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Revista Española de Cardiología (English Edition) Revista Española de Cardiología (English Edition)
Rev Esp Cardiol. 2017;70:198 - Vol. 70 Num.03 DOI: 10.1016/j.rec.2016.11.013

Response to ECG, February 2017

Javier León Jiménez a,, Santiago Jesús Camacho Freire a, Raúl López Aguilar a

a Servicio de Cardiología, Complejo Hospital Juan Ramón Jiménez, Huelva, Spain

Refers to

ECG, February 2017
Javier León Jiménez, Santiago Jesús Camacho Freire, José Raúl López Aguilar
Rev Esp Cardiol. 2017;70:119
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See the proposed resolutions


The correct answer is number 4. This dual-chamber pacemaker is functioning normally. There are 2 leads, 1 for pacing the Bachmann interatrial bundle and the other for pacing the bundle of His. The resulting bipolar physiological Hisian pacing does not lead to any changes in QRS morphology (Figure 1).

Figure 1.

Given the particular features of pacing in this case, there is no loss of capture (answers 1 and 2) because all the spikes are still present in the QRS complex. Twiddler syndrome (answer 3) is ruled out by chest x-ray (Figure 2).

Figure 2.

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1885-5857/© 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved