论文信息 - Unusual response to a ventricular extrastimulus during a narrow QRS tachycardia: What is the mechanism?

Unusual response to a ventricular extrastimulus during a narrow QRS tachycardia: What is the mechanism?

F IGURE 1 (A) Ventricular extrastimulus (St.) from the right ventricular apex (RVA) during the tachycardia. Abbreviations: A, atrium; CS, coronary sinus; H, His; HBE, His bundle electrogram; HRA, high right atrium tachycardia with the earliest atrial activation site of coronary sinus ostium (CSos). During the tachycardia, atrio-His andHis-atrio intervals were 138 and 180 ms, respectively. A single ventricular extrastimulus applied from the right ventricular apex (RVA) during the tachycardia is shown in Figure 1. This finding appeared with reproducibility. What is themechanism of this tachycardia?

[1] M. Shoda,et al. Novel Diagnostic Observations of Nodoventricular/Nodofascicular Pathway-Related Orthodromic Reciprocating Tachycardia Differentiating From Atrioventricular Nodal Re-Entrant Tachycardia. , 2020, JACC. Clinical electrophysiology.

[2] R. Ho,et al. The Various Manifestations of Concealed Nodo-Fascicular/Nodo-Ventricular Bypass Tracts. , 2020, Heart rhythm.

[3] W. Shimizu,et al. Analyses of the Mode of Termination During Diagnostic Ventricular Pacing to Differentiate the Mechanisms of Supraventricular Tachycardias. , 2017, JACC. Clinical electrophysiology.