Hypoxemia, Dyspnea, and Exercise Tolerance in Patients With Pulmonary Arteriovenous Malformations
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 39
- 试验地点
- 2
- 主要终点
- Total body oxygen consumption in mls/min/kg, at peak exercise (VO2 max).
研究概览
简要总结
Pulmonary arteriovenous malformations (PAVMs) are a rare vascular condition affecting the lungs. PAVMs lead to low blood oxygen levels, yet are very well tolerated by patients. This study will examine the exercise capacity of PAVM patients using formal cardiopulmonary exercise tests performed on a stationary bicycle.
详细描述
It is well known that the lung is the site at which oxygen enters the blood stream, diffusing from the alveolar air sacs into the pulmonary capillaries. This newly oxygenated blood is carried to the heart in the pulmonary veins, then passes into the systemic circulation to provide oxygen to the tissues.
Patients with pulmonary arteriovenous malformations (PAVMs) have abnormal vascular connections between pulmonary arteries and pulmonary veins in the lung. Blood flowing through PAVMs therefore bypasses the oxygenation sites in the pulmonary capillaries. Low blood oxygen levels (hypoxemia) is frequent in PAVM patients but breathlessness (dyspnea) is not. The investigators have shown that dyspnea was not a common presenting complaint in a large UK series, and that there is little correlation between severity of dyspnea in PAVM patients, and blood oxygen levels.
In this study the investigators will address the question "Why are hypoxemic PAVM patients not more dyspneic?"
The investigators will address this by first performing standardised cardiopulmonary exercise testing, as used in the clinic, on age and sex matched patients with PAVMs and healthy controls. Physiological parameters will be compared, to test the null hypothesis that the impact of exercise on PAVM patients' cardiopulmonary systems does not differ to normal controls.
If the expected differences are confirmed, the investigators will examine if there is any difference to normals by re-examining the exercise tolerance of the PAVM cohort after they have had their PAVMs treated by embolization.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Single Group
- 主要目的
- Supportive Care
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Ability to provide informed consent
- •Healthy volunteers: no concurrent health reason to avoid exercise
- •Pulmonary AVMs: pulmonary AVMs confirmed by CT scan
- •Hereditary hemorrhagic telangiectasia without pulmonary AVMs: HHT according to current international consensus criteria, with no evidence of PAVMs on dedicated thoracic CT scan.
排除标准
- •Inability to provide informed consent.
- •Any known cardiovascular abnormality including a history of syncope (faintness, dizziness, lightheadedness or loss of consciousness due to an abnormality of the cardiovascular system).
- •Current respiratory tract infection (eg a cold).
- •Pregnancy.
- •Claustrophobia or needle phobia
结局指标
主要结局
Total body oxygen consumption in mls/min/kg, at peak exercise (VO2 max).
时间窗: Same day (Day 1), at end of exercise study
Of the many measurements and derived indices that can be measured during cardiopulmonary exercise testing, the peak consumption of oxygen (VO2 max) is perhaps the best indicator of integrated cardiorespiratory capacity. The principle research question will therefore test the null hypothesis that "The VO2 max does not differ between PAVM patients and age matched healthy controls."
次要结局
- Breathing reserve (%)(Same day (Day 1) at end of exercise test)
- Ventilatory efficiency, derived from the VE / CO2 slope (L/min/L/min)(Same day (Day 1), at end of exercise study)