Clinical Trials

HomeHomeCurrent Clinical Trials

The Electrophysiologic and Electrocardiographic Changes Associated with Chronic Resynchronization Therapy (CRT)

Study Description

Several studies have suggested that biventricular (BV) pacing might result in an antiarrhythmic effect (1-4). Walker, et al demonstrated a significant decrease in ventricular ectopy with BV pacing when compared to sinus rhythm and right ventricular (RV) pacing in patients with severe congestive heart failure (CHF) (1). Higgins and colleagues demonstrated a reduction in the need for implantable cardioverter defibrillator (ICD) therapy for ventricular arrhythmias in patients treated with chronic biventricular pacing compared to patients with intrinsic conduction (2).

Recently, we demonstrated in a prospective randomized study that acute BV pacing during programmed electrical stimulation resulted in a significant reduction in the induction of ventricular tachycardia when compared to right ventricular-programmed electrical stimulation with no significant effect on ventricular fibrillation induction (4).

The arrhythmia suppression was most likely the result of pre-excitation of the area of slow conduction responsible for the reentrant arrhythmia. Earlier excitation should lead to earlier recovery, thus rendering a premature beat less likely to conduct with delay or block. Abolishing or minimizing such a delay could result in a reduction of reentrant arrhythmias.

While the acute electrophysiologic effects of BV pacing have been evaluated, the electrophysiologic and electrocardiographic changes associated with chronic resynchronization therapy (CRT) remain unknown.  The aim of the following study is to assess these changes.The design of this study requires the delay of BV pacing, or chronic resynchronization therapy (CRT) in a control group of patients.  This carries with it the risk of delaying the potential improvement in CHF associated with this treatment.  The risk resulting from this delay is minimal, as the progression of CHF is a gradual process and there are many patients (over a million by some estimates (5,6)) who are candidates for CRT and are not receiving therapy.  

Contact Information

Status:

Name, Phone, Email:
Brent Hill
801-585-1424
Brent.hill@hsc.utah.edu

Principle Investigator:
Mohamed Hamdan, MD

Please Note:

Study Coordinators and Research Nurses cannot give medical advice over the phone. Telephone numbers are provided for obtaining additional information on specific clinical research trials only. If you have specific questions which require clinical expertise, please call your primary care physician. If you do not have a primary care physician, we can help you find a University of Utah doctor or clinic location to meet your health care needs.

Although the studies described on this Web site may have potential benefits as described, the University of Utah and its physicians and affiliated hospitals cannot and do not guarantee or promise that you will receive any benefits from participating in a study.

Participant Eligibility

Inclusion Criteria:

Subjects undergoing the implantation of a Biventricular Implantable Cardioverter Defibrillator (BV-ICD) will be asked to enroll.

  1. Indication for BV-ICD
  2. Age 18 or older
Exclusion Criteria:
  1. Hypertrophic or restrictive cardiomyopathy
  2. Suspected acute myocarditis
  3. Correctable valvulopathy
  4. An acute coronary syndrome in the past 3 months
  5. Recent coronary revascularization in the past 3 month or scheduled revascularization in the next 3 months
  6. History of paroxysmal or persistent atrial fibrillation, atrial flutter or atrial tachycardia, unless the patient will be undergoing an atrioventricular junction ablation prior to the BV-ICD implantation
  7. Patients admitted due to CHF exacerbation who will receive a BV-ICD during the same hospital admission
  8. Patients with NYHA Class IV heart failure
  9. Inability or unwillingness to return for follow-up visits
  10. Women of childbearing age who could potentially become pregnant

How long does the study run?

5/11/07

Location(s) of the Clinical Trial

 University of Utah Hospital and George E. Wahlen Department of Veterans Affairs Medical Center