Effect of Acute Hypoxia on RIght VEntRicular Function. A Single-Center, Double-Blind, Randomized Controlled Cross-Over Trial.
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 18
- 试验地点
- 1
- 主要终点
- Right ventricular free wall strain
研究概览
简要总结
More and more people are engaging in sports in the mountains, including individuals with heart or lung diseases. At the same time, such diseases are becoming more common in Switzerland. At high altitude, less oxygen is available, which places stress on the body-particularly on the heart, which has to pump blood through the lungs. How the heart, especially the right ventricle, in people with past HAPE responds to this stress is still not well understood. Therefore, this study investigates how the heart responds to simulated altitudes of 2,500 m and 4,000 m, both at rest and during light physical activity in patients with past HAPE. The primary objective is to assess how right ventricular function changes under conditions of reduced oxygen availability. In addition, vital signs, changes in blood gases, oxygen levels in blood and tissue and shortness of breath are assessed. The "altitude" is simulated using a special gas mixture that participants inhale. Participants undergo three altitude conditions (490, 2,500, and 4,000 m above sea level). The order of the altitude conditions is assigned at random. The aim is to better understand how the right ventricle and other parameters respond to low-oxygen conditions and how affected patients can be better supported in the future.
详细描述
Outdoor activities in the mountains are becoming increasingly popular. At higher altitudes, the air contains less oxygen, which puts extra strain on the body-especially on the heart. The right side of the heart plays a key role in pumping blood through the lungs and may need to work harder when oxygen levels are low. While the heart's response to long-term altitude exposure is relatively well known, much less is understood about how the heart reacts to short-term (acute) exposure to low oxygen, particularly during light physical activity and in individuals past HAPE.
Participants with past HAPE will be exposed to different oxygen levels that correspond to altitudes of 490 m (near sea level), 2,500 m, and 4,000 m, both at rest and during light cycling exercise. The main focus of the study is to measure changes in right ventricular function, assessed using a non-invasive heart ultrasound technique called speckle-tracking echocardiography. In addition, heart rate, blood pressure, oxygen saturation, and symptoms such as shortness of breath and leg fatigue will be recorded. The study is conducted at a single center and uses a randomized, double-blind, cross-over design, meaning that each participant undergoes all altitude conditions in a random order, and neither the participants nor the investigators know which altitude is being simulated at a given time.
Participants Only adults aged 18-80 years with diagnosed past HAPE will be included. Participants must live below 800 m above sea level and must not have been exposed to higher altitudes for more than 24 hours in the three weeks before participation. Individuals with significant other medical conditions, pregnancy, need for long-term oxygen therapy, or inability to follow the study procedures will be excluded.
Study procedures
Each study visit includes:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Diagnostic
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Signed informed consent
- •Diagnosed or suspicion of past HAPE
- •18-80 years (age group young: 18-39.99 years / age group older: 40-80 years)
- •All sex and genders
- •Living <800m and without altitude exposure > 2500 m and > 24h within the last three weeks
排除标准
- •<18, >80 years old
- •Any other diagnosed cardiopulmonary condition
- •Other clinically significant severe concomitant disease states (e.g. renal, hepatic dysfunction, etc.)
- •Inability to follow the procedures of the study due to language problems, psychological neurological disorders or orthopaedic disorders
- •Participants permanently living >800m and altitude exposure > 2500 m and >24h within the last three weeks
- •Pregnancy: Participants will be asked if pregnant or not, no screening for undetected pregnancy
- •Lactating women
- •Participation in other study with active treatment
研究组 & 干预措施
Arm CBA
The participant receives first normobaric hypoxia representing 4000 m.a.s.l. (C), then normobaric hypoxia equal to 2500 m.a.s.l. (B), then normobaric normoxia (A). Condition A represents the control.
干预措施: Normobaric Hypoxia (Other)
Arm ABC
The participant receives first normobaric normoxia (A), then normobaric hypoxia equal to 2500 m.a.s.l. (B) then normobaric hypoxia representing 4000 m.a.s.l. (C). Condition A represents the control.
