Provocation of neurocardiogenic syncope during head-up tilt testing in children: comparison between isoproterenol and nitroglycerin

Clinical and Autonomic Profile, and Modified Calgary Score for Children and Adolescents with Presumed Vasovagal Syncope Submitted to the Tilt Test

BACKGROUND

In the pediatric population, syncope is mainly from vasovagal (VVS) origin. Its evaluation must be done by clinical methods, and the tilt test (TT) can contribute to the diagnosis.

OBJECTIVES

To analyze the clinical profile, Calgary and modified Calgary scores, response to TT and heart rate variability (HRV) of patients aged ≤ 18 years with presumed VVS. To compare the variables between patients with positive and negative responses to TT.

METHOD

Observational and prospective study, with 73 patients aged between 6 and 18 years, submitted to clinical evaluation and calculation of scores without previous knowledge of the TT. It was done at 70º under monitoring for HRV analysis. P-value < 0.05 was the statistical significance criterion.

RESULTS

Median age was 14.0 years; 52% of participants were female, 72 had Calgary ≥ -2 (mean 1.80), and 69 had modified Calgary ≥ -3 (mean 1.38). Prodromes were observed in 59 patients, recurrence in 50 and trauma in 19. The response to TT was positive in 54 participants (49 vasovagal, with 39 vasodepressor responses), with an increase in the low frequency (LF) component and a decrease in the high frequency (HF) component (p < 0,0001). In the supine position, LF was 33.6 in females and 47.4 in normalized units for males (p = 0.02). When applying the operating characteristic curve for positive TT, there was no statistical significance for HRV and scores.

CONCLUSION

Most children and adolescents with a presumed diagnosis of VVS presented a typical clinical scenario, with a Calgary score ≥ -2, and a predominant vasodepressor response to TT. Greater sympathetic activation was observed in the supine position in males. Calgary scores and sympathetic activation did not predict the response to TT.

Geçici Bilinç Kaybıyla Başvuran Çocuk Olguların Retrospektif Değerlendirilmesi

Amaç: Çalışmamızın amacı , geçici bilinç kaybı (GBK) yakınması ile başvuran çocuk olguların tanılarının aydınlatılması, anamnez, etiyoloji, özgeçmiş ve soygeçmiş, fizik muayene ve laboratuvar bulgularının, tedavilerinin retrospektif değerlendirilmesidir. Gereç ve Yöntemler: Çalışmaya Süleymen Demirel Üniversitesi Tıp Fakültesi Hastanesine GBK yakınmasıyla 1 Ağustos 2017-1 Şubat 2020 tarihleri arasında çocuk polikliniklerine başvuran hastalar dahil edildi, kaydedilen anamnezleri, fizik muayene bulguları detaylı olarak geriye dönük incelendi. Yapılan biyokimyasal laboratuvar incelemeleri, elektrokardiyografi (EKG), transtorasik ekokardiyografi (EKO), 24 saatlik ritm holter EKG, kraniyal manyetik rezonans (MR) görüntüleme, elektroensefalografi (EEG) retrospektif olarak tanıya ve tedaviye yönelik değerlendirildi. Bulgular: Hastaların 110’u (%68.8) kız, 50’si (%31.2) erkek idi. Hastaların ortalama yaşı 11.4 (±4.8) idi. Hastaların geçirdikleri ortalama GBK sayısı 1.6 (±1.2) idi. Çalışmamızdaki hastaların %33’ü tekrarlayan GBK atakları ile başvurmuştu. Çalışmamızda GBK tanısına yönelik yapılan ileri incelemelerde en sık neden vazovagal senkop (VVS) (51 hasta, %31.9), ikinci olarak epilepsi/FK/AFK (febril konvülzyon/afebril konvülzyon) (41 hasta, %25.6), üçüncü olarak psikojenik senkop (28 hasta, %17.5 ) olarak saptanmıştır. Diğer nedenler de sırasıyla durumsal, katılma nöbeti, OH (ortostatik hipotansiyon), migren/SVO (serebrovasküler olay), kardiyojenik, BPPV (benign paroksizmal pozisyonel vertigo) olarak bulunmuştur. Hastalara yapılan biyokimyasal tetkikler, EKG, EKO, 24 saatlik ritm holter EKG, EEG, kraniyal MR incelemeleri analiz edildi ve değerlendirildi. Sonuç: GBK yakınmasıyla başvuran her hastadan ayrıntılı anamnez alınmalı, tam sistemik muayene yapılmalı ve EKG çekilmelidir. Kan testleri, EEG, EKO, nörogörüntüleme, 24 saatlik ritm holter EKG değerlendirmeleri ön tanıya yönelik istenmelidir.

