Shunt Quantification in Atrial Septal Defect Using Inert Gas Rebreathing and Thoracic Bioimpedance: Comparison With the Gold Standard Method
试验速览
- 阶段
- 不适用
- 状态
- 终止
- 发起方
- 入组人数
- 10
- 试验地点
- 2
- 主要终点
- shunt fraction
研究概览
简要总结
Shunt quantification in atrial septal defect (ASD) is estimated by Echocardiography-Doppler, with the pulmonary-to-systemic blood flow ratio: Qp/Qs. Higher is the ratio, more important is the shunt, and the consequence on right ventricular function. A value higher than 1.5 is one of the criteria for percutaneous closure of Secundum ASD. Maatouk and al. have demonstrated that a shunt fraction (Qp/Qs) over 3 is a predictive factor of an incomplete reversibility of the right ventricular remodeling [1]. Even if the accuracy of Doppler echocardiography is admitted for Qp/Qs measurement, there is still some technical difficulties. Thus, the right cardiac catheterization for O2 consumption measurement by the direct Fick method is used. The major inconvenient is the potential risk of adverse effects. Non-invasive methods have been developed using physical properties (as the thoracic bioimpedance) or inert gas rebreathing technique. Thoracic Bioimpedance (TB) and inert gas rebreathing (IGR) techniques have been studies on healthy individual and different respiratory or cardiac diseases to evaluate the cardiac output (CO). TB and IGR measure the systemic and pulmonary blood flow respectively. Without shunt the pulmonary blood flow is equal to the systemic blood flow.
Thus, Investigator suppose that combine the two techniques in disease with shunt, will allow a quantification of the shunt fraction Qp/Qs as accurate as with the gold standard technique (Fick method and Echocardiography Doppler).
The purpose of the study is to evaluate the feasibility and the accuracy of the non-invasive measurement of the Qp/Qs ratio in secundum ASD using the IGR technique and the TB versus the two gold standard techniques: the Fick method and the Echocardiography-Doppler.
The study hypothesizes that the values of Qp et Qs determined by IGR et TB respectively are in the same range of values that the one determined by gold standard techniques.
详细描述
Shunt quantification and their hemodynamic consequences have a major importance in the evaluation of heart diseases. Atrial septal defect (ASD) has an intracardiac left-to right shunt, leading to an over pulmonary output with ventricular and pulmonary effects. Measurements of the LTR in ASD requires the determination of the pulmonary blood flow (Qp) and the systemic blood flow (Qs).
Two gold standard techniques are usually used to measure the pulmonary to systemic blood flow ratio (Qp/Qs): either invasive by performing a right heart catheterization, with the direct Fick method, or non-invasive by using the Echocardiography-Doppler (ED) First determine by ED by the successively measure of the Qp at the pulmonary annular and the Qs at the aortic annular, this technique is largely available, reproducible and accurate.
However, some limits are pointed with this non-invasive gold standard method: underestimation of shunt quantification in case of large septal defect, the accuracy depends on the operator experience, the lack of precision to measure pulmonary annular area especially on adults leading to a wrong measure of the pulmonary blood flow.
In case of doubt about pulmonary hypertension or difficulties in hemodynamic evaluation, the cardiologists perform a right heart catheterization to measure the CO by the Fick method .
Concerning the other non-invasive approach, thoracic bioimpedance (TB) have been developed in the middle of the twenty-one centuries by Kubiceck to measure cardiovascular parameters in astronauts has been largely study. Moreover, hemodynamic parameters are not stable but varies continuously according to the "hemodynamic state".
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Other
- 盲法
- None
盲法说明
NO MASKING
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
- •cooperate patients over 18 years, having a OS ASD with an indication of interventional closure according to the European Cardiology society guidelines of
- •Patients with significant shunt (signs of right ventricular volume overload) and Pulmonary Vascular Resistance (PVR) <5WU
- •ASD, regardless the size, with suspicion of paradoxal embolism
- •Patients with PVR > or egal 5 WU but <2/3 Systemic Vascular Resistance or Pulmonary Arterial Pressure < 2/3 systemic pressure and evidence of net Left-to Right shunt (Qp/Qs > 1,5)
- •with the French Social Security System
排除标准
- •Pregnant women and breastfeeding women
- •Difficulties of cooperation (patient under assisted ventilation)
- •Chronic Obstructive Pulmonary disease or respiratory failure
- •Complex congenital heart disease
- •Antiplatelet contraindication
- •Patients under protection, vulnerable patients
- •No consent
- •Contraindication of the non-invasive devices
- •Physioflow (Manatec, France): patients with pacemaker, with a cardiorespiratory support and assistance, severe aortic insufficiency
- •Innocor (Innovision, Odense, Denmark): to our knowledge, and according to the user instructions, there is no contraindication
结局指标
主要结局
shunt fraction
时间窗: at 1 hour
Accuracy of Qp/Qs ratio measurements by the double non-invasive technique and the gold standard method (non-invasive: Echocardiography Doppler; invasive: direct Fick method) before interventional closure of ASD
次要结局
- shunt fraction Qp/Qs after closure(at 1 hour)