The Impact of Accelerated Pacing and AV-delay Regulation on the Pulmonary Capillary Wedge Pressure During Exercise in Patients With HFpEF
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 20
- 试验地点
- 2
- 主要终点
- Pulmonary capillary wedge pressure (PCWP), measured using a Swan-Ganz catheter (pulmonary artery catheter).
研究概览
简要总结
What is HFpEF? In heart failure with preserved ejection fraction (HFpEF), the heart pumps well but struggles to relax and fill with blood between beats. This raises the pressure inside the heart, especially during physical activity, causing symptoms like shortness of breath and fatigue - even with light activities like walking or climbing stairs.
What is this study about? Recent research suggests that a higher heart rate may help lower this elevated pressure. Many HFpEF patients already have a pacemaker. This study investigates whether simply increasing the pacemaker rate during light exercise can reduce the pressure in the heart.
How does the study work? We wille measure heart pressures in 20 patients in rest and while cycling using a heart catheter and monitor their breathing. Throughout these measurements, we will gradually increase the pacemaker rate step by step.
Why does this matter? If a higher pacemaker rate successfully lowers heart pressure, this could offer a simple, drug-free way to improve daily functioning and comfort for thousands of patients with HFpEF, justifying further long-term studies to evaluate effects beyond the immediate changes in heart pressures.
详细描述
First, we will review patient records to identify eligible participants, who will then be contacted during their regular check-up visit. If they are interested in participating, they will be invited for an additional screening visit if needed.
Patients who meet the eligibility criteria will be invited for an invasive exercise test. At this visit, two small tubes (catheters) will be placed, one in a neck vein and one in a wrist artery, to measure heart pressures and blood oxygen levels. The patient then sits on a reclined stationary bike, wearing a breathing mask to monitor oxygen uptake. Throughout the visit, ultrasound measurements of the heart will also be performed.
First, heart pressures are measured at rest while the pacemaker rate is gradually increased in three steps (+20, +40, +60 beats per minute). Second, the patient cycles gently while the same measurements are repeated, with the pacemaker rate increased in three steps (+10, +30, +50 beats per minute). In a final step of both the rest and exercise protocol, the heart rate will return to the level associated with the lowest heart pressure, and blood oxygen levels will be checked, allowing the research team to calculate how many liters of blood the heart pumps per minute. Afterward, the catheters are safely removed and the pacemaker settings are restored to their original values. This visit is expected to last about three hours, after which study participation ends.
The full study is expected to be completed once 20 patients have finished all study tests.
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
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
- •inclusion: decompensated heart failure, unstable coronary syndrome
- •Contraindication to central venous access
- •Severe coagulopathy (e.g., spontaneous INR > 2, thrombocytopenia < 50,000/µL)
- •Local infection or skin infection at the insertion site
- •Thrombosis or anatomical abnormalities of the right jugular vein
- •Pneumothorax or contralateral lung pathology
- •Inability to properly position the patient
- •Contraindication to arterial access
- •Thrombosis or occlusion of the target artery
- •Raynaud's phenomenon or other vasospastic disorders
- •Active infection at the intended insertion site
- •Severe coagulopathy (e.g., spontaneous INR > 2, thrombocytopenia < 50,000/µL)
- •Insufficient collateral circulation (e.g., inadequate perfusion in an Allen test)
- •Contraindications to CPET
- •ECG signifying myocardial injury
- •ECG signifying current or potentially lethal arrhythmias
- •Systemic hypotension (e.g. systolic blood pressure < 90 mmHg)
- •Extreme hypertension (e.g. systolic blood pressure > 220 mmHg)
- •Syncope, presyncope, or lightheadedness
- •SaO2 < 88%
- •Severely elevated PCWP (> 40 mmHg) during exercise
排除标准
- 未提供
研究组 & 干预措施
All patients
干预措施: Accelerated pacing with AV-delay optimization during rest and light intensity cycling (Other)
结局指标
主要结局
Pulmonary capillary wedge pressure (PCWP), measured using a Swan-Ganz catheter (pulmonary artery catheter).
时间窗: Intraprocedural
The change in PCWP at each pacing frequency (+20 bpm, +40 bpm, +60 bpm) with its corresponding optimal AV-delay at rest, compared to baseline PCWP. The change in PCWP at each pacing frequency (+10 bpm, +30 bpm, +50 bpm) using dynamic AV-delay programming, while avoiding truncation, compared to baseline PCWP during exercise (cycle ergometry at 25 W) Baseline PCWP is calculated as the average of the measurements before and after each accelerated pacing-on step, using the intrinsic HR or baseline atrial pacing rate as the reference HR, as applicable
次要结局
- Cardiac output, measured using the direct Fick principle(Intraprocedural)
- Shear wave velocity, measured via echocardiographically obtained myocardial shear waves following mitral valve closure(Intraprocedural)
- Peripheral oxygen extraction(Intraprocedural)