1. Radial approach: a new concept in surgical treatment for atrial fibrillation. II. Electrophysiologic effects and atrial contribution to ventricular filling 
Takashi Nitta, MD, Richard Lee, MD, Hiroshi Watanabe, MD, Kevin M Harris, MD, John M Erikson, MD, Richard B Schuessler, PhD, John P Boineau, MD, James L Cox, MD 
The Annals of Thoracic Surgery 
Volume 67, Issue 1, Pages (January 1999)
DOI: /S (98)

2. Fig 1
Electrode molds used in the present study. The atria were mapped endocardially with 212 unipolar electrodes mounted on a molded sponge designed to fit the postoperative atria. One hundred four electrodes were mounted on the right atrial mold and 108 electrodes on the left atrial mold. The electrode molds were inserted into each atrium across the atrioventricular valve retrogradely through ventriculotomy procedures during cardiopulmonary bypass in study animals. The electrode molds are shown as if the atrial endocardial surfaces are observed from the back. (IVC = inferior vena cava; LA = left atrium; LLPV = left lower pulmonary vein; LUPV = left upper pulmonary vein; MV = mitral valve; RA = right atrium; RAA = right atrial appendage; SVC = superior vena cava; TV = tricuspid valve.)
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )

3. Fig 2
Duration of AF induced before (Pre Op) and 6 weeks after (Post Op) the radial approach (solid circles) and the maze procedure (open circles).
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )

4. Fig 3
Atrial burst pacing to induce AF. Preoperative (PRE-OP) burst pacing at a cycle length of 100 ms induced AF, which was sustained for 18 seconds. Six weeks after the radial approach, burst pacing at the same cycle length did not induce sustained AF and resulted in only a brief period (<1 second) of atrial repetitive responses. (ECG = electrocardiogram; POST-OP = after surgical treatment; RA-EGM = right atrial electrogram; RR = repetitive responses; SR = sinus rhythm.)
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )

5. Fig 4
Atrial endocardial maps during sinus rhythm 6 weeks after the radial approach. The boxed area on the electrocardiogram (ECG) is the data window analyzed to construct the activation map. The wide QRS configuration in the electrocardiogram was the consequence of the ventriculotomy procedures. The two middle maps represent the lateral (LAT) and septal (SEPT) surfaces of the right atrial (RA) endocardium. The three lower maps represent the left lateral, inferior (INF), and septal aspects of the left atrium (LA). The sinus node is indicated as an oval on the right atrium at the superior vena caval (SVC) junction. The border of the interatrial septum is denoted as dashed lines. The activation sequence is indicated by arrows. The asterisk in the left atrial septum indicates the earliest activation site of the left atrial endocardium. Atrial incisions are shown, and cryolesions are denoted as small dark circles. Numbers represent the activation times associated with each wavefront (wavy lines) and together depict the activation sequence. (CS, coronary sinus; FO, fossa ovalis; LAA = left atrial appendage; L.LAT = left lateral; RPVs, right pulmonary veins; other abbreviations are as in Fig 1.)
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )

6. Fig 5
Atrial endocardial maps during sinus rhythm 6 weeks after the maze procedure. The shaded area denotes the electrically isolated region. (Symbols and abbreviations are as in Fig 4.)
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )

7. Fig 6
Microscopic photographs of a cross section of the posterior atrial septum after the maze procedure (left panel) and the radial approach (right panel). Note that a large part of the atrial septum was scarred after the maze procedure, whereas most of the septum was preserved after the radial approach. (LA = left atrium; RA = right atrium.)
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )

8. Fig 7
Temporal distribution of atrial activation during sinus rhythm in a sham dog and in dogs after the radial approach and the maze procedure. Histograms represent the number of electrodes activated during each 10-ms period. Open bars indicate right atrial activation; solid bars indicate left atrial activation. See text for explanation.
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )

9. Fig 8
Total activation times of the right and left atria during right atrial pacing after the radial approach and the maze procedure. (NS = not significant.)
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )

10. Fig 9
Doppler flow tracing across the mitral valve after the radial approach (upper panel) and the maze procedure (lower panel). Note that the peak velocity and the area under the curve of the A wave are larger in the radial approach than in the maze procedure. (E and A = Doppler flow during early and atrial filling of the left ventricle, respectively.)
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )

11. Fig 10
Ratio of the peak velocity of the E wave to A wave (peak E/A) across the mitral valve after the maze procedure and the radial approach. The horizontal line and the shaded zone represent the average and the range (within 1 standard deviation) of peak E/A in normal dogs. Peak E/A after the radial approach was significantly smaller than after the maze procedure (p < 0.05). (NS = not significant.)
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )

12. Fig 11
The AFF across the mitral valve after the maze procedure and the radial approach. The AFF for the radial approach is within normal limits for a day. The AFF after the radial approach was significantly larger than that after the maze procedure (p < 0.01). (NS = not significant.)
The Annals of Thoracic Surgery  , 36-50DOI: ( /S (98) )