Studying the Effectiveness of Pacemaker Therapy in Children Who Have Thickened Heart Muscle

NCT00001960 | Completed Phase 2

• 2 other identifiers: 00000700-H-0007
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Hypertrophic Cardiomyopathy

Keywords

HCM; Pediatric; Pacemaker; Treatment; Symptoms

Interventions

Pacemaker therapy DEVICE

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

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.

Sponsors & Collaborators

• National Heart, Lung, and Blood Institute (NHLBI): lead

Study Sites (1)

National Heart, Lung and Blood Institute (NHLBI)

Bethesda, Maryland, 20892, United States

Location

Related Publications (3)

• Fananapazir L, Chang AC, Epstein SE, McAreavey D. Prognostic determinants in hypertrophic cardiomyopathy. Prospective evaluation of a therapeutic strategy based on clinical, Holter, hemodynamic, and electrophysiological findings. Circulation. 1992 Sep;86(3):730-40. doi: 10.1161/01.cir.86.3.730.

  PMID: 1516184 BACKGROUND

• Wigle ED, Rakowski H, Kimball BP, Williams WG. Hypertrophic cardiomyopathy. Clinical spectrum and treatment. Circulation. 1995 Oct 1;92(7):1680-92. doi: 10.1161/01.cir.92.7.1680.

  PMID: 7671349 BACKGROUND

• Fananapazir L. Advances in molecular genetics and management of hypertrophic cardiomyopathy. JAMA. 1999 May 12;281(18):1746-52. doi: 10.1001/jama.281.18.1746. No abstract available.

  PMID: 10328076 BACKGROUND

MeSH Terms

Conditions

Cardiomyopathy, Hypertrophic

Condition Hierarchy (Ancestors)

Cardiomyopathies; Heart Diseases; Cardiovascular Diseases; Aortic Stenosis, Subvalvular; Aortic Valve Stenosis; Aortic Valve Disease; Heart Valve Diseases

Study Design

• Study Type: interventional
• Phase: phase 2
• Purpose: TREATMENT
• Sponsor Type: NIH

Study Record Dates

• First Submitted: January 18, 2000
• First Posted: January 19, 2000
• Study Start: November 1, 1999
• Study Completion: December 1, 2002
• Last Updated: March 4, 2008

Record last verified: 2002-12

Locations

US (1)