Humans ; Pediatrics ; methods ; Syncope ; diagnosis ; etiology ; therapy

Electrocardiography ; Female ; Humans ; Syncope/etiology* ; Torsades de Pointes/etiology*

Objective: To analyze the clinical characteristics and risk factors of malignant vasovagal syncope (VVS) in children. Methods: This was a case-control study. The data of 368 VVS patients who were treated in the Department of Cardiology, Children's Hospital, Capital Institute of Pediatrics from June 2017 to December 2021 was collected and analyzed. They were divided into malignant VVS group and non-malignant VVS group according to the presence of sinus arrest, and then their demographic characteristics were compared. The children with malignant VVS and complete clinical information were recruited into the case group and were matched by age and sex (1∶4 ratio) with non-malignant VVS patients during the same period.Their clinical characteristics and lab tests were compared. Independent sample t test, Mann Whitney U or χ² test was used for comparison between groups.Logistic regression was used to analyze the risk factors for malignant VVS in children. Results: Eleven malignant VVS and 342 non-malignant VVS met the inclusion and exclusion critera. Eleven malignant VVS and 44 non-malignant children were recruited in the case-control study. Ten patients of the 11 malignant VVS had a cardiac arrest occurring at 35 (28, 35) minutes of the head-up tilt test, and the duration of sinus arrest was (9±5) s. One patient had syncope occurring while waiting for drawing blood, and the duration of sinus arrest was 3.4 s. The children with malignant vasovagal syncope were younger than non-malignant VVS patients (9 (7, 10) vs. 12 (10, 14) years old, P<0.05), and had higher mean corpuscular hemoglobin concentration (MCHC) and standard deviation of the mean cardiac cycle over 5-minute period within 24 hours ((347±9) vs. (340±8) g/L, (124±9) vs. (113±28) ms, both P<0.05). Logistic regression analysis showed that MCHC was an independent risk factor for malignant VVS in pediatric patients (OR=1.13, 95%CI 1.02-1.26, P=0.024). Conclusions: The onset age of malignant VVS was younger, with no other special clinical manifestations. MCHC was an independent risk factor for malignant VVS.
Humans ; Child ; Adolescent ; Syncope, Vasovagal/etiology* ; Case-Control Studies ; Syncope ; Risk Factors

Child ; China ; Congresses as Topic ; Humans ; Pediatrics ; Syncope ; diagnosis ; etiology ; therapy

Acupuncture Therapy ; Adult ; Dysmenorrhea ; complications ; Female ; Humans ; Syncope ; etiology ; therapy

Electrocardiography ; Female ; Humans ; Middle Aged ; Pulmonary Embolism ; complications ; Recurrence ; Seizures ; etiology ; Syncope ; etiology

Swallowing is a rare cause of neurally mediated syncope. The mechanism of swallow syncope that contributes to hypotension, bradycardia, or to both is complex. A 59-year-old man had experienced a recurrent loss of consciousness during swallowing of carbonated beverages or sticky foods. Another 59-year-old man had complained of intermittent syncope just after eating foods. These two patients had no significant structural or functional abnormalities in the esophagus or heart. Both cases showed bradycardia when the lower esophagus was stretched by balloon inflation. The activation of mechanoreceptors in the lower esophagus can be regarded as an initiating factor of these cardioinhibitions. The patients were treated with permanent pacemaker implantation and instructed to change eating habits, respectively.
Bradycardia/etiology ; Deglutition/*physiology ; Esophagus/*innervation ; Humans ; Male ; Mechanoreceptors/*physiology ; Middle Aged ; Syncope/*etiology

A 17-year-old high school student presented with a history of habitual faintings. On 24-hour Holter monitoring, cardiac asystoles were recorded, the longest lasting approximately 7 or 8 seconds during venipuncture procedures. The asystole associated with venipuncture demonstrated the cardioinhibitory effects of vasovagal reaction with blood-injury phobia. He also had a positive response during head-up tilt test showing hypotension and relative bradycardia after intravenous isoproterenol injection. After administration of oral beta blocker, he did not show further or recurrent cardiac asystole during blood injury procedure on electrocardiographic examination. Venipuncture is the most common invasive medical procedure performed in hospital settings. While venipuncture is considered to be reasonably safe, serious complication may occur even when only a small volume of blood is withdrawn. Therefore, medical personnel should be prepared to provide appropriate care.
Adolescence ; Case Report ; Heart Arrest/etiology* ; Human ; Male ; Phlebotomy/psychology* ; Recurrence ; Syncope/etiology ; Vagus Nerve/physiology*

OBJECTIVESyncope is a common problem in children and adolescents. Such an event may have multiple possible causes, ranging from benign conditions to life-threatening diseases. Syncope is a major challenge for the practicing physicians. It is very important to know the etiologic and clinical characteristics of syncope in children. This study aimed to improve diagnostic efficacy of syncope in children by analyzing the etiology and clinical characteristics of syncope.

