Safety backup in arrhythmia discrimination algorithm
AssigneePacesetter, Inc.
InventorsEric S. Fain, Elisabeth Clem, Lisa Malden
Life of this patent
Estimating the term…
Abstract
In an arrhythmia discrimination algorithm a timer is used to trigger the delivery of therapy when no diagnosis is made within a defined time during a tachycardia episode. Where one or more rhythm discriminators or qualifiers such as morphology, sudden onset, interval stability and AV association is enabled, the timer starts as soon as a ventricular interval or interval average is faster than a programmed maximum time to diagnosis (MTD) cutoff. If the timer times out before the algorithm diagnoses a particular rhythm, a programmed therapy is delivered. In the preferred embodiment, the therapy that is triggered is a function of the most recent detected ventricular rate and the programmed MTD therapy.
Claims18
A method for use in a cardiac therapy device for discriminating between a supraventricular tachycardia and a ventricular tachycardia comprising the steps of:
- sensing a cardiac rhythm indicative of cardiac function of a patient's heart;
- detecting a ventricular rate;
- determining if the ventricular rate is within a ventricular tachycardia rate zone;
- starting a timer following detection of a rate in the tachycardia rate zone;
- if the ventricular rate is in the ventricular tachycardia rate zone, applying at least one rhythm qualifier to the sensed cardiac rhythm to diagnose whether the cardiac rhythm is a ventricular tachycardia or a supraventricular tachycardia;
- and
- if a diagnosis of the cardiac rhythm is not determined based on the at least one rhythm qualifier within a predetermined time as measured by the timer, delivering a programmed therapy to the heart.
An arrhythmia discrimination algorithm for analyzing a cardiac rhythm in an implantable cardioverter defibrillator comprising the steps of:
- determining a ventricular rate and an atrial rate for a patient's heart;
- if the ventricular rate falls in a programmed tachycardia rate zone and is greater than the atrial rate by more than a prescribed delta, diagnosing ventricular tachycardia and delivering a programmed therapy;
- if the ventricular rate falls in the programmed tachycardia rate zone and is less than or substantially equal to the atrial rate then further analyzing the rhythm using one or more rhythm qualifiers to diagnose a ventricular tachycardia;
- starting a timer following detection of a rate in the tachycardia rate zone;
- if the ventricular rate is in the tachycardia rate zone, applying at least one rhythm qualifier to the sensed cardiac rhythm to diagnose whether the cardiac rhythm is a ventricular tachycardia or a supraventricular tachycardia;
- and
- if a diagnosis of the cardiac rhythm is not determined based on the at least one rhythm qualifier within a predetermined time as measured by the timer, delivering a programmed therapy to the heart.
Dependencies are inferred from the claim text.