1. Volume 13, Issue 10, Pages 2048-2055 (October 2016)
Evaluation of a novel high-resolution mapping technology for ablation of recurrent scar- related atrial tachycardias 
Elad Anter, MD, Thomas H. McElderry, MD, Fernando M. Contreras-Valdes, MD, Jianqing Li, MD, Patricia Tung, MD, Eran Leshem, MD, MHA, Charles I. Haffajee, MD, Hiroshi Nakagawa, MD, PhD, Mark E. Josephson, MD 
Heart Rhythm 
Volume 13, Issue 10, Pages (October 2016)
DOI: /j.hrthm
Copyright © 2016 Heart Rhythm Society Terms and Conditions

2. Figure 1
Local time annotation of complex electrograms. This figure demonstrates the method of local time (activation time) annotation using a combination of bipolar (Bi) and unipolar (Uni) electrograms. The left panel shows activation time annotation of a normal triphasic electrogram during atrial tachycardia. Activation time is annotated at the dV/dtmax of the Uni electrogram, coinciding with the peak of the Bi electrogram (dashed yellow line). The middle panel shows activation time annotation of a fractionated electrogram during atypical left atrial flutter. The Bi electrogram contains 2 separate components marked with yellow and red arrows. The second component of the Bi electrogram (red arrow) coincides with the dV/dtmax of Uni2, marking the local activation timing (dashed yellow line). The right panel demonstrates the local activation time of a split electrogram during atrial tachycardia (yellow and red arrows). The local activation time coincides with the dV/dtmax of Uni1, marking the local activation timing. CSp = proximal coronary sinus; CSm = middle coronary sinus; CSd = distal coronary sinus.
Heart Rhythm  , DOI: ( /j.hrthm )
Copyright © 2016 Heart Rhythm Society Terms and Conditions

3. Figure 2
Activation map of scar-related atrial tachycardia. Figure-of-eight scar-mediated reentrant atrial tachycardia. The lower panel shows 3 electrocardiographic leads and electrograms of a decapolar catheter positioned in the coronary sinus (CS). The tachycardia had a stable beat-to-beat cycle length variability as shown. The left upper panel shows a bipolar voltage map in the anterior-posterior view. The voltage map demonstrates an extensive area of low voltage (purple represents bipolar voltage >0.5 mV; red represents bipolar voltage <0.1 mV). The right panel shows an activation map of the figure-of-eight reentrant circuit. The circuit had a common channel (isthmus) on the septum with an orthodromic wavefront propagating in the superior to inferior axis. At the exit, the wavefront split into 2, with one wavefront propagating around the left atrial appendage (LAA) and left superior pulmonary vein (LSPV) and a second wavefront propagating around the right pulmonary veins. This figure-of-eight circuit had a stable beat-to-beat cycle length variability (lower left panel). Mid-diastolic electrograms were recorded in the common channel (lower right panel). Entrainment demonstrating concealed fusion of the CS electrogram and a post-pacing interval that was 4 ms longer than the tachycardia cycle length, consistent with an isthmus site. The tachycardia slowed and terminated with 2 radiofrequency applications at the common channel (patient 11). MA = mitral annulus; RSPV = right superior pulmonary vein.
Heart Rhythm  , DOI: ( /j.hrthm )
Copyright © 2016 Heart Rhythm Society Terms and Conditions

4. Figure 3
Activation map of scar-related atrial tachycardia. Activation map of scar-related reentrant atypical left atrial flutter. The patient underwent sequential mapping with CARTO 3 and Rhythmia during the same procedure. The upper panel shows an activation map created using CARTO 3 and a PentaRay catheter. The entire tachycardia cycle length was mapped with acquisition of 2270 points. The left upper panel is suggestive of a reentrant circuit around the right inferior pulmonary vein, demonstrating a site of “early meet late.” However, entrainment from this site showed manifest P-wave fusion with a post-pacing interval that was 60 ms longer than the tachycardia cycle length, inconsistent with a reentrant circuit at this site. The mapping window (100% tachycardia cycle length) was then shifted from P-wave onset to mid P wave and led to a shift in the activation map with multiple sites of “early meet late” in and around the ridge between the left pulmonary vein and the appendage (right upper panel). The lower panel shows an activation map created using Rhythmia. The entire tachycardia cycle length was mapped to the left atrium with acquisition of 16,341 points. The activation map was consistent with a clockwise mitral annular flutter. Entrainment from the mitral annulus demonstrated concealed P-wave fusion and a post-pacing interval that was 2 ms longer than the tachycardia cycle length. Ablation at the mitral annulus terminated the tachycardia (patient 17).
Heart Rhythm  , DOI: ( /j.hrthm )
Copyright © 2016 Heart Rhythm Society Terms and Conditions

5. Figure 4
Voltage and activation map of scar-related atrial tachycardia. The upper panel shows mapping of atrial tachycardia with a cycle length of 260 ms using EnSite mapping system and a Lasso catheter. The left upper panel shows a bipolar voltage map demonstrating significant left atrial scar. The right upper panel shows an activation map suggestive of either a reentrant tachycardia with a broad area of “early meets late” between the base of the appendage and the mitral annulus (MA) or a focal tachycardia. Ablation at this broad area terminated the tachycardia; however, the patient developed recurrence of a similar tachycardia. The lower panel shows mapping of the tachycardia using Rhythmia. The left lower panel shows a bipolar voltage map demonstrating a similar left atrial scar. The right lower panel shows an activation map demonstrating a single loop reentrant tachycardia at the ridge between the left superior pulmonary vein and the appendage. Ablation at this location terminated the tachycardia (Online Supplemental Figure 1) (patient 11).
Heart Rhythm  , DOI: ( /j.hrthm )
Copyright © 2016 Heart Rhythm Society Terms and Conditions

6. Figure 5
Utility of high-resolution mapping in determining arrhythmia mechanisms. The left panel shows a right atrial activation map of atrial tachycardia in a patient with a history of atrial septal defect (ASD) repair. The map created with CARTO 3 is suggestive of a focal mechanism with a point source centrifugal activation pattern. The same arrhythmia was then mapped with Rhythmia (middle panel). The activation map is consistent with reentrant excitation around the surgical ASD patch. Entrainment from the circumference of the patch demonstrated concealed fusion with a post-pacing interval that was equal to the tachycardia cycle length. Ablation from the superior aspect of the patch to the superior vena cava (SVC) slowed and terminated the tachycardia. The right panel shows the corresponding bipolar voltage map (range 0.1–0.5 mV) with scar at the site of the patch (patient 10). TVA = tricuspid annulus.
Heart Rhythm  , DOI: ( /j.hrthm )
Copyright © 2016 Heart Rhythm Society Terms and Conditions