Distinguishing the Patients with Syncope and Those without it During Breath Holding Spell (BHS) Attacks According to the Assessment of QTc Dispersion in Electrocardiography (ECG).

Background: Breath holding spells (BHS) are common paroxysmal non-epileptic disorders. It occurs mostly among children 6 to18 months of age. Autonomic nervous system dysfunction is thought to be the primary abnormality in the pathophysiology of BHS. Maturation delay in myelination of the brainstem, Iron deficiency anemia, a genetic causative factor, low frustration tolerance could be the causes. On the other hand, these spells may rarely be an initial symptom of long QT syndromes or paroxysmal cardiac rhythm abnormalities in some patients. So QT syndrome and paroxysmal rhythm abnormalities must be considered in the differential diagnosis of these attacks. QT dispersion is found to be increased in children with long QT syndrome. The aim of this study was to find any difference between the patients with and without syncope during attacks of BHS according to QTc dispersion which is calculated from ECG. Materials and Method: The study group consisted of 66 children under 10 years of age (34 boys, 32 girls), 16 of which did not have syncopal attack with BHS and 50 were with syncope. QT interval which is from the beginning of Q wave till the end of T wave by millisecond, corrected QT interval (QTc),QT dispersion (by subtracting the shortest QT from the longest one in the same 12 lead ECG) and QTc dispersion (QTCd), peak to end of the T wave duration (TPe) and its dispersion (TPed) were measured. Results: QTcd was significantly increased in the patients with syncopal BHS, compared to nonsyncopal BHS patients (148.2±33.1 vs. 53.31±16.96 with p-value ≤ 0.0001). TPed was also significantly increased in the syncopal BHS, in comparison with non syncopal counterparts (47 ±20.3 vs., 23.75± 8.06, respectively; P-value≤ 0.0001). Conclusion: Significant Increase in QTcd and TPed was seen in the patients with syncopal BHS attacks, indicating that autonomic dysfunction is more prominent in this subgroup of patients.

کلیدواژه ها:

breath holding spell ، syncope ، QTc ، QTC dispersion