Incessant Focal Atrial Tachycardia Originating From the Right Inferior Pulmonary Vein With Extremely Short Cycle Length and Variable Exit Block

Figures

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  Figure 1. (A) The rhythm strip shows atrial ectopic beats and nonsustained atrial tachycardia mimicking atrial fibrillation. (B) Twelve‐lead ECG during a sinus rhythm and atrial tachycardia. P‐wave morphology on AT demonstrates positive deflection in Leads I, II, aVL, aVF, and V1–V6, and the PP interval was approximately 0.3 s. SR = sinus rhythm; AT = atrial tachycardia.

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  Figure 2. Intracardiac electrograms at the spontaneous initiation of AT with repetitive regular potentials (black down‐pointing triangle) in the RIPV. Nonsustained firing during the first sinus beat is not conducted to the adjacent LA. AT is then induced by the next rapid burst from the RIPV with a TCL of approximately 70 ms. SR = sinus rhythm; AT = atrial tachycardia; RIPV = right inferior pulmonary vein; LA = left atrium; TCL = tachycardia cycle length; CS = coronary sinus.

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  Figure 3. (A) Intracardiac electrograms demonstrate variable exit block during AT activation to the ablation catheter (ABL) site with 2:1 (arrow), then RIPV and CS with 4:1 conduction block (black diamond). ABL was located at the posterior aspect of the RIPV, and RF ablation was performed at this site, resulting in successful termination of AT. (B) Fluoroscopic view of the successful ablation site. RSPV = right superior pulmonary vein; RIPV = right inferior pulmonary vein; CS = coronary sinus; AP = anteroposterior; LAO = left anterior oblique.