The comparison of lesion outline and temperature field determined by different ways in atrial radiofrequency ablation

Abstract

BackgroundThe aim of this study is to research the lesion outline and temperature field in different ways in atrial radiofrequency ablation by using finite element method.MethodsThis study used the method which considered the thermal dosage to determine the boundary between viable and dead tissue, and compared to the 50 °C isotherm results in analyzing lesion outline. Besides, we used Hyperbolic equation which considered the relaxation time to calculate the temperature field and contrasted it with Pennes’ bioheat transfer equation.ResultsAs the result of the comparison of the lesion outline, when the ablation time was 120 s, the isotherm of the thermal dosage was larger than the 50 °C isotherm and with the increasing of the voltage the gap increased. When the ablation voltage was 30 V, the 50 °C isotherm was larger than the thermal dosage isotherm when the ablation time was less than 160 s. The isotherms overlapped when the time was 160 s. And when the ablation time was more than 160 s, the 50 °C isotherm was less than the thermal dosage isotherm. As to the temperature field, when the ablation voltage was 30 V with the ablation time 120 s the highest temperature decided by Hyperbolic was 0.761 °C higher. The highest temperature changed with relaxation time. In most cases, the highest temperature of the Hyperbolic was higher otherwise the relaxation time was 30–40 s.ConclusionsIt is better to use CEM43 °C to estimate the lesion outline when the ablative time within 160 s. For temperature distribution, the Hyperbolic reflects the influence of heat transmission speed, so the result is more close to the actual situation.

Differences in applied electrical power between full thorax models and limited-domain models for RF cardiac ablation

“…Likewise, if the model domain reaches 8 cm in radius (sum of zones 1, 2 and 3), the power in the model should be reduced to $84% (21 W). Computational models that do not include the thorax are rarely larger than 8 cm in radius [1][2][3][4][5][6][7][8][9][10][11][12][13]. It is important to point out that our conclusions are equally valid for any applied power, which means they can be applied to highpower ablation models such as those recently proposed [32,33].…”

“…Current density is especially high around the active electrode (due to its small size) and creates a thermal lesion exclusively in the target zone. Computer modeling has been broadly used to study specific issues associated with RFCA [1][2][3][4][5][6][7][8][9][10][11][12][13]. As almost all the models simplify reality by including only a relatively small region around the active electrode, the computational domain includes a zone of cardiac tissue and blood whose size depends on preventing the boundary conditions from affecting the results.…”

“…As almost all the models simplify reality by including only a relatively small region around the active electrode, the computational domain includes a zone of cardiac tissue and blood whose size depends on preventing the boundary conditions from affecting the results. This dimension can range between a distance of from 12 to 75 mm around the active electrode (12 mm [1], 16 mm [2,3], 19 mm [4], 25 mm [5,6], 30 mm [7], 40 mm [8][9][10][11], 44 mm [12], 75 mm [13]). All of these can be considered limited-domain models since they do not include the entire electrical circuit from the active electrode to the dispersive through the thorax tissues (see Figure 1(A)).…”

Preface: Computational and experimental methods for biological research: cardiovascular diseases and beyond

“…Huge effort has been made in many disciplines including medical imaging, computational modeling, biomechanics, bioengineering, medical devices, animal and clinical studies, population studies as well as genomic, molecular, cellular and organ-level studies seeking improved methods for early detection, diagnosis, prevention and treatment of these diseases. Following the success of our special issue last year [1], experts in various disciplines were invited to write papers covering important areas in biomedical research, including medical images [2–5], arteries [6–10], aneurysm [11–14], some heart and lung issues [15–17], medical devices and treatment techniques [18–24], microscale studies at cell and molecule levels [25–28], and others [29–36]. A total of 35 papers were included in this special issue, with a good spectrum of coverage.…”

“…They achieved over 87.5% accuracy, 80% sensitivity, and 95% specificity with support vector machine (SVM). Tian et al [5] provided comparison of lesion outline and temperature field determined by different ways in atrial radiofrequency ablation.…”