ISSN: 1885-5857
Vol. 73. Num. 6.
Pages 502 (June 2020)

Ecg contest
Response to ECG, May 2020

Respuesta al ECG de mayo de 2020

Ez Alddin Rajjoub Al-MahdiÁlvaro Lorente RosVanesa Cristina Lozano Granero
Rev Esp Cardiol. 2020;73:40810.1016/j.rec.2019.11.009
Ez Alddin Rajjoub Al-Mahdi, Álvaro Lorente Ros, Vanesa Cristina Lozano Granero

Options

A regular narrow QRS tachycardia at 176 bpm is present with RP shorter than PR (figure 1). The rapid remission of the tachycardia with carotid sinus massage points to a paroxysmal supraventricular tachycardia (option 2 incorrect). The P wave at the end of the tachycardia also rules out atrial tachycardia (option 1 incorrect). The third, fourth, and fifth beats observed after the maneuver, with broad QRS and short PR, are consistent with pre-excited beats, and this points to diagnosis of orthodromic tachycardia (option 4 correct, option 3 incorrect) via a hidden accessory pathway, that is, a pathway that can support anterograde conduction although not visible in the baseline ECG. This type of pathway is more usually left-sided (given the greater distance from the sinus node) and may become apparent with maneuvers that cause atrioventricular node block. Electrophysiological study confirmed the presence of a posterolateral accessory pathway, which was successfully ablated.

Figure 1
(0.54MB).
Are you a healthcare professional authorized to prescribe or dispense medications?