Incidence and Risk Factors of Immediate Hypersensitivity Reactions and Immunisation Stress-related Responses with COVID-19 mRNA Vaccine

Background: With the implementation of mass vaccination campaigns against COVID 19, the safety of vaccine needs to be evaluated. Objective: We aimed to assess the incidence and risk factors for immediate hypersensitivity reactions (IHSR) and immunisation stress related responses (ISRR) with the Moderna COVID 19 vaccine. Methods: This nested case control study included recipients who received the Moderna vaccine at a mass vaccination centre, Japan. Recipients with IHSR and ISRR were designated as cases 1 and 2, respectively. Controls 1 and 2 were selected from recipients without IHSR or ISRR and matched (1:4) with cases 1 and cases 2, respectively. Conditional logistic regression analysis was used to identify risk factors associated with IHSR and ISRR. Results: Of the 614,151 vaccine recipients who received 1,201,688 vaccine doses, 306 recipients (cases 1) and 2,478 recipients (cases 2) showed 318 events of IHSR and 2,558 events of ISRR, respectively. The incidence rates per million doses were estimated as IHSR: 266 cases, ISRR: 2,129 cases, anaphylaxis: 2 cases, and vasovagal syncope: 72 cases. Risk factors associated with IHSR included female, asthma, atopic dermatitis, thyroid diseases, and history of allergy; for ISRR, they were younger age, female, asthma, thyroid diseases, mental disorders, and a history of allergy and vasovagal reflex. Conclusion: In the mass vaccination settings, the Moderna vaccine can be used safely owing to the low incidence rates of IHSR and anaphylaxis. However, providers should beware of the occurrence of ISRR. Risk factor identification may contribute to the stratification of high risk recipients for IHSR and ISRR.

Autonomic Dysfunction in Autism Spectrum Disorder

Background: There have been previous reports of enhanced sympathoexcitation in autism spectrum disorder (ASD). However, there has been no formal investigation of autonomic dysfunction in ASD. Also, the joint hypermobile form of Ehlers-Danlos syndrome (hE-DS) that maybe overrepresented in ASD and orthostatic related autonomic dysfunction. This study examined the comorbidity of ASD, autonomic dysfunction and hE-DS in two UK autonomic national referral centers. Proven, documented and globally accepted clinical autonomic investigations were used to assess neuro-cardiovascular autonomic function in a cohort of ASD subjects and in age-matched healthy controls.Methods: Clinical data from 28 referrals with a confirmed diagnosis of ASD over a 10-year period were compared with 19 age-matched healthy controls. Autonomic function was determined using methods established in the centers previously described in detail.Results: 20/28 ASD had a diagnosed autonomic condition; 9 had the postural tachycardia syndrome (PoTS), 4 PoTS and vasovagal syncope (VVS), 3 experienced presyncope, 1 essential hyperhidrosis, 1 orthostatic hypotension, 1 VVS alone and 1 a combination of PoTS, VVS and essential hyperhidrosis. 16/20 ASD with autonomic dysfunction had hE-DS. In ASD, basal heart rate and responses to orthostatic tests of autonomic function were elevated, supporting previous findings of increased sympathoexcitation. However, sympathetic vasoconstriction was impaired in ASD.Conclusion: Intermittent neuro-cardiovascular autonomic dysfunction affecting heart rate and blood pressure was over-represented in ASD. There is a strong association with hE-DS. Autonomic dysfunction may further impair quality of life in ASD, particularly in those unable to adequately express their experience of autonomic symptoms.

Sex and age impact prevalence and symptoms of vasovagal syncope: Implications for accurate diagnosis

Syncope is characterized by the transient loss of consciousness followed by spontaneous recovery. The mechanism which underlies this condition is reduced blood flow to the brain [1]. Vasovagal syncope, often termed reflex syncope, is the most common type of syncope [1]. Vasovagal Syncope is caused by the abnormal autonomic reflex to certain stimuli such as pain, micturition/defecation, fear, seeing blood, etc., which results in vasodilation and often times, bradycardia [1].

Clinical Characteristics And Prognosis of Vasovagal Syncope With Sinus Arrest In Children

The aim of this study was to analyze the clinical characteristics and prognosis of vasovagal syncope(VVS) with sinus arrest in children. From July 2017 to October 2020, cases of VVS with sinus arrest were recruited from patients diagnosed as VVS in our department. The clinical data, the results of the head-up tilt testing (HUTT), and follow-up information were analyzed. 223 patients were diagnosed as VVS during the time, and 10 cases of VVS with sinus arrest were recruited, who had a median age of 9.5 years（interquartile range: 6.8 to 10.4 years), a gender ratio of 1:1, and median sinus arrest time of 7.7s(range: 3.39 to 19s). These patients were given oral rehydration salts and orthostatic training, as well as 2 children treated with metoprolol and 5 children with sertraline hydrochloride. No child was implanted with pacemakers. During a median of 26 months of follow-up (interquartile range: 21 to 33 months), only one of the children had once syncope episode, three children had 1~4 times of prodromal symptoms. Conclusion The present research most crucial finding was that VVS patients with sinus arrest in children were younger than ordinary pediatric VVS patients. Oral rehydration salts(ORS) and autonomic nerve function exercise may improve clinical symptoms in children with VVS accompanied by sinus arrest. Pacemakers for VVS with sinus arrest in children should be cautious.

Clinical Characteristics of Personality and Conduct Disorders in Child Patients With Vasovagal Syncope: A Clinical Case-Control Study

Objective: To analyze the clinical characteristics of abnormal personality and conduct disorders (CDs) in pediatric patients with vasovagal syncope (VVS).Methods: In this study, we recruited patients diagnosed with VVS at Children's Heart Center from January 2018 to December 2020. Healthy children were recruited as controls. The Eysenck Personality Questionnaire-Child edition (EPQ-C) and Achenbach Child Behavior Checklist (CBCL) were used for the assessment.Results: One hundred and fifty-one VVS patients and 151 healthy controls were included in this study. Compared with the control group, patients in the VVS group had a higher incidence of abnormal personality and were more prone to suffer from CDs. Moreover, pediatric patients with VVS suffered more events of syncope recurrence if they had CDs.Conclusion: Abnormal personality and CDs are common clinical characteristics in pediatric patients with VVS.

Evaluation and Management of Reflex Vasovagal Syncope—A Review

Syncope is a symptom that is commonly encountered in the practice and may point to a cardiac or neurological diagnosis. The evaluation of syncope rests on a thorough clinical evaluation, aided by electrocardiogram (ECG) findings, followed by risk stratification of the particular case. Once high-risk factors have been ruled out, the patient can be further diagnosed as having a reflex syncope (RS), orthostatic hypotension, or cardiac syncope based on specific clues. If the initial evaluation is not confirmatory various diagnostic tests may be used to guide further management (eg, long-term ECG monitoring, tilt table testing, etc). The management should be based on the overall profile of the patient and not only on any single test. In this review, we discuss the evaluation of a patient with RS and give an overview of treatments available for the patients.