New Discovery of Left Atrial Macroreentry Tachycardia: Originating from the Spontaneous Scarring of Left Atrial Anterior Wall

Figure 2

The electrophysiological characteristics of arrhythmogenic substrate. Left atrial activation maps of a patient (a–c) with a double-loop reentry by a critical isthmus (a, c, black dotted lines), which is shown through early meet late in CARTO 3 V6 (action time of more than 25 percent of the TCL between adjacent points indicates block lines (a, red boxes)). The electrograms and conduction velocities of isthmus are shown and selected for ablation (a, white boxes). In contrast, the conventional anatomical isthmus located at the mitral isthmus exhibited normal electrogram characteristics (b, white boxes). The voltage maps (purple ≥ 0.45 mV; red: <0.1 mV) characterized by a central scar at the mid anterior level (c, e). A patient presented with single-loop reentry, and a clockwise loop revolved around the right pulmonary vein (d, e). The isthmus (black dotted lines) located between LAAW scar and the roof adjacent to the RSPV. Tachycardia was terminated in 10 seconds by ablation of the isthmus, where it showed a conduction slowing highly fractionated electrograms (d, e, white boxes) (see Supplementary Material Video 1,2). LAA: left atrial appendage; MV: mitral valve; LSPV: left superior pulmonary vein; RSPV: right superior pulmonary vein; RPV: right pulmonary vein; LAAW: left atrial anterior wall.