Neurally Mediated Syncope in Children and Adolescents: An Updated Narrative Review

Syncope presents a proportion of up to 25% among children and adolescents and accounts for 0.9% of emergency room visits. Its most frequent aetiology is neurally mediated syncope, which includes vasovagal syncope and orthostatic hypotension. Up to 70% of the paediatric population with reflex syncope is female. There are usually precipitating factors and prodromes. This mini-review will discuss the particularities of the clinical presentation, diagnosis, modified Calgary score, indications and accuracy of the head-up tilt test, classification, and pathophysiology in four sequential phases. Prognostic data and the non-pharmacological and pharmacological approaches will also be reviewed and differences regarding reflex syncope in adults will be discussed.

Twenty-four-hour urine NE level as a predictor of the therapeutic response to metoprolol in children with recurrent vasovagal syncope

BACKGROUND

Vasovagal syncope (VVS) is a heterogeneous disorder that creates challenges for treatment. Metoprolol is an important therapeutic option for children with VVS.

AIMS

The study examined the predictive value of 24-h urine norepinephrine (NE) levels in the assessment of the therapeutic efficacy of metoprolol for recurrent VVS in children.

METHODS

Thirty-eight children with recurrent VVS and 20 healthy children were enrolled in our study. Twenty-four-hour urine NE levels were measured by LC-MS-MS. VVS children were diagnosed by BHUTT and/or SNHUTT, and received metoprolol treatment for 3 months. Symptom scoring was utilized to evaluate the therapeutic effect. A ROC curve was used to investigate the predictive value of 24-h urine norepinephrine levels.

RESULTS

There exists significant correlation between 24-h urine NE levels and supine systolic and diastolic blood pressures. The 24-h urine NE levels of responders (40.75 ± 12.86 μg/24 h) were higher than those of nonresponders (21.48 ± 6.49 μg/24 h), and there was a significant difference between the two groups (P < 0.001). A ROC curve of the predictive value of 24 h urine NE levels revealed that the area under the curve was 0.926. A cutoff value for 24-h urine NE level of 34.84 μg/24 h produced both high sensitivity (70%) and specificity (100%) in predicting the efficacy of metoprolol therapy for VVS.

CONCLUSIONS

Patients with high 24-h urine NE levels have higher supine systolic and diastolic pressures and more effective responses to metoprolol. A 24-h urine norepinephrine level of > 34.84 μg/24 h was an indicator of the effectiveness of metoprolol therapy for VVS in children.

Usability of the head upright tilt test for differentiating between syncopal and seizure-like events in children

The common diagnosis of loss of consciousness and clonic movements in children is seizure or epilepsy, but in a number of patients these symptoms could also be due to syncope. Over interpreted electroencephalography is misleading in a number of patients; therefore, in addition to a detailed and thorough history, a reliable test is needed to differentiate between these conditions. The aim of the study was to evaluate the utility of the head upright tilt test to differentiate between seizure-like events and syncope in children. A chart review descriptive study was conducted in a tertiary medical center in Ahvaz, Iran. We selected sixteen children (nine boys and seven girls) with convulsions of any type who were first diagnosed as epileptic based on the event description by their parents or caregivers to undergo the head upright tilt test. The main findings were the reproduction of previously presyncopal or syncopal symptoms in the tilted position. Fourteen children showed positive results after conducting the head upright tilt test, and their heart rates were significantly decreased compared to baseline at the onset of the syncopal or presyncopal manifestations. Systolic and diastolic blood pressures were significantly reduced in patients with positive results. In three children who initially had negative head upright tilt tests, intravenous isoproterenol was administered, and all three showed presyncopal and syncopal symptoms. The results indicate that the head upright tilt test could differentiate presyncopal and syncopal events in children who present with seizure-like movements but their history has clues for conclusive syncope.

Depressive symptoms and neurocardiogenic syncope in children: a 2-year prospective study

OBJECTIVE

To evaluate prospectively the relationship between neurocardiogenic syncope (NCS) and depressive symptoms in pediatric patients.

