Abstract
PurposeThe aims of this study were to develop an experimental procedure for setting the catheter angle with respect to the surface of the heart muscle and the catheter contact force and to investigate the catheter contact area on the heart muscle as a function of catheter contact angle and force.MethodsVisualization tests were performed for 5 contact angles (0°, 30°, 45°, 60°, and 90°) and 8 contact forces (2, 4, 6, 10, 15, 20, 30, and 40 gf). Each experiment was repeated 6 times with 2 different commercially available catheter tips.ResultsThe morphology of the contact area was classified into rectangular, circular, ellipsoidal, and semi-ellipsoidal. The correlation between contact force and contact area was a logarithmic function; increasing contact force was associated with increased contact area. At the same contact force, the correlation between contact angle and contact area was inverse; decreasing contact angle was associated with a corresponding increase in contact area.ConclusionBoth the catheter contact angle and contact force substantially impact the contact area and morphology in catheter ablation procedures.
Highlights
IntroductionOver the past three decades, cardiac catheter ablation therapy has become a widely used and effective treatment for tachyarrhythmia. In this treatment, radiofrequency current is applied to the heart, heating the target area to a temperature exceeding 50 °C through resistive heating, thereby creating a lesion that isolates the abnormal electric pathway. Earlier studies have revealed several factors that correlate with lesion size, evaluated in terms of ablated area, volume, and depth. These factors include ablation circuit impedance, electrical power, energy delivery, catheter diameter, exposure time, contact force, ablation electrode temperature, irrigation saline flow amount, and blood flow near the myocardial surface. Among these factors, catheter contact force is reported to show a strongly positive correlation with lesion size.1,3–5,22,27In addition to these factors, we hypothesized that the catheter contact angle with respect to the surface of the heart muscle would have a substantial effect
These images show that the contact angle and shape of the catheter tip can affect the contact area morphology
The morphology differs according to the shape of the catheter tip, even when both are applied at a contact force of 2 gf and a contact angle at 0°
Summary
Over the past three decades, cardiac catheter ablation therapy has become a widely used and effective treatment for tachyarrhythmia. In this treatment, radiofrequency current is applied to the heart, heating the target area to a temperature exceeding 50 °C through resistive heating, thereby creating a lesion that isolates the abnormal electric pathway. Earlier studies have revealed several factors that correlate with lesion size, evaluated in terms of ablated area, volume, and depth. These factors include ablation circuit impedance, electrical power, energy delivery, catheter diameter, exposure time, contact force, ablation electrode temperature, irrigation saline flow amount, and blood flow near the myocardial surface. Among these factors, catheter contact force is reported to show a strongly positive correlation with lesion size.1,3–5,22,27In addition to these factors, we hypothesized that the catheter contact angle with respect to the surface of the heart muscle would have a substantial effect. Over the past three decades, cardiac catheter ablation therapy has become a widely used and effective treatment for tachyarrhythmia.7,9,10,14,24,31 In this treatment, radiofrequency current is applied to the heart, heating the target area to a temperature exceeding 50 °C through resistive heating, thereby creating a lesion that isolates the abnormal electric pathway.. Earlier studies have revealed several factors that correlate with lesion size, evaluated in terms of ablated area, volume, and depth.2,18,28,30 These factors include ablation circuit impedance, electrical power, energy delivery, catheter diameter, exposure time, contact force, ablation electrode temperature, irrigation saline flow amount, and blood flow near the myocardial surface.. These factors include ablation circuit impedance, electrical power, energy delivery, catheter diameter, exposure time, contact force, ablation electrode temperature, irrigation saline flow amount, and blood flow near the myocardial surface.6,11,20,23 Among these factors, catheter contact force is reported to show a strongly positive correlation with lesion size..
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