Telectronics Pacing Systems, Inc.

Anthony J Murphy

David Bassin

David Mason

Anthony C Stephens

Saul E Greenhut

John P Wickham

Richard Saumarez

A cardiac implant device is provided in which the ventricular rate is monitored to differentiate between atrial fibrillation and ventricular tachycardia or other cardiac conditions. For this purpose, the ventricular rate stability is monitored by, for example, measuring the R-R intervals of successive ventricular beats. If the ventricular rate is found to be unstable, the ventricle is paced at a test rate to try to stabilize the ventricle. If the attempt is unsuccessful, atrial fibrillation is assumed and, if necessary, corresponding therapy is applied. If the attempt is unsuccessful, atrial fibrillation is eliminated as a cause of the ventricular rate instability and other types of classifying and treating the cardiac condition may be used.

Apparatus and method for detection of atrial fibrillation by ventricular

A method, useable in implantable cardioverter defibrillators, for classifying heart rhythms of a patient by means of electrogram morphology. A number of features (metrics) of the electrogram are measured to form a description of the shape of individual electrograms, and the metrics are then converted into a cardiac rhythm diagnosis by means of a pattern classification technique.

Method of classifying heart rhythms by analyzing several morphology

An implantable dual chamber ICD and method senses atrial (A-A) and ventricular (V-V) intervals, calculates the ratio (A/V interval ratio) of A-A intervals to V-V intervals, classifies heart rhythms with V-V intervals (i) above a revert rate threshold as not tachycardia, (ii) below a high rate threshold as treatable tachycardia, (iii) between the two thresholds and below an A-dominant A/V interval ratio threshold as a non-treatable tachycardia, (iv) between the revert rate threshold and the high rate threshold and above a V-dominant threshold as treatable tachycardia and, when the heart rhythm is intermediate all four thresholds, (v) utilizes one or a combination of advanced discriminators (e.g., ventricular windowing, ventricular interval variability, sudden onset, AV-delay creep, ventricular electrogram morphology, active sensing, minute ventilation, or right ventricular pressure) to classify whether the heart rhythm is a non-treatable or a treatable tachycardia.

Heart rhythm classification method, and implantable dual chamber

An apparatus and a method for discriminating between tachycardias of physiological origin, and those of pathological origin having similar atrial and ventricular rates, are disclosed. The apparatus includes two sensing electrodes for registering the electrograms from the atrium and the ventricle of the heart. There is further included a signal processing element for determining the times of atrial and ventricular events, and an algorithm for classifying the heart rhythm. The algorithm includes a means for discriminating between different types of heart rhythms having overlapping ventricular rates and having similar atrial and ventricular rates. The method utilizes an analysis of the relationships between successive atrial and ventricular intervals (i.e., atrial-atrial (AA), ventricular-ventricular (VV) and atrial-ventricular (AV) intervals) in discriminating between such heart rhythms.

Apparatus and method for discriminating between associated and

Apparatus and method for discriminating between heart rhythms with

A method and apparatus for detecting and reverting pathological heart rhythms of a patient are disclosed. A plurality of electrical heart rhythm signals of the patient are sensed at two different locations within the heart. The cross-phase spectra of the sensed heart rhythm signals for each heartbeat are calculated and such heart rhythms are classified based upon the information contained in the cross-phase spectra. Appropriate therapy is then delivered to the patient's heart to revert those of the heart rhythms that are classified as pathological.

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Annandale, Australia

Anthony J Murphy