Incomplete ablation as a mechanism of atrial fibrillation recurrence and atrial tachycardia development after maze procedure

Figures

• 

  Endocardial and additional epicardial cryoablation ensure encircling necrosis of the CS.

• 

  Figure 1. Results of electrophysiologic study in patients with atrial tachyarrhythmia after the maze procedure. The left pie graph shows the results of the study and the right bar graph shows the lesion of incomplete ablation with blue and green bars as sole incomplete ablation mechanism and mixed with non-PV focal mechanism, respectively. See text for details. PV, Pulmonary vein; EPS, electrophysiologic study; PVI, pulmonary vein isolation; CS, coronary sinus.

• 

  Figure 2. Activation maps of atrial tachyarrhythmia caused by incomplete CS ablation. The electroanatomical maps present the left lateral and posterior views of the left atrial endocardium, representing a reentrant activation around the mitral valve orifice conducting through the CS musculature as indicated by red arrows. The activation wavefronts are color coded. The dotted lines indicate a bottom ablation line, connecting the right and left PVI, and an ablation line extended to the mitral valve annuls. The activation is blocked by the ablation line extended to the mitral valve annuls, but conducts through the incompletely ablated CS musculature and forms a reentrant circuit around the mitral valve orifice. CS, Coronary sinus; PVI, pulmonary vein isolation; RPVs, right pulmonary veins; LPVs, left pulmonary veins; MVO, mitral valve orifice.

• 

  Figure 3. Endocardial and epicardial cryoablation for completely encircling necrosis of the CS. The schemas represent long axis cross-section views of the posterior LA and the posterior LV. The left panel shows an endocardial cryothermia with a cryoprobe, applied on the posterior LA with the tip of the probe positioned at the mitral valve annulus, ablating the endocardial side of the CS, while the epicardial side of the CS is not completely ablated. The right panel shows an additional cryothermia of the CS epicardium results in completely encircling necrosis of the CS. CS, Coronary sinus; LA, left atrium; LV, left ventricle; PML, posterior mitral valve leaflet; CA, coronary artery.

• 

  Figure 4. Impact of additional epicardial ablation on postoperative AT development. The incidences of postoperative AT development in the patients who underwent CS ablation with a clamp-type bipolar radiofrequency device (N = 301) were presented as a bar graph for the patients with nonperformance of additional epicardial CS ablation (none), those with an additional epicardial cryoablation, and with an RF ablation. Blue-, red-, and green-colored boxes indicate postoperative SR, AF, and AT, respectively. The number indicates number of patients. See text for details. AT, Atrial tachycardia; CS, coronary sinus; RF, radiofrequency; SR, sinus rhythm; AF, atrial fibrillation; N.S., not significant.

• 

  Figure E1. Locations of non-PV foci with number of patients. The locations of non-PV foci are plotted on the atrial schemas in the left panel. Each schema indicates the upper epicardial and posterior epicardial views of the atria, and the right atrial view of the interatrial septum. Black dots indicate the location of focal activation. The right table shows the number of patients with each location of non-PV focus. PV, Pulmonary vein; LAA, left atrial appendage; MV, mitral valve; TV, tricuspid valve; SVC, superior vena cava; RAA, right atrial appendage; IVC, inferior vena cava; FO, fossa ovalis; CS, coronary sinus; SAN, sinoatrial node; RA, right atrium.