The clinical characteristics of situational syncope in children and adults undergoing head-up tilt testing

The clinical characteristics and response to head-up tilt test of patients with micturition syncope: single-center experience in China

OBJECTIVE

This study compared clinical characteristics and response to head-up tilt test (HUTT) between micturition syncope (MS) and typical vasovagal syncope (VVS).

METHODS

Consecutive patients who underwent nitroglycerin-potentiated HUTT were retrospectively dichotomized into two groups: those with a history of MS and those with a history of VVS. The patients with MS were further subdivided into patients with MS alone and with MS and at least one episode of VVS.

RESULTS

A total of 2637 patients were enrolled: 204 had MS (MS alone in 103 and MS+VVS in 101), and 216 had typical VVS. Patients with MS were older (38.6 ± 13.1 vs. 36.3 ± 18.5, p = 0003) and more likely to be male (66.2% vs. 48.1%, p < 0.001). Multivariable analysis revealed that smoking habit (odds ratio [OR] 2.16, p < 0.0001), history of traumatic syncope (OR 2.24, p = 0.0001), and drinking alcohol before syncope (OR 2.63, p < 0.0001) were independently associated with MS. HUTT was positive in 141 (69.1%) patients with MS and in 144 (66.7%) patients with VVS (p = 0.592). Patients with MS showed more mixed (46.1% vs. 28.2%, p < 0.001) and vasodepressor forms (15.2% vs. 7.9%, p = 0.013) and fewer cardioinhibitory responses than others (7.4% vs. 30.6%, p < 0.001).

CONCLUSIONS

Compared with VVS, patients with MS have different clinical characteristics, and drinking alcohol was an important precipitating factor for MS. The positivity rate of HUTT is high and similar to that of VVS, although patients with MS show a higher prevalence of hypotensive responses.

The impact of school periods and long holiday periods on the occurrence of neurally mediated syncope in children

OBJECTIVE

To explore the impact of school periods and long holiday periods on the occurrence of neurally mediated syncope (NMS) in children.

METHODS

A retrospective analysis was conducted on 262 children with NMS. The children were aged 4-17 years, 119 males. 244 cases were diagnosed as vasovagal syncope, and 18 cases as postural orthostatic tachycardia syndrome. The data on the age, sex, syncope triggers, hemodynamic types, family history of syncope of children with syncope during long holiday periods group (n = 68) and school periods group (n = 194) were compared.

RESULTS

(1) Incidence of syncope: The incidence of syncope during school periods (74.05%) was higher than that during long holiday periods (25.95%). (2) Comparison of sex and triggers: The constituent ratio of females with syncope during school periods was higher than that of males (P < 0.05). Among the triggers, the proportion of sudden postural change during long holiday periods was higher than that during school periods (26.47% vs. 21.13%, P < 0.05). (3) Univariate analysis: Situational syncope was a potential protective factor when syncope occurred during school periods (OR 0.23, 95%CI 0.07-0.76, P < 0.05), and being female was a potential risk factor (OR 1.92, 95%CI 1.10-3.35, P < 0.05). (4) Comparison of multiple models: In the risk of syncope occurring during school periods, situational syncope reduced the risk by 79% compared with no trigger, and being female increased the risk by 78% compared with being male.

CONCLUSIONS

The occurrence of NMS-related syncope events in children is associated with school periods and long holiday periods. During school periods, being female is a risk factor for syncope, while situational syncope is a protective factor.

Guidelines for the diagnosis and treatment of neurally mediated syncope in children and adolescents (revised 2024)

BACKGROUND

Significant 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 effectively 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 classification 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. Specific 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.

Clinical features and response at head-up tilt test of patients with situational syncope

OBJECTIVE

The study compared clinical characteristics and response at head-up tilt test (HUTT) between situational (SS) and vasovagal syncope (VVS).

METHODS

Consecutive patients who underwent nitroglycerin-potentiated HUTT were retrospectively dichotomised into two groups: those with a history of SS and those with a history of VVS. The patients with SS were further subdivided into patients with SS alone and with SS and at least one episode of VVS.

RESULTS

1285 patients were enrolled: 246 (19.1%) had SS (SS alone in 121 and SS+VVS in 125). Patients with SS were older (48.8±20.0 vs 44.4±19.1, p=0.007) and more frequently male (57.3% vs 47.7%, p=0.001). At multivariable analysis, smoking habit (OR 2.28; p<0.0001), history of traumatic syncope (OR 2.29; p=0.0001) and ACE inhibitors/angiotensin II receptor blockers (OR 4.74; p<0.0001) were independently associated with SS. HUTT was positive in 175 (71.1%) patients with SS and in 737 (70.9%) patients with VVS (p=0.9). Patients with SS showed more mixed (42.3% vs 32.0%, p=0.002) and vasodepressor forms (10.6% vs 6.1%, p=0.01) and less cardioinhibitory responses compared with others (18.3% vs 32.8%, p<0.0001).

CONCLUSIONS

Compared with VVS, patients with SS have different clinical characteristics and a higher prevalence of hypotensive drugs leading to hypotensive susceptibility. The positivity rate of HUTT is high and similar to that of VVS, although patients with SS show a higher prevalence of hypotensive responses.

Syncope without prodromes is associated with excessive plasma release of adenosine at the time of syncope during head-up tilt table test

BACKGROUND

In syncopal patients without underlying structural disease, we sought to investigate the association of Adenosine Plasma Levels (ADP) with the clinical presentation of neurally mediated syncope (NMS) and the outcomes of Head-Up Tilt Table Test (HUTT) and Adenosine test (ADT).

METHODS

We studied 124 patients with different clinical types of NMS, i.e., Vasovagal (VVS, n=58), non-prodromes (NPS, n=18), or situational syncope (SS, n=48), using a standard protocol including HUTT and ADT. During HUTT, ADP was measured in the supine position, at table tilting and in syncope.

RESULTS

Baseline ADP did not differ among groups. ADP at syncope were higher in NPS (n=5) compared to VVS (n=20): 0.23 vs. 0.12 μΜ, p=0.03, and SS (n=22): 0.04 μΜ, p=0.02. In NPS, ADP increased from supine to syncope (n=5): 0.15 vs. 0.23 μΜ, p=0.04. In VVS, ADP increased only from supine to tilt position: 0.11 vs. 0.14 μΜ, p=0.02. In SS, ADP did not change during HUTT. In positive vasodepressor HUTT, ADP increased from supine to tilt position (p=0.002) and at syncope (p=0.01). In SS, 20.0% exhibited cardioinhibitory HUTT vs. 6.8% in other forms of syncope (p=0.04). In SS, 22.9% manifested positive ADT vs 6.6% in other types of syncope (p=0.012).

CONCLUSION

The subset of NPS patients with positive HUTT, show excessive ADP release at the time of syncope. This may explain the lack of prodromes in this form of syncope. Such observations contribute to the understanding of distinct profiles of clinical forms of syncope and may differentiate the management approach accordingly.