An unusual type of long RP tachycardia: What is the mechanism?
An 81-year-old man underwent diagnostic electrophysiological study because of daily rapid palpitations. His 12-lead electrocardiogram and echocardiogram were normal. At baseline, he was in a nearly incessant tachycardia, which otherwise was easily inducible with atrial and ventricular stimulation (Figure 1, top). The response of tachycardia to ventricular premature depolarizations (VPDs) and entrainment from the ventricle are shown in Figure 1 (middle, bottom) and Figure 2, respectively. Based on the tracings, what is the mechanism of the tachycardia?
Source: Heart Rhythm - Category: Cardiology Authors: Reginald T. Ho Tags: Unknown of the Month Source Type: research