干预措施: Normobaric Hypoxia (Other)
Arm ACB
The participant receives first normobaric normoxia (A), then normobaric hypoxia representing 4000 m.a.s.l. (C), then normobaric hypoxia equal to 2500 m.a.s.l. (B). Condition A represents the control.
干预措施: Normobaric Hypoxia (Other)
Arm BAC
The participant receives first normobaric hypoxia equal to 2500 m.a.s.l. (B), then normobaric normoxia (A), then normobaric hypoxia representing 4000 m.a.s.l. (C). Condition A represents the control.
干预措施: Normobaric Hypoxia (Other)
Arm BCA
The participant receives first normobaric hypoxia equal to 2500 m.a.s.l. (B), then normobaric hypoxia representing 4000 m.a.s.l. (C), then normobaric normoxia (A). Condition A represents the control.
干预措施: Normobaric Hypoxia (Other)
Arm CAB
The participant receives first normobaric hypoxia representing 4000 m.a.s.l. (C), then normobaric normoxia (A), then normobaric hypoxia equal to 2500 m.a.s.l. (B). Condition A represents the control.
干预措施: Normobaric Hypoxia (Other)
结局指标
主要结局
Right ventricular free wall strain
时间窗: It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.
The primary endpoint is defined as the right ventricular free wall strain (RVFWS) from condition normobaric normoxia to condition 4000m for group 1 and from normobaric normoxia to condition 2500m for group 2 at rest. RVFWS will be measured by speckle tracking strain analysis according to the guidelines of the European Association of Cardiology. Speckle tracking echocardiography allows to assess the right ventricular volume and true global RV function without relying on geometric assumption and is a valuable clinical bedside tool for assessing myocardial strain. Tomtec software (Philipps) will be used.
次要结局
- Respiratory effort(It will be assessed at baseline and continuously measured during each condition (1 hour resting period and during the 10 minutes cycling).)
- Tricuspid annular plane systolic excursion (TAPSE)(It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.)
- Right ventricular-arterial coupling(It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.)
- RV/PA(It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.)
- Stroke volume(It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.)
- Heart rate(It will be assessed at baseline and continuously measured during each condition (1 hour resting period and during the 10 minutes cycling).)
- Blood pressure(It will be measured at baseline once and during each condition six times: Four times during the resting period (every 15 min) and two times during low load cycling.)
- Borg Rating of Perceived Exertion Scale (CR10)(Measured at baseline and in each condition twice: Once at the end of the resting condition and again at the end of the cycling exercise.)
- Oxygen saturation(It will be assessed at baseline and continuously measured during each condition (1 hour resting period and during the 10 minutes cycling).)
- Lung tissue oxygenation(It will be assessed at baseline and continuously measured during each condition (1 hour resting period and during the 10 minutes cycling).)
- Brain oxygenation(It will be assessed at baseline and continuously measured during the 1 hour resting period during each condition, and during the 10 minutes cycling.)
- Multiomics profiles(A blood sample will be collected during each condition after 1 hour of rest.)
- Arterial blood gas analysis(A blood sample will be collected during each condition after 1 hour of rest.)
- Right ventricular size(It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.)
- End-diastolic diameter(It will be assessed once at baseline in rest and once in each condition after the 1 hour resting period.)
- Fractional area change(It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.)
- Maximal tricuspid regurgitation velocity(It will be assessed once at baseline in rest and during each condition three times: Once after 1 hour in the specific condition at rest, then during the 5 min of 30 Watt cycling and during the 5 min of 60 Watt cycling.)
- Pulmonary acceleration time(It will be assessed once at baseline in rest and once in each condition after the 1 hour resting period.)
- Diastolic dysfunction grade(It will be assessed once at baseline in rest and once in each condition after the 1 hour resting period.)
研究者
Mona Lichtblau
Senior Attending Physician, Department of Pulmonology
University of Zurich