US 5,179,949 A · Cardiac pacemaker with automatic A-V programming for optimization of left heart A-V interval

Abstract

A dual-chamber AV sequential pacemaker with the capability of automatically adjusting right heart AV interval to optimize left heart AV interval by compensating for pacing-induced inter-atrial and inter-ventricular conduction delays. Depending on the pacing and sensing action, as determined by the patient's native rate, the predetermined threshold rate and intrinsic AV interval, the pacemaker selects the AV interval. Right heart AV interval is adjusted to compensate for the heart's inter-atrial and inter-ventricular delays. Threshold values are previously estimated, using mean values measured using non-invasive techniques. The pacemaker has a dual phase operating mechanism consisting of an analysis phase followed by a pacing phase. The P wave rate is sensed and compared to a predetermined base rate. If the sensed P wave rate is above the baseline, atrial depolarizations will be sensed by the pacemaker and small number (default=4) of consecutive native AV intervals will be averaged. If this average is less than a predetermined threshold value, the system will continue in the demand mode, sensing P and R waves. If the average is greater than said value, then the ventricle is paced for n number of times the analysis phase (default=100 cycles), each followed by a short AV delay (Default=50 ms) that is intended to compensate for the delay introduced in the onset of left ventricular depolarization after pacing the right ventricular apex. When P wave rate is below the predetermined rate, atrial pacing will occur.

Claims9

Dependent claims

In a cardiac pacemaker of the type including a means for sensing atrial depolarization signals, means for sensing ventricular depolarization signals, control means for receiving said atrial and ventricular depolarization signals, atrial and ventricular pacing means for applying stimulating pulses to the atrium and to the ventricle, said pacemaker further including an improved timing means in said control means comprising:

(a) means coupled to said atrial sensing means for determining whether the rate at which said atrial depolarization signals occur are below a first predetermined value;
(b) AV interval determining mean coupled to said atrial and said ventricular sensing means for determining whether the time between the occurrence of an atrial depolarization signal and the next succeeding ventricular depolarization signal, on the average, exceeds a predetermined AV interval value and if so, triggering said ventricle pacing means to generate a series of ventricular stimulating pulses, each ventricular pulse following a predetermined time delay from the preceding atrial depolarization signal;
and
(c) means for adjusting pacing induced AV interval and for producing an effective left heart AV interval corrected for pacing-induced timing delays which result from whether the artrium and/or ventricles are being paced or sensed.

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Dependencies are inferred from the claim text.

Cardiac pacemaker with automatic A-V programming for optimization of left heart A-V interval

Life of this patent

Cardiac pacemaker with automatic A-V programming for optimization of left heart A-V interval

Life of this patent

Abstract

Claims9