Syncope in the pediatric patient

Syncope in a 14yo female with ventricular tachycardia; an atypical etiology

Wide complex tachycardias are rare in the pediatric population and may be due to ventricular tachycardia, aberrant conduction or antidromic tachycardia each with multiple underlying etiologies. We present a 14 yo female in extremis with syncope at rest witnessed by her mother, found in ventricular tachycardia by EMS who challenged with IVF hydration and amiodarone. Consecutive adequate fluid challenges and antiarrhythmics in the emergency department failed requiring synchronized cardioversion for stabilization. Subsequent viral panels, imaging, genetic testing and cardiac biopsy confirmed a diagnosis of arrhythmogenic right (and left) ventricular dysplasia.

Lack of Utility in Performing Blood Glucose Measurement and Electrocardiogram in the Outpatient Evaluation of Benign Pediatric Syncope

We aimed to determine the frequency of blood glucose and electrocardiogram (EKG) abnormalities in previously healthy children who present to an emergency department (ED) with a diagnosis of benign syncope. Chart review of consecutive children aged 5 to 18 years presenting to the pediatric ED from 2004 to 2014 with a discharge diagnosis of benign syncope was done. Of 969 patients, hypoglycemia (serum glucose <60 mg/dL) was present in only 3 cases (0.3%). Of 754 patients with EKG performed, only 4 cases (0.6%) was an abnormality requiring further cardiac evaluation identified; cardiac echocardiogram was performed in 3 of these 4 patients, which revealed no cardiac pathology. Financial analysis for performing blood glucose measurement and EKG on these patients amounted to total health care cost of $222 526. We concluded that previously healthy children with syncope rarely have hypoglycemia or underlying cardiac abnormality. The routine performance of tests can incur significant health care expenditure.

Recovery position significantly associated with a reduced admission rate of children with loss of consciousness

BACKGROUND

Loss of consciousness (LOC) is often seen in children. The response of caregivers to a child with LOC has been poorly investigated. Potential caregivers (parents, teachers) seem to have a poor knowledge of the recovery position (RP)-that is, the position into which an unconscious child should be placed in order to protect the airway.

OBJECTIVES

To report the management and diagnoses of LOC in childhood, and to evaluate variables associated with an increased hospital admission rate.

METHODS

We conducted a prospective cohort study of consecutive children aged between 0 and 18 years diagnosed with LOC at 11 paediatric emergency departments (PEDs) of 6 European countries. The enrolment period was 3 months. Data were obtained from parental interviews, PED reports and clinical examination.

RESULTS

553 children were enrolled. The most frequent final diagnoses causing LOC were seizures (n=278, 50.3%), and vasovagal syncope (n=124, 22.4%). Caregivers put the child in the RP in 145 cases (26.2%). The RP was independently associated with a significant decrease in the admission rate (aOR=0.28; 95% CI 0.17 to 0.48; p<0.0001).

CONCLUSIONS

Our study demonstrates for the first time that the RP may reduce the admission rate of infants with LOC. Caregivers often perform inadequate manoeuvres when a child becomes unconscious. Campaigns aiming at increasing knowledge of the RP should be promoted.

The Evaluation and Management of Pediatric Syncope

Syncope is a common problem in children and adolescents. It is typically caused by benign neurally mediated hypotension, but other, more concerning, etiologies of syncope must be considered. In most instances, the underlying cause of syncope in the pediatric patient can be determined by obtaining a thorough history and physical examination. Attention to the cardiac, neurological, and psychological history and examination can rule out more rare causes of loss of consciousness. Most individuals with neurally mediated hypotension can be treated with lifestyle measures including aggressive hydration, dietary salt, and an exercise program. In instances where lifestyle modification fails, medications may offer symptomatic improvement.

Evaluation rhythm problems in unexplained syncope etiology with implantable loop recorder

BACKGROUND

Syncope is a frequent complaint in children and adolescents and may be a significant sign of serious pathology. Although patient history, family history, and physical examination are sufficient to reach a diagnosis in most cases of syncope, the cause of syncope still cannot be determined after initial investigation in one-third to half of all patients. The aim of this study was to evaluate the diagnostic yield of implantable loop recorder (ILR) in children with unexplained syncope.

