儿童和青少年神经介导性晕厥的诊断和管理指南（2024年修订版）.docx

REVIEW ARTICLE Guidelines for the diagnosis and treatment of neurally mediated syncope in children and adolescents (revised 2024) Cheng Wang1  · Ying Liao2  · Shuo Wang3  · Hong Tian4  · Min Huang5  · XiangYu Dong6  · Lin Shi7  · YaQi Li7  · JingHui Sun8  · JunBao Du2  · HongFang Jin2,9 · Chinese Pediatric Cardiology Society, Chinese Pediatric Society, Chinese Medical Association; Committee of Pediatric Syncope, College of Pediatricians, Chinese Medical Doctor Association; Pediatric Cardiology Society, Beijing Pediatric Society, Beijing Medical Association; Committee of Pediatric Cardiology, College of Cardiovascular Physicians, Chinese Medical Doctor Association Received: 18 April 2024 / Accepted: 17 May 2024 © The Author(s) 2024 Abstract Background Signifcant progress has been made in the diagnosis and treatment of pediatric syncope since the publication of the “2018 Chinese Pediatric Cardiology Society (CPCS) guideline for diagnosis and treatment of syncope in children and adolescents” (“2018 Edition Guidelines”). Therefore, we have revised and updated it to assist pediatricians in efectively managing children with syncope. Data sources According to the “2018 Edition Guidelines”, the expert groups collected clinical evidence, evaluated preliminary recommendations, and then organized open-ended discussions to form the recommendations. This guideline was developed by reviewing the literature and studies in databases including PubMed, Cochrane, EMBASE, China Biomedical Database, and Chinese Journal Full-text Database up to April 2024. Search terms included “syncope”, “children”, “adolescents”, “diagnosis”, and “treatment.” Results The guidelines were based on the latest global research progress and were evidence-based. The classifcation of syncope etiology, diagnostic procedures, postural tests, such as the active standing test, head-up tilt test, and active sitting test, clinical diagnosis, and individualized treatment for neurally mediated syncope in pediatric population were included. Conclusions The guidelines were updated based on the latest literature. The concepts of sitting tachycardia syndrome and sitting hypertension were introduced and the comorbidities of neurally mediated syncope were emphasized. Some biomarkers used for individualized treatment were underlined. Specifc suggestions were put forward for non-pharmacological therapies as well as the follow-up process. The new guidelines will provide comprehensive guidance and reference for the diagnosis and treatment of neurally mediated syncope in children and adolescents. Keywords Adolescents · Children · Diagnosis · Neurally mediated syncope · Treatment Introduction Syncope is a transient loss of consciousness (TLOC) and inability to maintain the posture caused by transient global cerebral hypoperfusion. It is characterized by a rapid onset, short duration, and spontaneous complete recovery [1–4] (I; C). Syncope, a common disorder in children and adolescents, has an incidence of 17.37% [5], with a higher occurrence in girls than in boys [6] (IIa; B). It accounts for 1%–2% of visits to the emergency department [1]. The pathogenesis, etiology, diagnosis, and treatment of pediatric syncope difer from those in adults. Recurrent syncope can seriously impact the physical and mental health, learning abilities, and quality of life of The members of the group Chinese Pediatric Cardiology Society, Chinese Pediatric Society, Chinese Medical Association; Committee of Pediatric Syncope, College of Pediatricians, Chinese Medical Doctor Association; Pediatric Cardiology Society, Beijing Pediatric Society, Beijing Medical Association; Committee of Pediatric Cardiology, College of Cardiovascular Physicians, Chinese Medical Doctor Association are listed in Acknowledgements. Extended author information available on the last page of the article World Journal of Pediatrics afected children [7, 8] (IIa; A). In some cases, syncope with cardiogenic causes can even pose a risk of sudden death. From 2015 to 2018, the Heart Rhythm Society, the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, the Canadian Cardiovascular Society, the Canadian Pediatric Cardiology Association, and the European Society of Cardiology successively published guidelines or society position statements on the diagnosis and management of syncope and related syndromes [2, 9–11] (I; C). In 2018, professional societies including the Chinese Pediatric Cardiology Society, Chinese Pediatric Society, Chinese Medical Association; Committee of Pediatric Syncope, College of Pediatricians, Chinese Medical Doctor Association; Pediatric Cardiology Society, Beijing Pediatric Society, Beijing Medical Association; Committee of Pediatric Cardiology, College of Cardiovascular Physicians, Chinese Medical Doctor Association released the "2018 Chinese Pediatric Cardiology Society (CPCS) guidelines for diagnosis and treatment of syncope in children and adolescents" (hereafter