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Electromechanical Mapping to Evaluate Heart Muscle

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00001895
First Posted: November 4, 1999
Last Update Posted: March 4, 2008
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
National Institutes of Health Clinical Center (CC)
  Purpose

Patients with narrowed heart arteries who undergo coronary angiography (imaging of the heart's blood vessels) may participate in this "heart mapping" study designed to gain information about the condition of different areas of the heart muscle.

In coronary angiography, a thin tube called a catheter is inserted through a small incision in the groin and pushed up to the heart. There, a contrast dye is injected, revealing areas of blockage in the coronary arteries-the vessels that supply blood to the heart muscle. As soon as the angiography is completed, patients in this study will undergo another procedure called "Biosense mapping." For this procedure, a special catheter with a tiny sensor at the tip will be inserted into the sheath that was used for the angiography and advanced to the heart's main pumping chamber-the left ventricle. The sensor detects the pattern of an electromagnetic field generated from a pad under the patient, and an image of the precise location of the catheter in 3-dimensional space can be seen on a computer screen. The catheter is then navigated to various precise locations in the ventricle, producing an electromechanical map that distinguishes scarred muscle tissue from healthy tissue-information that can be important in guiding treatment.

When this mapping is completed, the patient will be given a drug called dobutamine to increase the heartbeat, and the mapping will be repeated. The heart may also be mapped while the heart rate is increased with a pacing catheter to simulate exercise. The test will be stopped if adverse side effects develop.

Patients in the study will also have magnetic resonance imaging (MRI) and PET (positron emission tomography) scans to get additional information about the heart muscle, such as blood flow and metabolism rate.


Condition Intervention Phase
Myocardial Ischemia Drug: FDG Drug: NH(3) Phase 3

Study Type: Interventional
Study Design: Primary Purpose: Treatment
Official Title: Evaluation of Electromechanical Endocardial Mapping for Assessment of Myocardial Ischemia and Viability

Resource links provided by NLM:


Further study details as provided by National Institutes of Health Clinical Center (CC):

Estimated Enrollment: 71
Study Start Date: August 1999
Estimated Study Completion Date: December 2001
Detailed Description:

A novel left ventricular (LV) mapping system (Biosense, Inc.) uses low-intensity magnetic field energy to determine the location of sensor-tipped catheter electrodes within the LV. On the basis of previous experimental and human studies correlating the extent of myocardial ischemia with the amplitude of electrical signals, we hypothesize that such an integrated LV electromechanical mapping system could be used to distinguish healthy from ischemic or immobile myocardium on the basis of the extent of electromechanical endocardial signals. If this hypothesis is confirmed, the ability to detect on-line myocardial viability and ischemia in the catheterization laboratory may be feasible.

The present study attempts to distinguish between ischemic, immobile, and normal myocardium by comparing LV electromechanical mapping data at rest and during pharmacologic stimulation, with imaging studies using MRI, PET, thallium and echo in patients with coronary artery disease.

  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Senior
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Male or female patients greater than or equal to 21 years undergoing diagnostic cardiac catheterization.

Must not have unstable angina.

No significant unprotected left main disease (greater than 50% stenosis).

No recent myocardial infarction (less than 4 weeks).

Females must not be pregnant or lactating.

No chronic atrial fibrillation.

No prosthetic heart valves.

No significant aortic valve pathology (sclerosis or stenosis) which might prevent retrograde crossing of catheter across the aortic valve.

No left ventricular thrombus seen on echo.

No severe heart failure (NYHA Class 4).

No severe ectopy (greater than 1 every 10 beats) or ventricular tachycardia.

No active infections (fever and elevated white cell count).

Patients will not be considered for this protocol because of contraindications to MRI scan, as stated below:

Pacemaker

Implanted defibrillator

Cerebral aneurysm clips

Swan Ganz catheter with electrodes for a thermistor

Cochlear implants

Insulin pumps

Neural stimulator

  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00001895


Locations
United States, Maryland
National Heart, Lung and Blood Institute (NHLBI)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
  More Information

Publications:
ClinicalTrials.gov Identifier: NCT00001895     History of Changes
Other Study ID Numbers: 990153
99-H-0153
First Submitted: November 3, 1999
First Posted: November 4, 1999
Last Update Posted: March 4, 2008
Last Verified: December 2001

Keywords provided by National Institutes of Health Clinical Center (CC):
Electromechanical Mapping
Myocardial Viability
Myocardial Ischemia
Positron Emission Tomography
Magnetic Resonance Imaging

Additional relevant MeSH terms:
Ischemia
Myocardial Ischemia
Coronary Artery Disease
Pathologic Processes
Heart Diseases
Cardiovascular Diseases
Vascular Diseases
Coronary Disease
Arteriosclerosis
Arterial Occlusive Diseases