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Figure 2 Example of a Single Ventricular Extrastimulus Pre-Exciting a VT Resulting in Resetting

At the top are electrocardiographic (ECG) leads aVR and V₁ showing ventricular tachycardia (VT) with a cycle length of 520 ms. At the bottom is a reconstructed electrogram within the systolic portion of the circuit showing pre-excitation at 386 ms. The return cycle electrogram occurs 468 ms later, and the VT has been reset by 176 ms.