Catheter Ablation Registry

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. Identifier: NCT00005195
Recruitment Status : Completed
First Posted : May 26, 2000
Last Update Posted : March 16, 2016
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)

Brief Summary:
To assess factors associated with safety and efficacy of catheter ablation using direct current or radiofrequency energy for the management of patients with drug and/or pacemaker resistant cardiac arrhythmias.

Condition or disease Intervention/treatment
Cardiovascular Diseases Arrhythmia Heart Diseases Procedure: Catheter ablation

Detailed Description:


Cardiac tachyarrhythmias that are refractory to either conventional or experimental antiarrhythmic therapy, antitachycardia pacemakers, or both, may result in serious symptoms or death. Catheter ablation has been developed as a nonpharmacologic, closed-chest alternative for the management of these patients. The technique was first applied to man in 1981 and reported by both Scheinman et al and Gallagher et al in 1982. Hartzler reported the first catheter ablation procedure for the treatment of ventricular tachycardia in 1983. In that same year, Weber reported the first use of catheter ablation of an accessory atrioventricular pathway. The standard method of energy delivery for closed-chest catheter ablation attempts involved direct current delivered using a defibrillator, but beginning in 1985, radiofrequency energy was employed in man. This promised to revolutionize the field of catheter ablation, because it offered the hope of more precise destruction of tissue, avoided the need for general anesthesia and significantly lowered complication rates, since it did not involve the levels of energy used in direct current attempts.

The Catheter Ablation Registry (CAR) evolved from a pilot study, the Percutaneous Cardiac Mapping and Ablation Registry (PCMAR) formed in 1983. There were scientific limitations in this voluntary registry. Further prospective studies were needed to better define this procedure, and a multicenter international prospective cohort study was designed to allow a rapid assessment of ablation's dangers and potential usefulness. Results from the study were used to guide physicians as to which patients would and would not benefit from these new procedures.


Data were collected prospectively from sixteen clinical centers in the United States and Europe on attempted catheter ablation of the atrioventricular junction, accessory atrioventricular pathways and ventricular tachycardia. Each of the three ablation techniques was studied as a separate subset and the two methods of energy delivery, direct current or radiofrequency energy, were compared within each subset. A standardized protocol was used for direct current ablation and the results of a variety of protocols for the other two procedures and for radiofrequency energy were observed. Patients were evaluated quarterly in the first post-procedure year, and biannually for the subsequent duration of the study. Statistical analyses were performed to determine the distribution of specific patient characteristics such as age, sex, clinical status, underlying heart disease, and a variety of procedural categories including energy level, mapping data, and catheter position. A determination was made of the frequency of successful outcomes including cessation of arrhythmias, production of third degree atrioventricular block, and disappearance of symptoms and of adverse effects, including procedure-related complications and death.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

Study Type : Observational
Study Start Date : September 1986
Actual Study Completion Date : August 1991

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Ages Eligible for Study:   up to 100 Years   (Child, Adult, Older Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No
No eligibility criteria