referred to as the "2018 Edition Guidelines") [1] to promote the standardized diagnosis and treatment of syncope in children and adolescents. In recent years, signifcant progress has been made in the clinical diagnosis and treatment of syncope, especially neurally mediated syncope (NMS) in children and adolescents, including the etiological classifcation of syncope, diagnostic procedures, posture tests, such as the active standing test, the head-up tilt test (HUTT), as well as the active sitting test, clinical diagnosis, and individualized treatment [12–25]. The “Guidelines for the diagnosis and treatment of neurally-mediated syncope in children and adolescents (revised 2024)” were developed based on the "2018 Edition Guidelines" and followed the latest global research advances. However, more large-scale, multi-center, randomized controlled clinical studies are needed to provide a higher level of evidence for the treatment of NMS in children and adolescents [26]. Classes of recommendations and levels of evidence to manage pediatric syncope The classes of recommendations and levels of evidence for the management of pediatric syncope were weighed and graded based on predefned scales (Tables 1, 2) [1, 2] (I; C). The underlying diseases of syncope in children and adolescents The causes of syncope in children and adolescents include NMS, cardiac syncope (CS), and unexplained syncope (UPS) [1]. NMS is the most common cause accounting for 70%–80%, CS accounts for 2%–3%, and UPS accounts for about 20% [7] (I; C). The causes of syncope in children and adolescents are classifed and listed in Table 3. NMS in children and adolescents is characterized by syncopal attacks caused by abnormal refex regulation or dysfunction of the autonomic nervous system, mainly referring to vasovagal syncope (VVS) and postural orthostatic tachycardia syndrome (POTS), which accounts for about 95% of NMS [4, 27–30] (IIa; B). Breath-holding spells in infancy may be a specifc type Table 1 Classes of recommendations for the management of pediatric syncope Classes of recommendations Defnition Suggested wording to use Class I Evidence and/or general agreement that the given treatment or procedure is benefcial, useful and efective Is recommended/indicated Class II Conficting evidence and/or a divergence of opinion about the usefulness/efcacy of the given treatment or procedure   Class IIa Weight of evidence/opinion favors the usefulness/efcacy Should be considered   Class IIb Usefulness/efcacy is less well established by evidence/opinion May be considered Class III Evidence or general agreement that the given treatment or procedure is not useful/efective and in some cases may be harmful Is not recommended Table 2 Levels of evidence for the management of pediatric syncope Level of evidence Source of evidence A Data derived from multiple randomized clinical trials or meta-analyses B Data derived from a single randomized clinical trial or large non-randomized studies C Consensus of opinion of experts and/or small studies, retrospective studies, registries World Journal of Pediatrics of NMS [31, 32] (I; C). In children and adolescents, NMS is often associated with comorbidities [33, 34]. Nearly 30%–40% of children and adolescents with VVS and/or POTS generally also have allergic diseases [35] (IIa; B), and some may also be associated with coagulation disorders [36], but patent foramen ovale may not increase the risk of pediatric syncope [37] (IIa; B). Other common comorbidities include migraines, mental disorders, sleeping disorders, hyperventilation syndrome, chronic fatigue syndrome, joint hypermobility syndrome, and gastrointestinal disorders. Comorbidities may increase the complexity of diagnosis and treatment [38] (IIa; B). CS is mainly caused by abnormal structure or rhythm of the heart. Although CS is a relatively rare cause of pediatric syncope, it is associated with a high risk of sudden death and needs to be diagnosed as early as possible [39] (IIa; B). Other causes of TLOC [7, 40] (IIa; A), including epileptic seizures, metabolic disorders (e.g., hypoglycemia and hypoxemia), poisoning, and psychological pseudosyncope (PPS) [41–43] (IIa; B), can sometimes be misdiagnosed as syncope. These disorders do not produce transient cerebral hypoperfusion, and thus, should be strictly diferentiated from syncope. Diagnosis Diagnostic procedures for pediatric syncope As shown in Fig. 1, the diagnostic procedures comprise three steps [44] (IIa; B). In the frst step, after medical history taking, physical examination, supine and upright blood pressure (BP) measurement, and supine and upright electrocardiogram (ECG) recording, the patients can be divided into three groups: defnite diagnosis, suggestive diagnosis, and UPS [1]. Defnitive diagnosis POTS, orthostatic hypotension (OH), orthostatic hypertension (OHT) [45, 46] (IIa; A), sitting tachycardia syndrome (STS), and sitting hypertension (SHT) [47, 48] (IIa; B) can be indicated by the history