Studying the Effectiveness of Pacemaker Therapy in Children Who Have Thickened Heart Muscle
Completed · Phase 2
Conditions studied: Hypertrophic Cardiomyopathy
In brief
A heart condition called hypertrophic cardiomyopathy (HCM) causes abnormal thickening of the heart muscle, which obstructs the flow of blood out of the heart. The thickened muscle and the obstruction of blood flow are believed to cause chest discomfort, breathlessness, fainting, and a sensation of heart pounding. Treatment options for children with HCM include medicine, heart operation, and cardiac transplantation. However, there is no evidence that medicine prevents further thickening of heart muscle; operations carry the risk of death; and donor hearts are not always available. Several studies have shown that pacemaker treatment reduces the obstruction and improves heart complaints in patients with HCM. This study investigates further the efficacy of pacemaker treatment in children. Patients will have exercise tests after treatment with beta blocker and verapamil and will be eligible for the study if heart complaints or reduced exercise performance continue. A pacemaker that treats slow heart rhythms will be inserted. The patient will be sedated and local anesthesia will be administered to numb the area. The procedure takes about an hour. The study will last two years. Patients will be placed on one of two pacemaker programs for the first year and another the second year. At 3- and 6-month follow-up visits, a pacemaker check and echocardiogram will be performed. After 1 year, patients will be admitted to NIH for 2 to 3 days for exercise tests, echocardiogram, and cardiac catheterization. Also, the pacemaker will be changed to the second program. At 15- and 18-month follow-up visits, a pacemaker check and echocardiogram will be performed. After 2 years, patients will again be admitted for 2 to 3 days for exercise tests, echocardiogram, and cardiac catheterization. A pregnancy test will be given to females of child-bearing age before each cardiac catheterization and electrophysiology study. At the end of the study, the pacemaker will be set to the program that worked better. Risks of pacemaker insertion include lung collapse, infection, blood vessel damage, bleeding, heart attack, and death. Risks of cardiac catheterization include infection, bleeding, blood clots, abnormal heart rhythms, perforation of the heart, need for surgery, and death. However, the safety record for both these procedures at NIH has been excellent. The radiation exposure exceeds the NIH radiation guidelines for children, but this exposure in adults has not been associated with any definite adverse effects.
Key facts
- Study ID
- NCT00001960
- Run by
- National Heart, Lung, and Blood Institute (NHLBI)
- People needed
- 50
- Starts
- 1999-11-01
- Expected to finish
- 2002-12-01
- Last updated by the study team
- 2008-03-04
Who can join
Age: any. Sex: any. Healthy volunteers: not accepted.
You may qualify if…
- Children of either gender, aged 4 to 18 years.
- Obstructive HCM defined as LV hypertrophy, and an LV intra-cavitary pressure gradient measured at cardiac catheterization of greater than or equal to 30 mm Hg at rest or greater than or equal to 50 mm Hg following isoproterenol infusion to a heart rate of greater than or equal to 100 beats per minute.
- Cardiac symptoms (chest discomfort, dyspnea, lightheadedness or presyncope, syncope, cardio-respiratory arrest, palpitations, excessive fatigue); and/or exercise duration which is less than 10th percentile predicted for age/gender despite a trial of a beta-blocker therapy and a trial of verapamil therapy.
You may not qualify if…
- Other systemic diseases that prevent assessment by exercise tests and cardiac catheterization.
- Chronic atrial fibrillation.
- Positive pregnancy test: A negative urine pregnancy test will be required before each cardiac catheterization, electrophysiologic study and thallium study. Pregnant or lactating subjects may not participate in the study due to potential teratogenic effects of radiation.
Where it is running
- National Heart, Lung and Blood Institute (NHLBI) — Bethesda, Maryland, United States
Full record on ClinicalTrials.gov
Trial information comes from ClinicalTrials.gov and is refreshed daily. TrialsForMe does not provide medical care and does not run the studies it lists.