Usefulness of the SmartTouch Catheter to Assess the Areas of Myocardial Scar in Patients With Ventricular Tachycardia
试验速览
- 阶段
- 不适用
- 发起方
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- Comparison of the scarred areas obtained by traditional voltage mapping with those obtained using a map that includes the contact force information in patients with VT
研究概览
简要总结
The pressure exerted by the ablation catheter on the tissue has been shown to play an important role on determining the size and the potential efficacy of the ablation lesions. A direct information on the force exerted by the catheter tip obtained from the SmartTouch technology might improve the assessment of the scar areas during electroanatomical mapping in patients with ventricular tachycardia (VT) due to ischemic disease or cardiomyopathy. The objectives of the study are to compare the areas of scar (defined as a low-voltage threshold) obtained from the conventional voltage map with those obtained after the contact map information is available to the operator and to determine if the availability of the contact information allows an improvement of the electroanatomic map by correcting the points taken in no-contact areas. Twenty to 30 consecutive patients with ventricular arrhythmias due to ischemic heart disease or dilated cardiomyopathy undergoing VT ablation will be included in a prospective, one-center, non-randomized study. A voltage map of the left ventricle will be obtained using the CARTO-3 navigation system and the scar areas as well as the areas of potential interest for ablation will be delineated in the standard way and saved as the control map. The force information will be recorded by the system but will not be available to the operator until the control map is saved. Following this step the contact map will be available to the operator to be compared with the control map and further mapping and point acquisition will be allowed to correct the areas previously acquired with poor or no contact. The final map after corrections have been made will be saved as the corrected map. The ablation procedure will then be performed as usual. Both maps will be compared in a deferred way to know how are classified the areas without contact when no pressure information is available, and how many non-contact points are falsely assumed to be low-voltage or dense scar points. These comparisons will give information on how much the standard electroanatomic map can be improved when the force information is added.
详细描述
The usual ablation catheters do not provide direct information on the pressure applied at the contact area of the cardiac structures. However, pressure has been shown to play an important role on determining the size and the potential efficacy of the ablation lesions. The physical contact of the tip of the catheter with the tissue and the force exerted on this tissue are indirectly estimated from other parameters such as the signal voltage, the transmitted force to the other end of the catheter felt by the operator and, in a lesser extent, the circuit impedance.
A widespread technique for ablation of ventricular tachycardias (VT) in patients with cardiomyopathies or ischemic disease consists on the creation of an electroanatomic map to delineate scar areas without electric activity and to look for areas of surviving myocardium inside, at the borders or between the scars, operating as a slow conduction channel in a reentry circuit and playing an essential role in the genesis of VTs. The distinction between scar and normal tissue is predominantly based on the voltage of the unipolar or bipolar electrograms (EGM) recorded at the tip of the ablation catheter. However, the amplitude of the electrogram depends critically on the distance between the electrode and the source of the electric field, in this case the myocardial tissue. The lack of contact between the catheter and the endocardium will reduce the EGM voltage and may induce to interpret a normal EGM point as a low-voltage point, leading to an erroneous delineation of the real scar areas and eventually missing electrically active myocardial paths. Thus a good physical contact between the catheter and the tissue is a prerequisite to obtain a reliable voltage map and to correctly identify scars and areas potentially involved in the VT maintenance. A direct information on the force applied at the tip of the catheter may avoid the interpretation of areas with no-contact induced low-voltage as scars.
Hypothesis.
The hypothesis of the study is that the information on the force exerted by the catheter tip obtained from the SmartTouch technology may improve the assessment of the scar areas during electroanatomical mapping in patients with VT due to ischemic disease or cardiomyopathy.
Study objectives and endpoints.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Consecutive patients with ventricular arrhythmias due to ischemic heart disease or dilated cardiomyopathy undergoing VT ablation
排除标准
- •Age <18 years, absence of signed informed consent or critical clinical status that precludes a detailed mapping procedure
结局指标
主要结局
Comparison of the scarred areas obtained by traditional voltage mapping with those obtained using a map that includes the contact force information in patients with VT
时间窗: During ablation procedure
The size of the scars, the abnormal potentials, and the channels detected in the control map were compared with those of the final map
次要结局
未报告次要终点
研究者
Arcadio Garcia Alberola
Professor of Cardiology
Hospital Universitario Virgen de la Arrixaca