1. Irrigated Radiofrequency Ablation With Transmurality Feedback Reliably Produces Cox Maze Lesions In Vivo 
Chad E. Hamner, MD, D. Dean Potter, MD, Kwang Ree Cho, MD, Alison Lutterman, BS, David Francischelli, MS, Thoralf M. Sundt, MD, Hartzell V. Schaff, MD 
The Annals of Thoracic Surgery 
Volume 80, Issue 6, Pages (December 2005)
DOI: /j.athoracsur
Copyright © 2005 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Representative impedance curve (solid line) and power plot (dashed line) generated during irrigated bipolar radiofrequency ablation. Tissue impedance is continuously monitored between the bipolar electrodes during ablation. A proprietary transmurality feedback program increases ablation power in a stepwise fashion until impedance decline plateaus, predicting lesion transmurality.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2005 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
Schematic representation of the (A) posterior and (B) anterior atrial surface and the Cox maze lesion set used in the study. Endocardial access was obtained through a right atriotomy (I1), left atriotomy (I2), and right atrial counterincision (I3). Six irrigated bipolar lesions were created: B1, superior vena cava (SVC); B2, inferior vena cava (IVC); B3, right atrial body; B4, superior pulmonary veins (PVs); B5, inferior pulmonary veins; and B6, interatrial septum. Four irrigated unipolar lesions were created: U1, mitral isthmus; U2, anterior tricuspid valve; U3, posterior tricuspid valve; and U4, pulmonary vein–connecting lesion. U4 was added only in 2 animals when large left atrial size prohibited B4 and B5 from crossing adequately. (LAA = left atrial appendage; RAA = right atrial appendage.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2005 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
Pacing threshold (current) required to pace the left atrium from the right pulmonary vein at baseline, 1 hour, and 30 days after isolation of the pulmonary veins by irrigated radiofrequency ablation lesions. Functional conduction block was indicated by a fivefold increase in pacing threshold over baseline. *p < 0.001, Student’s t test. Values are means with error bars indicating standard deviations.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2005 The Society of Thoracic Surgeons Terms and Conditions

5. Fig 4
Representative photographs of the left atrium (endocardial view) demonstrating the (A) pulmonary vein (PV) bipolar radiofrequency ablation lesions and (B) mitral isthmus unipolar lesion. Arrows indicate the lesions. Dashed line in A indicates position of the left atriotomy (1% triphenyltetrazolium chloride stain).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2005 The Society of Thoracic Surgeons Terms and Conditions

6. Fig 5
Representative photograph of cross sections from the (A) pulmonary vein bipolar radiofrequency ablation lesions and (B) mitral isthmus unipolar lesion. Arrows indicate the lesions (1% triphenyltetrazolium chloride stain).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2005 The Society of Thoracic Surgeons Terms and Conditions

7. Fig 6
Representative photomicrograph of cross sections from the (A) pulmonary vein bipolar radiofrequency ablation lesions and (B) mitral isthmus unipolar lesion. Arrows indicate the lesions (Masson trichrome stain).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2005 The Society of Thoracic Surgeons Terms and Conditions