Journal: HeartRhythm Case Reports

Article Title: Cryothermal catheter ablation for focal atrial tachycardia originating from the left atrial appendage: The utility and safety of a soft and flexible multispline mapping catheter for the detailed anatomical evaluation

doi: 10.1016/j.hrcr.2024.05.009

Figure Lengend Snippet: Presentation of case 1. A: Left panel: Sinus rhythm with a heart rate of 67 beats/minute. Right panel: Atrial tachycardia (AT) with a heart rate of 130 beats/minute. B: Activation map of AT using a conventional 3.5-mm-tip catheter during the first procedure performed in another hospital. The earliest activation site (EAS) was the left atrial appendage (LAA). C: Activation map of the AT using a multispline mapping catheter (PentaRay; Biosense Webster Inc, Irvine, CA) in the second procedure. The LAA has 2 distinct lobes; the cyan and magenta triangles indicate the anterior and lateral lobes, respectively. The EAS is the tip of the lateral lobe ( blue tag ). D: Three-dimensional computed tomography image showing 2 distinct lobes, as shown in panel C. E: A tip electrode equipped with PentaRay catheter ( yellow arrow ) allowed the mapping of the distal tip of the LAA, which is the EAS of AT. F: At the EAS, local electrogram ( yellow point ) 102 ms preceding the onset of the P wave ( blue dotted line ). G: Radiography shows 2 distinct lobes, as shown in panels C and D. A circular catheter (Lasso; Biosense Webster Inc) was used as a reference. H: An 8-mm-tip cryothermal catheter (Freezor MAX; Medtronic, Minneapolis, MN) was positioned at the EAS within the LAA. I: Local electrogram ( magenta dotted line ) before cryoablation shows 114 ms preceding the onset of the P wave ( blue dotted line ). J: AT terminated 9 seconds after starting the cryoapplication. CS = coronary sinus; ds = distal; LAO = left anterior oblique; LSPV = left superior pulmonary vein; px = proximal.

Article Snippet: The Freezor MAX was manipulated under fluoroscopic guidance, and the local electrogram was confirmed to be earlier than the OctaRay; thereafter, cryothermal ablation (-80°C, 240 seconds) using an 8-mm-tip catheter (Freezor MAX, Medtronic Inc) successfully abolished the AT ( G– I), without any complications, including phrenic nerve injury.

Techniques: Activation Assay, Computed Tomography

Journal: HeartRhythm Case Reports

Article Title: Cryothermal catheter ablation for focal atrial tachycardia originating from the left atrial appendage: The utility and safety of a soft and flexible multispline mapping catheter for the detailed anatomical evaluation

doi: 10.1016/j.hrcr.2024.05.009

Figure Lengend Snippet: Presentation of case 2. A: Atrial tachycardia (AT) with a heart rate of 139 beats/minute. B: Activation map of the AT using a multispline mapping catheter (OctaRay; Biosense Webster Inc, Irvine, CA). The base of the left atrial appendage (LAA) is the earliest activation site (EAS) ( blue tag ). C: At the EAS, local electrogram ( yellow point ) 85 ms preceding the onset of the P wave ( blue dotted line ). D: Radiography of the LAA during the first procedure. The 3.5-mm-tip ablation catheter was positioned as a reference. E: Cryoablation using a 6-mm-tip cryothermal catheter (Freezor Xtra; Medtronic Inc, Minneapolis, MN) was applied at the EAS within the LAA (first procedure). F: Radiography of the LAA during the second procedure. OctaRay was used as a reference. G: Cryoablation using an 8-mm-tip cryothermal catheter (Freezor MAX; Medtronic Inc) applied at the EAS within the LAA (second procedure). Cyan triangles indicate the earliest splines. H: Local electrogram ( magenta dotted line ) at the EAS 91 ms preceding the onset of the P wave ( blue dotted line ) and the earliest spline of OctaRay ( cyan triangles in panel F). I: AT terminated 22.6 seconds after starting the cryoapplication. AP = anterior-posterior; HB = His bundle; RAO = right anterior oblique; RF cath = radiofrequency catheter; other abbreviations as in Figure 1 .

Article Snippet: The Freezor MAX was manipulated under fluoroscopic guidance, and the local electrogram was confirmed to be earlier than the OctaRay; thereafter, cryothermal ablation (-80°C, 240 seconds) using an 8-mm-tip catheter (Freezor MAX, Medtronic Inc) successfully abolished the AT ( G– I), without any complications, including phrenic nerve injury.

Techniques: Activation Assay