METHODS

A retrospective review was carried out of clinical data, indications, findings, and a final management strategy in patients who underwent ILR implantation.

RESULTS

A total of 12 patients with a mean age of 9.4 ± 4.5 years underwent ILR (Reveal Plus; Medtronic) implantation. ILR implantation indication was syncope in all of the patients. Family history, routine cardiac assessment, including resting 12-lead electrocardiogram, transthoracic echocardiography, 24 h Holter recording, and event recorder findings, were normal with the exception of one patient with (previously corrected) tetralogy of Fallot. After an average of 20 months (range, 1-36 months), six patients developed symptoms. ILR memory showed torsades de pointes-ventricular fibrillation (n = 3), catecholaminergic polymorphic ventricular tachycardia (n = 1), asystole and ventricular tachycardia (n = 1), and normal sinus rhythm (n = 1). At the time of writing six patients were still in follow up with no symptoms after an average of 25.2 months.

CONCLUSION

Implantable loop recorder plays an important role in the diagnosis of life-threatening arrhythmias in which syncope is otherwise unexplained. ILR implantation should be remembered in children whose symptoms are strongly correlated with rhythm disturbances.

Syncope in children and adolescents: Evaluation and treatment

Syncope in children is most often neurally mediated and usually has a natural history of spontaneous resolution or improvement. Syncope is defined as the temporary loss of consciousness resulting from a reversible disturbance of cerebral function. It is characterized by a loss of consciousness due to a lack of cerebral blood flow, rapid or sudden onset, falling of the patient, if not supported, and transiency of the attack. In children, it is most often benign, but may sometimes herald a more serious, potentially life-threatening cause. The main purpose of the present paper is to propose an evaluation scheme that will allow the physician involved in the care of children to differentiate the life-threatening causes of syncope with potential for injury or sudden death from the common, more benign neurally mediated syncope. Secondarily, the present article facilitates the identification of the patient with neurally mediated syncope who may benefit from medical therapy and distinguishes syncope from the more frequent noncardiac 'spells' of childhood.

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

OBJECTIVE

Although nitroglycerin- and isoproterenol-augmented tilt tests are of equal value in the diagnosis of neurocardiogenic syncope in adults, no data exist in children. We compared the sensitivity and specificity of the 2 tests in a pediatric population.

PATIENTS AND METHODS

We studied 85 patients (33 boys; mean age: 11.6 +/- 2.9 years). Of them, 56 had a diagnostic history of neurocardiogenic syncope, whereas 29 served as controls. After a negative passive phase, they were randomly assigned to either intravenous isoproterenol or sublingual nitroglycerin, and tilt was continued for 20 minutes.

RESULTS

Sensitivity was 0.78 for the isoproterenol test and 0.79 for the nitroglycerin test, but specificity was significantly higher for isoproterenol test compared with nitroglycerin test. In patients with a positive test, the duration of the recovery period was significantly longer after nitroglycerin (8.4 +/- 2.7 minutes) than after isoproterenol (5.1 +/- 1.6 minutes).

CONCLUSIONS

Nitroglycerin- and isoproterenol-augmented tilt tests are associated with equal sensitivity in the diagnosis of neurocardiogenic syncope in children and adolescents. However, nitroglycerin results in more false-positive tests and produces more prolonged vasovagal symptoms. Our data do not support the routine use of nitroglycerin in the evaluation of syncope in this age group.

Use of the implantable loop recorder in children and adolescents

INTRODUCTION

Recurrent but infrequent syncopes represent a diagnostic challenge, since they frequently remain unexplained despite extensive investigations. This applies specifically for patients who carry an increased risk of potentially lifethreatening arrhythmias, either due to congenital cardiac disease or primary electrical disorders. Implantable loop recorders permit long-term electrocardiographic monitoring. Experience with these devices is still limited in children.

PATIENTS AND METHODS

Between January 1999 and August 2005, 12 patients underwent implantation of a loop recorder in our tertiary referral centre. The mean age was 10.9 years, with a range from 2 to 17 years. Of the patients, 6 had structural disease, 3 had primary electrical abnormalities, and 3 had no cardiovascular disease.