METHODSThe investigators retrospectively analyzed the causes of syncope and diagnostic workup of 154 consecutive children seen in Department of Pediatrics, Peking University First Hospital because of a syncopal event.

RESULTSAutonomic-mediated reflex syncope (AMS) was the most common cause of syncope (65.6%), whereas cardiac disorders were found in 10 cases (6.5%) comprising the second cause of syncope in children. Other causes included psychologic problems and neurological and metabolic disorders. Although many causes were studied, 25 cases (16.2%) were found to have uncertain etiologies yet. The children with AMS were commonly seen in pubertal girls, and they had clear inducement of syncope and prodromes. The children with cardiac syncope often had history of cardiac diseases, and they were often younger than those with AMS. Lack of prodromes of syncope, exercise-related syncope, syncope spells seen in any body position, frequent syncope spells and sudden death in family were clues of cardiac syncope. Neurological disorders should be considered if there are any of the followings: syncope with seizure activity, syncope spells seen in any position, and a postictal phase of disorientation or neurologic abnormal signs. A metabolic cause was entertained when the child had a history of metabolic diseases, prolonged anger, or violent vomiting and diarrhea. Children with psychiatric disorders were adolescent girls with prolonged syncope spells, and had more frequent syncopal episodes. Most children with syncope were evaluated by many of diagnostic tests, but most of those tests were not goal-directed approach. Since persons with cardiac syncope were at increased risk for death from any cause, electrocardiography was recommended in almost all children with syncope. Neurologic testing including electroencephalography, computed tomography, etc. were rarely helpful unless neurologic signs and symptoms are present. Holter electrocardiography and echocardiography were most useful in children with suspected cardiac syncope. There was little benefit of screening cardiac enzyme in children with syncope. Routine blood tests (blood electrolytes and blood glucose, etc) rarely yield diagnostically useful information unless the children had the history of metabolic diseases. Head-up tilt testing was most useful in children with recurrent syncope in whom heart disease was not suspected. The children with frequent syncope, long lasting syncopal episode and clear psychiatric inducement of syncope should be evaluated by psychiatric testing.

CONCLUSIONSyncope in children may result from a wide variety of causes, and clinicians often use a wide range of investigation to try to achieve a diagnosis. But most of investigations have low diagnostic yield. Thorough history taking, physical examination and electrocardiography are the core of the syncope workup.

Adolescent ; Child ; Child, Preschool ; Electrocardiography ; Female ; Humans ; Male ; Retrospective Studies ; Syncope ; diagnosis ; etiology

OBJECTIVETo investigate the common causes of unexplained syncope in children.

METHODSA total of 434 children with unexplained syncope who were aged from 3.0 to 17.9 years (192 males and 242 females) and who saw the doctor between January 2006 and October 2011. were examined in order to explore the detailed histories and causes of syncope and to analyze variance in causes among different ages, genders, syncope frequencies and head-up tilt test (HUTT) results.

RESULTS(1) The causes of occasional syncope included persistent standing (30%), movement (13%), change in body position(9%), sitting(7%), and playing(6%). Persistent standing was more common as a cause in females than in males (P<0.01). Micturition syncope was mainly seen in males. Sultry weather was the main cause of syncope in females. Change in body position was a more common cause in the ≥12 years group than in the <12 years group (P<0.05), while other causes showed no significant differences among different age groups. Change in body position was a more common cause of syncope in children with negative HUTT results than in those with positive HUTT results (P<0.05). (2) All causes of occasional syncope can induce repeated syncope, and most repeated syncope (56%) had the same cause.

CONCLUSIONSThe common causes of unexplained syncope include persistent standing, movement and changes of body position in children. Avoiding these causes is helpful for prevention of childhood syncope.

Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Male ; Posture ; Syncope ; etiology ; Tilt-Table Test ; Weather