Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Automatism”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1997

Automatic arrhythmia identification using analysis of the atrioventricular association. Application to a new generation of implantable defibrillators. Participating Centers of the Automatic Recognition of Arrhythmia Study Group.

BACKGROUND: Atrioventricular association is a key criterion for arrhythmia diagnosis. Its use in a defibrillator should significantly reduce the incidence of inappropriate shocks. Therefore, we evaluated the diagnostic accuracy of an algorithm that uses dual-chamber sensing and analysis of atrioventricular association to discriminate ventricular from supraventricular arrhythmias in a prototype of an implantable defibrillator. METHODS AND RESULTS: The algorithm performed a stepwise analysis of arrhythmias. The rhythm was first classified on the basis of cycle lengths. Each episode was then classified as supraventricular or ventricular in origin on the basis of the stability of cycle lengths and atrioventricular association. This algorithm was evaluated in 156 episodes of induced sustained tachycardias. Eighty-nine tachycardias were taken from the Ann Arbor electrogram library; the others were recorded in 50 patients during electrophysiological studies. The atrial and ventricular signals were stored on an external recorder and then injected into an external prototype of a defibrillator system. The algorithm correctly diagnosed 96% of ventricular tachycardia episodes, 100% of ventricular fibrillation episodes, and 92% of double-tachycardia episodes. The mean detection time for ventricular tachycardia was 2.6 +/- 0.8 seconds, and for ventricular fibrillation, it was 2.1 +/- 0.4 seconds. The positive predictive values for the diagnoses of atrial fibrillation and atrial flutter were 92% and 86%, respectively. For ventricular tachycardia and ventricular fibrillation, the values were 95% and 100%, respectively. CONCLUSIONS: Analysis of atrioventricular association promotes reliable differentiation between ventricular and supraventricular tachycardias and should enhance the diagnostic capabilities of implantable defibrillators.

Algorithms↗
PubMed1997

Automatic external defibrillators for public access defibrillation: recommendations for specifying and reporting arrhythmia analysis algorithm performance, incorporating new waveforms, and enhancing safety. A statement for health professionals from the American Heart Association Task Force on Automatic External Defibrillation, Subcommittee on AED Safety and Efficacy.

These recommendations are presented to enhance the safety and efficacy of AEDs intended for public access. The task force recommends that manufacturers present developmental and validation data on their own devices, emphasizing high sensitivity for shockable rhythms and high specificity for nonshockable rhythms. Alternative defibrillation waveforms may reduce energy requirements, reducing the size and weight of the device. The highest levels of safety for public access defibrillation are needed. Safe and effective use of AEDs that are widely available and easily handled by nonmedical personnel has the potential to dramatically increase survival from cardiac arrest.

Algorithms↗
PubMed1986

Automatic detection of cardiac arrest rhythms prior to automatic external cardiac defibrillation.

The detection and correction of ventricular fibrillation at the earliest time after its onset is essential to ensure long-term survival. During successive cardiac arrests the rhythms occurring were sensed by using disposable pre-gelled ECG defibrillator pads placed in the anterior-anterior position. Simultaneously with the treatment, the arrest rhythms were analyzed continually every 8 to 18 seconds by a microprocessor system. This system sampled digitally the electrocardiogram, and the algorithm looked for absence of the isoelectric segment, irregular energy density spectrum, and irregular wave shape. The analysis was displayed visually as ventricular fibrillation (VF) or non-VF, and simultaneously the ECG and system's analysis were recorded on tape. Later, the system's interpretation of the rhythm was compared with the ECG record. There were 46 males and 32 females. Their ages ranged from 14 to 85 years, with a mean of 63 years. Twenty-nine patients had sustained an acute myocardial infarction. In the remaining 49 patients, there were a variety of causes for cardiac arrest, including heart failure, vasovagal syncope, cardiomyopathy, and postoperative cases. We report in detail the process and results.

Journal Article↗
PubMed1988

[Measurement of arterial pressure by an automatic method. Comparison of various devices for automatic measurement].

A comparative study of three Dinamap 845 instruments was carried out in order to find out whether the use of several automated blood pressure recorders constitutes a major source of variations in epidemiological studies. The three instruments were compared by means of a variant analysis model and proved to have virtually the same accuracy. Only one of them gave a slightly different diastolic pressure reading. No matter how useful are instruments for automated blood pressure measurement, comparisons between several recorders of the same type and regular testing for accuracy seem to be necessary in epidemiological studies.

Analysis of Variance↗