Effect of Chronic Changes in Heart Rate on Congestive Heart Failure
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 13
- 试验地点
- 1
- 主要终点
- Ejection Fraction
研究概览
简要总结
This will be a double blind randomized crossover study of patients with congestive heart failure and a heart rate dependent upon a permanent pacemaker. Thus, at all times the heart rate can be maintained at a set rate by adjusting the settings of the pacemaker. Acute and chronic effects of heart rates of 60, 75, and 90 beats per minute will be evaluated. The effect of heart rate will be determined by measuring ejection fraction by nuclear ventriculography, six minute walk distance, and peak oxygen consumption on a maximal exercise test.
详细描述
This study is a double-blind, randomized, cross-over study of patients with congestive heart failure and a heart rate dependent on a permanent pacemaker. Thus, at all times the heart rate can be maintained at a set rate by adjusting the settings of the pacemaker. Acute and chronic effects of heart rates of 60, 75, and 90 beats per minute will be evaluated by primarily comparing cardiopulmonary exercise tests and radionuclide ventriculography scans.
Inclusion Criteria:
Patients must have symptomatic congestive heart failure, NYHA Class II to IV symptoms and an ejection fraction < 40% by nuclear ventriculography within the previous 6 months. Patients must be stable with no change in dosage on conventional therapy (including digoxin, diuretics, ACE inhibitors, hydralazine, nitrates, angiotensin II receptor blockers and/or beta blocker) for at least 4 weeks. Because only heart rate is being evaluated, stable treatment with beta blockade should not prevent evaluation of the effects of changing heart rate.
Patients must have an intrinsic cardiac rate < 60 beats per minute and a functioning permanent pacemaker.
Exclusion Criteria:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
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
- •Patients must have symptomatic congestive heart failure, NYHA Class II to IV symptoms and an ejection fraction < 40% by nuclear ventriculography within the previous 6 months. Patients must be stable with no change in dosage on conventional therapy (including digoxin, diuretics, ACE inhibitors, hydralazine, nitrates, angiotensin II receptor blockers and/or beta blocker) for at least 4 weeks
排除标准
- •active alcohol or illicit drug use
- •myocardial infarction or unstable angina within the previous 3 months
- •obstructive valvular disease
- •exercise induced sustained arrhythmias or symptomatic myocardial ischemia
- •pregnancy
- •psychiatric disorder
- •non-compliance with medical regimen
研究组 & 干预措施
HR=90
Pacemaker set at 90
干预措施: heart rate setting (Device)
HR=60
Pacemaker set at 60
干预措施: heart rate setting (Device)
HR=75
Pacemaker set at 75
干预措施: heart rate setting (Device)
结局指标
主要结局
Ejection Fraction
时间窗: 2 months
Ejection fraction as measured by nuclear ventriculography
次要结局
- Peak Oxygen Consumption(2 months)
- Distance Traveled During a 6 Minute Walk(2 months)
研究者
Stephen Gottlieb
Professor o Medicine
University of Maryland, Baltimore