1. Radial approach: a new concept in surgical treatment for atrial fibrillation I. Concept, anatomic and physiologic bases and development of a procedure 
Takashi Nitta, MD, Richard Lee, 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
Schema of the concepts of the maze procedure and the radial approach. The large outer circle denotes the atria, and its outer limit is bounded by the atrioventricular annular margins. The small circle indicates the sinoatrial node, and the shaded area indicates the isolated portion of the atrium. Arrows indicate the activation wavefront from the sinoatrial node, radiating toward the annular margins. The atrial coronary arteries, arising at the atrioventricular groove, are also schematically drawn. Note that the radial approach (right panel) preserves a more physiologic activation sequence and preserves blood supply to most atrial segments, whereas the atrial incisions of the maze procedure (left panel) desynchronize the activation sequence, and some of the incisions cross the atrial coronary arteries.
The Annals of Thoracic Surgery  , 27-35DOI: ( /S (98) )

3. Fig 2
Atrial coronary arteries in dogs. The upper panel represents the posterior epicardial aspect of the atria. The sinus node region is denoted as a dashed oval. The lower panel represents the right atrial aspect of the interatrial septum. Upper and posterior borders of the septum are denoted as a dashed line. (Ao = aorta; CS = coronary sinus ostium; FO = fossa ovalis; IVC = inferior vena cava; LAA = left atrial appendage; LCX = left circumflex coronary artery; MS = membranous septum; PA = pulmonary artery; PVs = pulmonary veins; RAA = right atrial appendage; RCA = right coronary artery; SVC = superior vena cava; TT = tendon of Todaro; TV = tricuspid valve; 1 = anterior right atrial artery; 2 = intermediate right atrial artery; 3 = posterior right atrial artery; 4 = anterior left atrial artery; 5 = intermediate left atrial artery; 6 = posterior left atrial artery; 7 = atrioventricular node artery.)
The Annals of Thoracic Surgery  , 27-35DOI: ( /S (98) )

4. Fig 3
Atrial endocardial activation maps during sinus rhythm in a normal dog. The boxed area on the electrocardiogram (ECG) is the data window analyzed to construct the activation maps. The atria were mapped endocardially with 212 unipolar electrodes mounted on sponge forms that were molded to fit the canine atria. The electrode molds were inserted into the atria through biventriculotomies across the atrioventricular valve annuli while the animal was supported by normothermic cardiopulmonary bypass. The wide QRS configuration in the electrocardiogram was the consequence of the ventriculotomies. The two middle maps represent the lateral (LAT) and septal (SEPT) surfaces of the right atrial (RA) endocardium. 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 junction with the superior vena cava (SVC). 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. (L.LAT = left lateral; LLPVs = left lower pulmonary veins; LUPV = left upper pulmonary vein; MV = mitral valve; RPVs = right pulmonary veins; other abbreviations as in Fig 2.)
The Annals of Thoracic Surgery  , 27-35DOI: ( /S (98) )

5. Fig 4
Location of the atrial incisions of the radial approach (right panels) and the maze procedure (left panels), as well as the postoperative activation sequence. Upper, middle, and lower panels represent the superior and posterior epicardium and septum of the atria, respectively. The small dark region of the right atrium at the junction with the superior vena cava (SVC) represents the sinus node. Dashed lines indicate the atrial incisions, and the arrows indicate the activation sequence after the procedures. The darkly shaded regions indicate the excised or isolated regions. The small lightly shaded circles indicate cryolesions. The asterisks in the middle and lower panels are the epicardial and endocardial aspects of the identical sites. (Abbreviations are as in Figs 2 and 3.)
The Annals of Thoracic Surgery  , 27-35DOI: ( /S (98) )

6. Fig 5
Schematic representation of anatomic correlation between the atrial incisions and the atrial activation pattern during sinus rhythm in normal atria and in the atria after the maze procedure or the radial approach. Thick lines represent the surgical incisions and the solid area represents the part of atria that is surgically isolated or excised. Dashed lines represent Bachmann’s bundle between the atrial appendages, the interatrial septum, and the crista terminalis. Arrows indicate the activation sequence. (AVN = atrioventricular node; SAN = sinoatrial node; other abbreviations are as in Fig 2.)
The Annals of Thoracic Surgery  , 27-35DOI: ( /S (98) )