Педиатрическая фармакология (Feb 2016)

Vagal Techniques for Terminating Paroxysmal Tachycardia in Children: Assessment of Clinical Electrophysiological Factors of Valsalva Test Effectiveness

  • T. K. Kruchina,
  • G. A. Novik,
  • D. F. Yegorov

DOI
https://doi.org/10.15690/pf.v12i6.1486
Journal volume & issue
Vol. 12, no. 6
pp. 639 – 644

Abstract

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Background: Vagal techniques constitute the first line of medical care for terminating paroxysmal supraventricular tachycardia in children and adults due to ease of application, relative safety and possibility of avoiding injection of antiarrhythmic drugs. Effectiveness of vagal techniques depends on the method of execution, as well as a range of clinical and electrophysiological factors, which require study and specification. Objective: Our aim was to study effectiveness of the modified Valsalva test for terminating paroxysmal tachycardia in children. Methods: Effectiveness of the Valsalva test for terminating paroxysmal tachycardia induced in the course of a transesophageal electrophysiological examination in children aged 7–18 years was studied retrospectively. Results: Data of 306 children (mean age — 13.1 ± 3.2 years) were analyzed; 130 of them (42.5%) suffered from paroxysmal AV nodal reentrant tachycardia (PAVNRT), 176 — from paroxysmal AV reentrant tachycardia involving an additional AV connection (PAVRT). Valsalva test was effective in 88 children (28.8%) — 44 children (33.8%) with PAVNRT and 44 children (25.1%) with PAVRT. In most cases, tachycardia was terminated by means of anterograde block: PAVRT — in 65.5% of the cases, PAVNRT — in 92.7% of the cases. Children with ineffective Valsalva test featured longer duration of the disorder (p = 0.035), higher rate of the initial sinus rhythm before a tachycardic paroxysm (p = 0.043) and higher rhythm rate during tachycardia (p = 0.019), as well as high level of AV node conduction (p = 0.038). Conclusion: Valsalva test terminates paroxysmal tachycardia in not more than 1/3 of children with paroxysmal AV reentrant tachycardia. Test effectiveness depends on duration of the disorder and electrophysiological characteristics of AV node conduction. Valsalva test is especially effective in the onset of tachycardic paroxysm and terminates it by means of anterograde AV node block in most cases.

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