Resynchronization Therapy in Young Patients With and Without CHD
Condition: Dilated Cardiomyopathy; Pediatric
MeSH terms: Cardiomyopathies; Cardiomyopathy, Dilated
Study type: Observational

Summary: 
      Pacemakers can be attached to one or more than one of the heart chambers. After watching
      pacemakers work over time, doctors have found that the pacemakers that stimulate only one
      chamber of the heart sometimes lead to problems later. These problems may be changes in the
      size and shape of the heart. The heart cannot work as well when some of these changes happen.
      We need to learn more about these changes and how to prevent them. There has not been an easy
      way to do this. A new treatment called Cardiac Resynchronization Therapy (CRT) is associated
      with biventricular pacing where two chambers of the heart are stimulated simultaneously.
      Tissue Doppler Imaging,Tissue Synchronization Imaging and 3 dimensional echocardiography are
      new forms of technology that look at the heart while it works. They are similar to a moving
      x-ray that can watch the heart muscles moving. The movement can be measured. Doctors will
      check for changes that happen over time. This has not been studied in children before because
      this kind of is new to this group of patients. This technology is noninvasive which means it
      can be done from the outside of the body and is painless.

      The hearts of children grow fast. It is important to be able to know if the pacemaker or
      problems from dilated cardiomyopathy are causing any changes in the heart that might cause
      problems. We expect to be able to use information we learn from this study to improve how we
      use pacemakers in the future to avoid problems that can happen over time.
    

Detailed description: 
      Hypothesis H1: Children with DCM. Ventricular dyssynchrony is seen in a majority (over 50%)
      of pediatric patients with DCM.

      Specific aim, SA 1: To describe changes in right and left ventricular function using Tissue
      Synchronization Imaging (TSI),Tissue Doppler Imaging (TDI), 3D echocardiography and
      conventional echocardiogram parameters in children with dilated cardiomyopathy.

      Hypothesis H2: In the pediatric population, clinical signs and symptoms related to dilated
      cardiomyopathy are improved with the use of biventricular pacing.

      Specific aim, SA 2: To quantitate the effects of biventricular pacing therapy on ventricular
      function in children with dilated cardiomyopathy using Tissue Synchronization Imaging
      (TSI),Tissue Doppler Imaging (TDI, 3D echocardiography and conventional echocardiographic
      parameters.

      Research Design and Methods

      Patient population

      The patient population will include children (newborn to 18 years of age) treated for dilated
      cardiomyopathy at Children's Healthcare of Atlanta (Egleston Campus). Patients receiving
      pacemaker therapy and medicinal therapy for DCM will be included. For the purpose of this
      study, dilated cardiomyopathy is defined as an ejection fraction (EF) of <35% with left
      ventricular (LV) dimensions greater that 95% for age. Only patients with normal heart anatomy
      and those with repaired congenital defects that have 4 chambers will be evaluated. Heart
      transplant patients and patients who cannot travel to Children's Healthcare of Atlanta at
      Egleston for follow-up are excluded from this study. Two distinct patient groups will be
      examined:

      Group 1: Patients with the diagnosis of dilated cardiomyopathy. We will divide these patients
      into two subgroups:

      A: New onset DCM patients (defined as patients who have been diagnosed with DCM within the
      past 90 days)

      B: Established DCM patients (defined as patients who have been diagnosed with DCM for more
      than 90 days)

      Group 2: Paced Patients: Patients with a secondary diagnosis of dilated cardiomyopathy due to
      chronic RV pacing who are being evaluated for Biventricular pacemaker implantation. This
      group will also include patients with DCM who have received biventricular pacemakers within
      the last two years.

      The proposed study will be a single center, prospective, pilot evaluation of the ventricular
      effects of DCM and the effect of Biventricular pacing for the treatment of DCM in pediatric
      patients. All patients will be enrolled following referral 1) for implantation of a
      biventricular pacemaker for the treatment of cardiomyopathy or 2) for a research
      echocardiogram due to the diagnosis of dilated cardiomyopathy without pacemaker therapy.
      Inclusion criteria will be those children with dilated cardiomyopathy or children referred
      for biventricular pacemaker implantation or upgrade with the diagnosis of dilated
      cardiomyopathy. All participants will be required to sign an informed consent prior to any
      procedures. We anticipate enrolling 50 patients between March 1, 2005 and February 28, 2006
      for this study: 25 patients in Group 1 and 25 patients in Group 2. This will give us a
      confidence level of 95% with a confidence interval of 4-6.

      Procedures

      Echocardiographic assessment Standard 2-dimensional, M-mode, and Doppler evaluation will be
      performed. We will assess cardiac function using left ventricular shortening (SF) and
      ejection fractions (EF measured by Simpson's Rule). We will also perform tissue
      synchronization imaging (TSI), tissue Doppler imaging (TDI), and 3D echocardiography using
      the GE Vivid 7 and HP echocardiographic systems. These systems will assist investigators in
      determining ventricular function and synchrony.

      In all, study participants will receive echocardiographic assessment at the following time
      points:

      Group 1 (new onset and established DCM patients without pacemakers):

      A) Outpatient with the diagnosis of DCM (no pacemaker)-one echo will be performed at
      baseline/enrollment;

      B) Inpatient with the diagnosis of DCM (no pacemaker)-one echo will be performed within 24
      hours of admission to the hospital, 14 days after admission or at discharge from the hospital
      (whichever comes first), and 3 months 2 weeks after discharge from the hospital.

      Group 2 (DCM patients with pacemakers): One echo will be performed at baseline prior to
      biventricular pacemaker implantation, 14 days after admission or at discharge from the
      hospital (whichever comes first) following biventricular pacemaker implantation, 2 weeks, 1
      month, 3 months, 6 months, 9 months and 12 months 2 weeks after biventricular pacemaker
      implantation.

      Inter-observer variability for each echocardiographic assessment (methods and data analysis)
      will be performed by Drs. Derek Fyfe and Tracy Froehlich in Non-invasive Cardiology.

      Clinical assessment Clinical evaluation, including the collection of concomitant medication
      administration, number of hospitalizations for heart failure and adverse events will be
      performed at each visit. An electrocardiogram (EKG) will be performed at all study visits to
      assess QRS duration. Heart failure functional class will also be collected at every visit
      using the Ross or NYHA classification.
    

Intervention name(s): congestive heart failure patients
Intervention type(s): Other
Intervention description(s): observational echo data on congestive heart failure patients
Observational model: Cohort
Time perspective: Prospective
Keywords: Dilated Cardiomyopathy; Pediatric; Bi-ventricular Pacemaker