Epidemiology of Symptomatic Arrhythmias

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: NCT00005237
Recruitment Status : Completed
First Posted : May 26, 2000
Last Update Posted : February 18, 2016
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)

Brief Summary:
To acquire a better understanding of the spontaneous clinical behavior of paroxysmal tachycardia by studying epidemiologic features of symptomatic tachycardia patients.

Condition or disease
Cardiovascular Diseases Heart Diseases Atrial Fibrillation Arrhythmia Tachycardia Tachycardia, Supraventricular

Detailed Description:


Paroxysmal arrhythmias are a group of disorders in which sudden abnormalities of the cardiac rhythm occur without warning. Despite the abundant information available from studies on the mechanisms of tachycardias, there was hardly a shred of objective data in 1989 to establish how the occurrence of symptomatic tachycardias was influenced by various mechanisms. In fact, there were very few objective data describing the occurrence of symptomatic tachycardia among the patients who were afflicted with various paroxysmal tachycardias. For example, were patients in normal sinus rhythm likely to remain free of their tachycardia for one day, one week, one month, or longer? The suddenness and apparent unpredictability of attacks of paroxysmal tachycardias have been substantial obstacles to quantitative description of their occurrence. These studies used careful documentation of spontaneous tachycardia to establish the epidemiology of symptomatic arrhythmias.


Baseline electrophysiologic methods, including intracardiac recording and programmed electrical stimulation, were used to determine the mechanism of paroxysmal supraventricular tachycardia. All patients had antiarrhythmic medications stopped. In most cases, the diagnosis of atrial fibrillation was established by scalar electrocardiographic criteria. At the time of entry into follow-up each patient was given a cardiobeeper and instructed to record and transmit any symptomatic arrhythmia when it occured. Descriptive information about each patient was entered into a baseline data file which included information on the time interval between attacks, age, sex, mechanism of arrhythmia, types of associated heart diseases, ECG data during sinus rhythm, and date and time of call. The purpose of the outpatient follow-up was to obtain objective documentation of spontaneously occurring, symptomatic tachycardia for quantitative analyses. Holter monitoring was used in patients with paroxysmal tachycardias to establish that asymptomatic tachycardia did not occur so often that it constituted an important, unrecognized feature of these clinical conditions.

Ten consecutively referred patients with paroxysmal supraventricular tachycardia and ten consecutively referred patients with atrial fibrillation underwent untreated surveillance with telephone/ cardiobeeper monitoring for symptomatic arrhythmias and had four 24-hour ambulatory ECGs recorded at weekly intervals to detect symptomatic and asymptomatic arrhythmias. The Cox proportional hazards model was used to test the hypothesis that the mechanism of tachycardia was the most important predictor of the tachycardia-free period during an untreated observation period.

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 : December 1988
Study Completion Date : November 1993

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

Pritchett ELC: Afternoon Arrhythmia. Med Aspects Human Sex, 23:16, January 1989 Identifier: NCT00005237     History of Changes
Other Study ID Numbers: 1118
R01HL040392 ( U.S. NIH Grant/Contract )
First Posted: May 26, 2000    Key Record Dates
Last Update Posted: February 18, 2016
Last Verified: May 2000

Additional relevant MeSH terms:
Atrial Fibrillation
Cardiovascular Diseases
Heart Diseases
Tachycardia, Supraventricular
Arrhythmias, Cardiac
Pathologic Processes