coronary events and congestive heart failure are associated with OSA. It is associated with a substandard quality of life, increased hospitalizations, and a poor prognosis. Despite its association with severe cardiovascular morbidity and mortality, the condition is frequently underdiagnosed. The substantial clinical evidence has established OSA as an independent risk factor for bradyarrhythmias and tachyarrhythmias in the last decade. The mechanisms which lead to such arrhythmias are uncertain. In short, OSA patients have a significantly elevated risk of HF and atrial fibrillation (AF). The direct correlation between HF, SDB, and cardiac arrhythmias has been poorly understood. The purpose of this study is to get a better understanding of the relation between AF, OSA, and HF by focusing on the pathophysiological mechanisms underlying these conditions. Therefore, we searched for articles to support our association in PubMed and Google Scholar databases.

Cardiac arrhythmias and sleep-disordered breathing in patients with heart failure

The relationship between heart failure (HF), sleep-disordered breathing and cardiac arrhythmias is complex and poorly understood. Whereas the frequency of predominantly obstructive sleep apnea in HF patients is low and similar or moderately higher to that observed in the general population, central sleep apnea (CSA) has been observed in approximately 50% of HF patients, depending on the methods used to detect CSA and patient selection. Despite this high prevalence, it is still unclear whether CSA is merely a marker or an independent risk factor for an adverse prognosis in HF patients and whether CSA is associated with an increased risk for supraventricular as well as ventricular arrhythmias in HF patients. The current review focuses on the relationship between CSA and atrial fibrillation as the most common atrial arrhythmia in HF patients, and on the relationship between CSA and ventricular tachycardia and ventricular fibrillation as the most frequent cause of sudden cardiac death in HF patients.