A case of successful radiofrequency catheter ablation for atrial tachycardia originating from the inferior vena cava using high-resolution mapping

Fig. 1. A 12-lead surface electrocardiogram A. at rest, B. during supraventricular tachycardia, and C. during ectopic atrial rhythm. Black-color vertical lines in both limb and precordial leads are obtained just before the onset of the P wave. BPM, beats per minute.

Fig. 2. Intracardiac recordings during SVT induction via premature atrial contraction. Two different types of tachycardia with A. short cycle length of 450 ms, and with B. long cycle length of 650–700 ms, were induced. A shorter cycle length of 655 ms (asterisk), compared with the following three consecutive beats, is due to the fusion of SVT and premature atrial contraction. Note the earliest atrial activation was consistently observed from the electrodes positioned at the ostium of the coronary sinus (black arrowhead). C. Intracardiac recordings (left) at rest, and (right) during spontaneous SVT induction. Once the electrogram property from the electrodes at the ostium of the coronary sinus (CSp) changed from that of sinus rhythm (dagger), a gradual shortening of atrial cycle length (700 ms–690 ms) and D. further shortening of the atrial cycle length (675 ms) consistently surpassed that of sinus rhythm, which consequently provoked the negative P wave morphology at inferior limb lead (aVF). I/aVF, surface ECG leads; CSp/CSm/CSd, proximal, mid, and distal coronary sinus electrode, respectively; HBEd/HBEm/HBEp, distal, mid, and proximal electrode of the catheter positioned at the His…

Fig. 3. A. Local activation map and B. voltage map, and C. intracardiac recordings of atrial tachycardia using a multielectrode mapping catheter. A., B.: A centrifugal pattern (i to v) propagating from the EAA (blue circle point) located at the boundary zone between the right atrium and inferior vena cava (red-color code area; <0.05mV in bipolar voltage map) was observed. C.: The potential at the EAA site (asterisk) preceded 105 ms to the P wave onset, QS pattern from the unipolar (dagger), and 0.27 mV from the bipolar electrode, respectively. II, surface ECG leads; CAU, caudal angle; EAA, earliest atrial activation; IVC, inferior vena cava; LA, left atrium; LSPV, left superior pulmonary vein; MAP bi, bipolar electrode from EAA; MAP uni, unipolar electrode from EAA; RAO, right anterior oblique; Ref, reference catheter electrode; RIPV, right inferior pulmonary vein; RSPV, right superior pulmonary vein; SVC, superior vena cava; TA, tricuspid annulus.

Fig. 4. A. Intracardiac recording and B. fluoroscopic image at the successful ablation site.A. The distal tip of the ablation catheter was positioned at the earliest atrial activation (EAA) site during AT (cycle length of 695 ms) obtained from a three-dimensional electroanatomical mapping technique using a multielectrode catheter. Based on the abrupt change in atrial potential sequence obtained from each electrode before (asterisk; EAA site was at CSp) and after (dagger; EAA site was at HRAd), the focal radiofrequency energy application site was used for atrial tachycardia termination. Note no distinct potential was observed from the distal tip of the ablation catheter before RF energy application.B. Angiography of the right atrium shows the position of the ablation site (white arrow head) just below the right atrium-inferior vena carta junction. I/aVF/V1/V5, surface ECG leads; ABLd/ABLp, distal and proximal electrode of the ablation catheter, respectively; CSp/CSm/CSd, proximal, mid, and distal coronary sinus electrode, respectively; HBEd/HBEm/HBEp, distal, mid, and proximal electrode of the catheter positioned at the His bundle recording site, respectively; HRAd/HRAp, distal and…