of symptoms of orthostatic intolerance (OI) or sitting intolerance. A diagnosis can be confrmed when patients with typical symptoms have a normal ECG and a positive result in an active standing test, HUTT, or active sitting test [49–56] (IIa; B). Situational syncope (SS) is defned as syncope in specifc situations, such as micturition, defecation, bathing, swallowing, cough, postdinner, singing, teeth brushing, and hair grooming [57, 58] (IIa; B). Drug-induced syncope (determined through medication history) can be diagnosed by typical history. Suggestive diagnosis The patients with suggestive diagnosis after the frst step, as seen in Fig. 1, need further laboratory investigations in step 2. In step 2, cardiomyopathy, pulmonary hypertension, cyanotic congenital heart disease, and some types of arrhythmias can be suspected according to the clues from history, physical examination, and ECG fndings. For example, onset in infancy or early childhood, exercise-induced events [59] (IIa; B), family history of genetic heart disease or sudden death, and abnormal ECG fndings can suggest CS, with the strongest clues provided by exercise-induced syncope and abnormal ECG fndings [60, 61]. For such patients, further examinations are needed to ensure the diagnosis, such as repetitive ECG, Holter ECG, implanted loop recorder (ILR) [62] (IIa; B), exercise test, intracardial electrophysiology, angiography, cardiovascular imaging, screening of metabolic disorder or genetic tests, based on the specifc situation [46, 63] (IIa; B). Unexplained diagnosis In step 3, for patients whose diagnosis cannot be confrmed or indicated by detailed medical history, physical examination, supine BP, and ECG measurements [48] (IIa; A), if the symptoms occur more than once and the characteristics of the attacks suggest NMS, postural tests such as the active standing test, HUTT [9, 64–66] (IIa; B), and active sitting test [47, 48] (IIa; A) can be performed. These tests may help in diagnosing NMS and determining its hemodynamic type. If a defnite diagnosis cannot be achieved even after the above steps are taken, a re-evaluation is needed. This includes history-retaking, physical re-examination, and further laboratory examinations. Moreover, assessment by associated specialists such as neurologists or psychiatrists should be considered when necessary. Table 3 Classifcation of syncope in children and adolescents Classes Underlying diseases and associated syndrome Neurally mediated syncope Vasovagal syncope      Vasoinhibitory type      Cardioinhibitory type      Mixed type Postural orthostatic tachycardia syndrome Orthostatic hypotension Orthostatic hypertension Sitting tachycardia syndrome Sitting hypertension Situational syncope Carotid sinus syndrome Cardiac syncope Arrhythmia Structural cardiac diseases, including cardiomyopathy, etc. Unexplained syncope World Journal of Pediatrics Methodology of postural tests Active standing test The active standing test can be performed to screen for underlying causes of OI in children. It has no absolute contraindications. The protocol First, the children are asked to lay supine for 10–30  minutes to obtain supine heart rate (HR), BP, and ECG recordings. Then, the children are told to actively stand for another 10 minutes, simultaneously monitoring the above parameters [65–67] (IIa; A). Clinical comments During the active standing test, the children should be closely observed to determine whether they have presyncope symptoms or even syncope, and the test can help diagnose POTS [66, 67], OH [66, 68], or OHT [66, 69] (IIa; B). Here, the presyncope consists of symptoms including dizziness, headache, chest tightness, palpitations, Fig. 1 Diagnostic procedure for pediatric syncope. ECG electrocardiogram, SS situational syncope, POTS postural orthostatic tachycardia syndrome, OH orthostatic hypotension, OHT orthostatic hypertension, STS sitting tachycardia syndrome, SHT sitting hypertension, CHD congenital heart disease, HUTT head-up tilt test, VVS vasovagal syncope, VVS-VI vasovagal syncope vasoinhibitory type, VVS-CI vasovagal syncope cardioinhibitory type, VVS-M vasovagal syncope mixed type. a For children with normal physical examination and normal routine ECG fndings, ECG is generally not helpful in determining possible reasons. For children with possible structural heart defects after medical history, physical examination, and routine ECG. ECG is a screening tool to detect abnormal cardiac structures or functions; b Holter ECG is a common test to determine the cause of syncope. However, because syncope is unpredictable, regular monitoring for only 24  hours makes it difcult to confrm or thoroughly rule out the association between arrhythmia and syncope. When diagnosing the cause of syncope, comprehensive judgment should be made together with history-taking and other tests. The possible reasons include asymptomatic sinus bradycardia, atrioventricular block, and endless supraventricular or ventricular tachy