RESULTS

Resyncope occured in 9 of the 12 patients. Arrhythmic origin of the syncope was diagnosed in 4 of these patients. The events recorded were ventricular fibrillation in 2, intermittent asystole in 1, and pacemaker-syndrome in the other patient. Malignant arrhythmia was ruled out in the remaining 5 patients. There were no complications related to implantation of the loop recorder, and the mean duration until explantation was 8.3 months.

CONCLUSIONS

Based on our experience, we suggest that implantation of a loop recorder represents an additional tool for a selected group of children. Due to its invasive nature, it should be restricted to patients at high risk, or those in which there is substantial clinical suspicion of the likelihood of serious arrhythmias when conventional testing has been inconclusive. In this cohort, implantation of the loop recorder either helps to establish the correct diagnosis, or to exclude an arrhythmic event, thus avoiding unnecessary escalation of therapy and providing reassurance for the family.

Understanding and Managing Neurally Mediated Syncope in the Adolescent

Syncope and near-syncopal symptoms are common events in the adolescent population. Syncope is defined as the transient loss of postural tone and consciousness with spontaneous recovery. Although most syncopal events are benign, they can generate extreme anxiety in the adolescent and his or her family. The reoccurrence of these events can have a negative impact on an adolescent’s participation in daily activities. Understanding the process of assessment, diagnosis, and management of these teens can enable the school nurse to augment initial assessment and to support the prescribed treatment plan. This knowledge then can be used to help allay the adolescent’s anxiety and to support efforts at self-management. This article explores current literature in regards to etiology, diagnosis, and medical treatment, and advocates a self-management protocol for neurally mediated syncope in the adolescent population with support of that plan by the school nurse.

Abnormality of the Left Ventricular Sympathetic Nervous Function Assessed by I-123 Metaiodobenzylguanidine Imaging in Pediatric Patients with Neurocardiogenic Syncope

The purpose of this study was to assess the left ventricular sympathetic nervous system function in the patients with neurocardiogenic syncope (NCS) using I-123 metaiodobenzylguanidine (MIBG) imaging of the heart, and to compare the plasma noradrenaline (NA) and MIBG results of tilt positive and tilt negative patients following a head-up tilt test (HUT). The study included 30 patients. Their physical and laboratory examinations did not show a pathology that may be the cause of their syncope. HUT test was positive in 13 patients and negative in 17 patients. Plasma NA concentrations were higher in the HUT positive than the HUT negative group at the beginning and at the 10th minute of the test. Specific I-123 MIBG uptake assessed as the cardiac to mediastinal activity ratio in the delayed image was significantly higher in HUT positive group. The higher levels of MIBG uptake and plasma NA observed in HUT positive patients may reflect the greater capacity of NA storage in cardiac adrenergic neuronal tissue in patients with NCS. The results of this study support the critical role of autonomic nervous system in the pathophysiology of NCS and the excessive sympathetic nervous stimulation as the trigger of paradox reflex.

Use of an implantable loop recorder in the evaluation of children with congenital heart disease

BACKGROUND

A recently developed implantable loop recorder (ILR) has been used in adult patients whose syncope remains unexplained in spite of extensive investigations. Syncope in the patient with congenital heart disease presents a diagnostic challenge. We applied this technology to a cohort of pediatric patients.

METHODS

We reviewed our experience with an ILR in patients with congenital heart disease with syncope or palpitations after conventional investigations failed to identify a cause for the symptoms.

RESULTS

ILRs were implanted in 4 patients with congenital heart disease at 2 centers for investigation of syncope (n = 2), near-syncope (n = 1), and palpitations (n = 1). Implantations were performed at a mean age of 5.9 +/- 0.9 years (4.2 to 7.6 years) and a mean weight of 26.7 +/- 6.6 kg (15.7 to 42.5 kg) with patients under general anesthesia, with no complications. All patients experienced typical symptoms and activated the device appropriately at a median of 86 days (46 to 102) after implantation. Each patient had good-quality data that allowed interpretation of the rhythm. In 2 of 4 cases, a likely cause for the symptoms was identified, with exclusion of more malignant arrhythmic diagnoses in all patients. Escalation of therapy was avoidable in all patients on the basis of the data recorded by the ILR.

CONCLUSIONS

Recently developed loop recorder technology can be implanted in the young child without difficulty. The ILR proved to be very useful for excluding malignant arrhythmias as a cause of symptoms in these patients at high risk.