Clinical Use of Electrocardiography (ECG) in Children with Breath-Holding Spells

Breath holding spell (BHS) is one of the most common benign non-epileptic paroxysmal attacks in children triggered by a provocative action such as emotional distress and partial damage, and continues with breath-holding, cyanosis and syncope. They vary in how often they occur and how severe they are, however, decrease in frequency is obvious as the autonomic nervous system develops. Although these spells are benign, they can be terrifying to observers. Given their similarity to epileptic seizures, it is initially vital to differentiate these spells from epileptic seizures so that the child is not inappropriately treated with antiepileptic medications. Approximately 20–30 % of affected childrenchr('39')s parents is reported to have a history of the condition. A disorder in central autonomic regulation probably transmitted by autosomal dominant pattern of inheritance with incomplete penetrance is recognized to be the major cause. This study aimed to compare the electrocardiographic components and the demographic data of children with BHS and healthy children.

In this prospective and cross-sectional study, the population consisted of 60 children with BHS were selected as case group and 60 healthy children as controls who were the same in terms of age and sex. ECG was taken from all children, along with a history of previous spells and demographic information, by a researcher-made questionnaire at Amirkabir Hospital. As well as, a thorough clinical examination was conducted with special emphasis on the patient’s personal history, including age and gender, complaint (i.e., type of BHS, its duration and the provoking factors), family history of similar conditions and consanguinity, and developmental history. A “spell” or “episode” was defined as the stoppage of child’s breathing during expiration after a deep inspiration while crying. The spells were classified into two types of cyanotic and pallid spells. The study received ethical approval from the Research Ethics Committee of Arak University of Medical Sciences (IR.ARAKMU.REC.1396.191) for experiments involving humans. Finally, the results were analyzed using SPSS V24 software.

Echocardiography was normal in all children (n = 120) and did not show any abnormality. During the period of study (one year), 60 children were diagnosed with breath holding spells by clinical evaluation in Amirkabir Hospital located in Arak. The mean age was 25.75 ± 12.68 months for patients and 24.23 ± 13.36 for controls with an age range from 6 months to 5.5 years. The studied population consisted of 69 females and 51 males with no significant difference in their mean age (p <0.05). Among 60 children with BHS in the current study, 68.33% had cyanotic, 11.67% had pallid and 20% had mixed BHS. Anemia was also significant between the two groups. By calculating the mean values of P wave, PR segment, T wave, P and QRS amplitude, there was no significant difference between two groups of children with BHS and healthy children, while there was a significant difference between them in other ECG parameters. There was no significant difference for T wave among affected children and healthy children. In several studies, T wave peak and T end interval on the surface of ECG is found to be a useful marker for predicting the risk of developing life-threatening arrhythmias. T wave was measured in the current study in children with BHSs and healthy children and no significant difference was observed between these two groups. P-wave amplitude was then analyzed and no significant difference was observed between patients with 101.3 ± 10.8 mv and controls with 100.0 ± 00.0 mv. Additionally, there was statistically significant difference in QTcd between children with BHS (29.60 ± 19.85 ms) and controls (39.28 ± 4.1 ms). The difference in T interval was statistically significant between patients and control with values of 60.0 ± 26.5 ms and 40.0 ± 00.0 ms, respectively (P<0.01). According to our exclusion criteria, cases with persistent prolonged QT syndrome (LQTS) were not included in this study as prolonged QT syndrome associated with syncope is a serious condition needing interference up to pacemaker implantation.

According to the results of this study, familial history and anemia can have a positive effect on children with BHS. As BHSs are similar to some hazardous conditions such as long QT syndrome, evaluating electrocardiographic parameters is required in addition to clinical examinations and demographic information in children with BHS. And given that no research has been conducted on children with BHS in their adulthood, it is recommended to check the risk of cardiovascular diseases in these individuals in adulthood so that if such complications are observed, more attention should be paid to BHS treatment.