Ultrasonic characterization of myocardial photocoagulation lesion size in vivo during Nd:YAG laser irradiation
✍ Scribed by Robert Splinter; Jan R. Tuntelde; Chi Hui Chuang; Michelle Thompson; Laszlo Littmann; Robert H. Svenson; Kathy R. Dezern; George P. Tatsis
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 900 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0091-2751
No coin nor oath required. For personal study only.
✦ Synopsis
Endocardial coagulation lesions were created using transcatheter continuous-wave NdYAG laser irradiation. Ultrasound monitoring of thermal lesion dimensions was performed using 7.5-MHz and 10-MHz transducers directly from the epicardial surface in short-axis configuration (group A) or through the chest wall (group B). A total of 33 lesions were created in 10 dogs at energy levels ranging from 300 J to 1000 J.
Mean histological lesion width (HW) compared with ultrasonically determined mean width (UW) showed that the differences (mean -t standard deviation) in group A (UW -HW) was = 1.14 t 0.8 mm, which was not statistically significantly different from zero. In group B, (UW -HW) = 2.04 mm -+ 0.7 mm ( p < .05), which was statistically significantly different from zero. Mean histological depth (HD) differentially related to ultrasound mean depth (UD) for group A and B combined showed (UD -HD) = -0.19 mm t 0.46 mm, not statistically significantly different from zero.
The frequency distribution for width in group A showed [ UW -HW 1 > 3 mm in 32% of cases. In group B 1 UW -HW 1 > 3 mm in 15%, whereas ultrasound width was larger than histology in 75% of the cases. For depth, I UD -HD 1 > 3 mm in 15% of cases.
With further refinement of the technique, ultrasonic tissue characterization may become a useful adjunct to monitoring lesion dimensions during transcatheter laser photocoagulation. 0 1994 John Wiley & Sons, Inc. indexingwords: Canine . Coagulation tion . Histology Recently, there has been a growing interest in the use of lasers for deep-tissue photocoagulation. To be able to deliver the optimal amount of energy, it is essential to achieve real-time monitoring of lesion development.' There is special interest in the treatment of drug-resistant ventricular tachycardia with continuous-wave Nd:YAG laser photoco- agulation of myocardial Determining the development and size of the thermal injury lesion is important for the success of the treatment. Arrhythmogenic foci can be located at epi-~ ~~ From the Laser and Applied Technologies Laboratory, and Carolinas Heart Institute, Carolinas Medical Center, Charlotte, North Carolina. For reprints contact Robert Splinter,