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Revista Española de Cardiología (English Edition) Revista Española de Cardiología (English Edition)
Rev Esp Cardiol. 2018;71:207 - Vol. 71 Num.03 DOI: 10.1016/j.rec.2017.10.021

Response to ECG, February 2018

Pablo Elpidio García-Granja a,b,, María Sandín Fuentes a,b, Emilio García-Morán a,b

a Instituto de Ciencias del Corazón (ICICOR), Hospital Clínico Universitario de Valladolid, Valladolid, Spain
b CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain

Refers to

Free articleECG, February 2018  Only available in Spanish
Pablo Elpidio García-Granja, María Sandín Fuentes, Emilio García-Morán
Rev Esp Cardiol. 2018;71:115
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This was a case of ventricular extrasystoles superimposed on sinus rhythm with P waves blocked by concealed and incomplete penetration of extrasystoles in the bundle of His1, 2 (correct answer, response 2). Figure shows the surface and bundle of His electrocardiograms (A, atrium; H, His; V, ventricle). The patient is in sinus rhythm and the P waves have a relatively constant cycle duration (924 ms) and typical and stable morphology (response 3 and 4, incorrect). Capture of the ventricular extrasystole by the bundle of His leads to suprahisian block of the following atrial pulse (incomplete penetration). The suprahisian block then enables atrioventricular node (AVN) recovery and improved suprahisian conduction in the following pulse (shortening of the A-H interval from 171 to 126 ms). There is no intrinsic defect in conduction, but rather a physiological response of the AVN to incomplete penetration of a ventricular extrasystole (response 1, incorrect).



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2. Langenford R. Concealed A-V conduction: the effect of blocked impulses on the formation and conduction of subsequent impulses. Am Heart J. 1974;35:542.

1885-5857/© 2018 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved