Vitatron Medical B. V.

Medtronic, Inc.

Bernhard De Vries

Malcolm J Begemann

Gustaaf A Stoop

Johannes S Van Der Veen

Hendrik Reineman

Hendrik Van Rooijen

Johannes G Idink

A multi-site atrial pacemaker capable of delivering pacing pulses to one location synchronized to sensed or paced atrial depolarizations on another location and a method of its use. A defined interval is defined following atrial depolarizations during which such synchronized atrial pacing pulses may not be delivered. The pacemaker automatically adjusts the duration of the defined interval to produce a minimum level of induced tachyarrhythmias. Generally, this desired result is accomplished by measuring coupling intervals of PACs, monitoring occurrences of atrial tachyarrhythmias associated with PACs and adjusting the defined interval accordingly.

Method and apparatus for prevention of atrial tachyarrhythmias

The invention provides an implantable medical device system and method for determining when a patient is undergoing a sudden rate drop (SRD) that should be treated by intervention therapy. Two SRD detection algorithms are provided. A first algorithm is a rate-based algorithm that looks for rate drops that meet stored SRD criteria, and a second algorithm is a QT-based algorithm that detects when QT variations meet criteria that are associated with rate changes characteristic of onset of NMS. The system provides for a plurality of different intervention pacing therapies that are selected based on which detection algorithm, or both algorithms, indicate SRD. The priority of choice of algorithms is programmable.

Pacemaker with sudden rate drop detection based on QT variations

There is provided a cardiac pacemaker system with a ventricular tachycardia prevention feature, whereby the pacemaker monitors ventricular activity during each patient awakening period to determine when VT is likely. In a preferred embodiment, QRS and T wave templates are generated cyclically during awakening, and compared to normal templates to obtain a measure of variability, indicative of refractory dispersion and thus of probable VT. Ventricular extra-systoles are also monitored and analyzed during the awakening period to see how closely they occur to the ventricular vulnerable period. When the monitored data indicates VT probability during awakening, the pacemaker responds by overdriving the heart with an intervention pacing rate which is continually adjusted as a function of the currently obtained data.

Pacemaker system with diurnal pattern controlled overdrive for

There is provided a pacemaker system with an SRD detection and intervention feature, which enables a simple way of initiating confirmation of SRD, i.e., looking for an AS/AP transition in a DDD or DDI pacemaker, or a transition from a VS to a VP in a DDI pacemaker. This simple initiation of SRD confirmation is made possible by use of a relatively wide hysteresis band which is normally operative when a spontaneous rate is present, and which tracks physiological changes in the patient's natural rate, across the pacemaker rate range. Transitions which result from a gradual decrease in natural rate and thus represent physiological bradycardia are not interpreted as suggesting SRD. The detection is confirmed only after a predetermined number of pace pulses are delivered at the hysteresis rate, i.e., 1-5 pulses. In a preferred embodiment, after confirmation of SRD, pacing starts at a programmable intervention rate, and rate flywheels downward toward a lower rate limit, with intermittent hysteresis scans at a lower rate to enable recovery of an underlying natural rate. The SRD mode is left whenever recovery of a natural rate is confirmed, as by sensing a predetermined number of consecutive natural atrial beats in DDD mode or atrial and/or ventricular beats in DDI mode.

Pacing system with full range sudden rate drop detection and responsive

A pacemaker system is provided for rate responsive pacing, wherein rate is controlled as a function of two or more sensor inputs, each sensor providing a signal representing a respective different control parameter. Preferably a first sensor signal represents a physiologically accurate although slow response signal such as OT interval, and a second sensor represents a relatively fast response such as activity. The two parameter signals are processed so that they are directly comparable and can be compared as indicators of pacing rate throughout the desired pacing range. The algorithm utilizes a parameter control reference curve for each respective parameter, such reference curve representing the desired correlation between pacing rate and the parameter signal. Rate control is accomplished by determining the difference between each processed parameter signal and its corresponding reference point for the current pacing interval, and logically analyzing the two differences to determine which is used to indicate change in pacing rate. Each parameter reference curve is automatically adjustable to correspond to patient conditions. Automatic drift correction of the fast response parameter, such as activity, is used to compensate for conditions where the fast response signal is not likely to be physiologically reflective of the patient condition.

Growing community of inventors

Dieren, Netherlands

Bernhard De Vries