METHODS

Forty-five patients (aged 12.3 ± 2.9 years) with NCS (diagnosed as ≥ 1 syncopal episodes with typical symptoms, reproduced by tilt-table testing, in the absence of structural or primary electrical heart disease) were compared with 45 age- and gender-matched control subjects. Assessment was performed at baseline and 2 years thereafter. Depressive symptoms and self-perception profile of participants were evaluated, along with their parents' psychological distress, defensive profile and hostility. Family cohesion and adaptability, as well as the opinion of parents and teachers on children's strengths and difficulties, were also examined.

RESULTS

At baseline, patients showed more (P = .008) depressive symptoms than controls, correlating with the number of syncopal episodes, impaired relationship with parents and poor family cohesion. A conservative management strategy of NCS was adopted and psychological counseling was offered, focusing on patients with clinically significant depressive symptoms and their families. During follow-up, depressive symptoms decreased in patients (P < .001), but remained stable in controls. Child-parent relationship, family cohesion and family adaptability improved at follow-up in patients. No recurrent syncope was noted during follow-up and this along with improvement in child-parent relationship were associated with depressive symptoms improvement.

CONCLUSIONS

Depressive symptomatology is common in pediatric patients with NCS. Our findings call for additional investigation in larger controlled clinical interventional studies that will enhance understanding of the possible pathophysiological association between depressive symptomatology and NCS in pediatric populations.

Application of head-up tilt table testing in children

BACKGROUND/PURPOSE

We investigated the application of head-up tilt table testing (HUT) and management of neurocardiogenic syncope (NCS) in children, as pediatric studies are limited.

METHODS

Seventy-nine patients (ages 6-18 years) underwent HUT for evaluation of syncope. Patient triggers and premonitory symptoms allowed the clinical diagnosis of NCS or non-NCS. Results were divided into four hemodynamic types (1, 2A, 2B, and 3) according to patient response to HUT.

RESULTS

NCS occurred in 65 patients and non-NCS in 14 patients. Isoproterenol infusion significantly increased the sensitivity of the test (from 28% to 45%) and was associated with a slight decrease in the specificity (from 93% to 86%). Subjects in the type 1 group accounted for the majority of responses to the test (69%). There were no complications associated with the test. At follow-up (16.6 ± 9.3 months), the overall recurrence rate was 30.8% but NCS was less severe in most patients. The recurrence rate was similar for patients with a positive or negative HUT and for both pharmacologically and non-pharmacologically treated patients.

CONCLUSION

HUT can be safely performed with a high specificity in children, with the sensitivity of HUT improved by isoproterenol. Therefore, a positive response to treatment is reassuring to the physician and family. NCS is generally a self-limited condition despite a high recurrence rate.

Head-up tilt table testing in syncope: safety and efficiency of isosorbide versus isoproterenol in pediatric population

BACKGROUND

The aim of this study was to compare the diagnostic value and safety of sublingual isosorbid dinitrate (ISDN) with intravenous isoproterenol (ISOP) during head-up tilt table testing (HUTT) in pediatric patients with suspected neurocardiogenic syncope.

METHODS

One hundred thirty-six consecutive pediatric patients complaining of presyncope or syncope were submitted to HUTT for the first time. Those who did not develop syncope or presyncope during passive HUTT for 20 minutes underwent repeated HUTT with either 1.25 to 2.5 mg sublingual ISDN or intravenous ISOP (1-3 mug/min) for 20 minutes. There were 54 boys and 82 girls, aged 10 to 18 years with an average of 15.5 +/- 2.4 years and a median of 16 years. Among the patients with cardioinhibition or mixed responses, the severity of the bradyarrhythmia was scored 1 to 3 (restoration of effective rhythm within 10 seconds, 10-20 seconds, and >20 seconds while back to supine position, respectively).

RESULTS

During the passive period, 24 (17.6%) of 136 patients had a positive response to HUTT. Syncope was observed in another 44 patients during either ISDN or ISOP period (14/58 [24.1%] and 30/54 [55.5%] with ISDN vs ISOP, respectively, P < .05). The time to symptoms was shorter with both ISDN and ISOP compared with passive period (6.5 +/- 2.9, 6.3 +/- 5.9, and 10.3 +/- 4.4, minutes, respectively, P < .05). The severity score for cardioinhibition response was significantly higher with ISDN compared with the passive period and ISOP (2 +/- 0.8, 1.25 +/- 0.45, and 1.26 +/- 0.45, respectively, P < .01).

CONCLUSIONS

Sublingual ISDN is less sensitive and less safe compared to intravenous ISOP in assessing pediatric age patients with suspected neurocardiogenic syncope and with a negative result in tilt test without provocation. The simplicity of ISDN use should be weighed against the risk of longer symptoms with ISDN.