Controlled Cross-Over Study of DDD Pacemaker Therapy in Symptomatic Children With Obstructive Hypertrophic Cardiomyopathy
Pacemaker therapy
Aortic Valve Disease+5
+ Aortic Stenosis, Subvalvular
+ Aortic Valve Stenosis
Treatment Study
Summary
Study start date: November 1, 1999
Actual date on which the first participant was enrolled.Studies suggest that DDD pacemaker therapy is effective in improving symptoms and reducing intra-ventricular pressures and pressure gradients in children with obstructive HCM during a period of rapid body growth when the severity of the disease is expected to worsen. We propose a randomized, cross-over study of DDD pacing versus placebo (AAI pacing mode) in children who have limited exercise performance and/or symptoms despite medical therapy (beta-blocker or verapamil). Study subjects will receive a pacemaker and will be randomized to one of two pacing modes (DDD, AAI). After a 1-year follow-up evaluation the children will cross-over to the alternative pacing mode, and will be re-evaluated after a further year. All children will continue to receive optimum medical therapy (beta-blocker or verapamil) based on improvement in symptoms and exercise performance. The subjects will undergo outpatient evaluations (exercise tests and echocardiography) 3, 6, 15, and 18 months after pacemaker implantation, and inpatient evaluations (exercise tests, echocardiography, and cardiac catheterization) 1 year and 2 years after entry into the study. Primary end-points will be exercise duration and severity of LV outflow obstruction. The patient, parents, referring physician, and individual supervising the exercise tests will be blinded to the pacing mode.
Protocol
This section provides details of the study plan, including how the study is designed and what the study is measuring.50 patients to be enrolled
Total number of participants that the clinical trial aims to recruit.Treatment Study
Eligibility
Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.Any sex
Biological sex of participants that are eligible to enroll.Healthy volunteers not allowed
If individuals who are healthy and do not have the condition being studied can participate.Conditions
Pathology
Criteria
INCLUSION CRITERIA: 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. EXCLUSION CRITERIA: 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.
Study Centers
These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.This study has 1 location
National Heart, Lung and Blood Institute (NHLBI)
Bethesda, United StatesOpen National Heart, Lung and Blood Institute (NHLBI) in Google Maps