An implantable cardiac monitor is arranged for detecting both arrhythmias and ischemia of the human heart. The monitor includes subcutaneous electrodes for establishing electrical contact with the heart and a sense amplifier coupled to each electrode for generating an electrocardiogram of a heart beat sensed at each of the electrodes. The electrocardiograms are digitized and the digital samples thereof are stored in a memory. A microprocessor processes the digital samples of the electrocardiograms and generates characterizing data indicative of the physiology of the heart. The cardiac monitor includes telemetry to permit the cardiac data to be interrogated externally of the patient for obtaining the generated cardiac data indicative of arrhythmic and ischemic episodes.

Implantable cardiac patient monitor

The invention includes systems and methods for converting absolute pressure data acquired in anatomical environments to gauge pressure data using an implant configured to monitor pressure. The implant is configured to communicate with an external controller, which is configured to communicate with a remote microprocessor that includes real-time barometric pressure data for one or more geographic locations.

Barometric pressure correction based on remote sources of information

A method and system for discrimination of supraventricular tachycardia and ventricular tachycardia events. Morphological features points are extracted from normal sinus rhythm (NSR) complexes and used to generate a NSR template. A numerical convolution is performed using the NSR template and the feature points for each sensed NSR to give a NSR filter output. Using a plurality of NSR complexes, a median NSR filter output template is determined, where the median NSR filter output template has a median value for each value in the NSR filter output. The median NSR filter output template is then used during a tachycardia event to distinguish tachycardia events as either ventricular tachycardia events or supraventricular tachycardia events.

Discrimination of supraventricular tachycardia and ventricular tachycardia events

This document describes, among other things, systems, devices, and methods for predicting how the status of the patient's congestive heart failure (CHF) condition will progress in the future. In one example, a therapy is provided or adjusted at least in part in response to the prediction.

Cardiac rhythm management systems and methods predicting congestive heart failure status

An apparatus and method for reversing ventricular remodeling with electro-stimulatory therapy. A ventricle is paced by delivering one or more stimulatory pulses in a manner such that a stressed region of the myocardium is pre-excited relative to other regions in order to subject the stressed region to a lessened preload and afterload during systole. The unloading of the stressed myocardium over time effects reversal of undesirable ventricular remodeling.

Apparatus and method for reversal of myocardial remodeling with electrical stimulation

A cardiac rhythm management system provides for assessment of cardiac mechanical dyssynchrony based on heart sound morphology and optimization of pacing parameters based on the effect of pacing on the cardiac mechanical dyssynchrony assessment. A degree of cardiac mechanical dyssynchrony is measured by the time delay between tricuspid valve closure and mitral valve closure and/or the time delay between pulmonary valve closure and aortic valve closure. A cardiac resynchronization therapy is optimized by determining therapy parameters to provide an approximately minimum degree of cardiac mechanical dyssynchrony by cardiac pacing.

Method and apparatus for optimization of cardiac resynchronization therapy using heart sounds

A cardiac rhythm management system provides a phonocardiographic image indicative of a heart's mechanical events related to hemodynamic performance to allow, among other things, diagnosis of cardiac conditions and evaluation of therapies treating the cardiac conditions. The phonocardiographic image includes a stack of acoustic sensor signal segments representing multiple cardiac cycles. Each acoustic sensor signal segment includes heart sounds indicative of the heart's mechanical events and representations of the heart's electrical events. The diagnosis and/or therapy evaluation are performed by observing or detecting at least an occurrence of a particular heart sound related to a cardiac time interval or a trend of a particular time interval between an electrical event and a mechanical event over the cardiac time interval.

Phonocardiographic image-based atrioventricular delay optimization

A cardiac rhythm management system provides a phonocardiographic image indicative of a heart's mechanical events related to hemodynamic performance. The phonocardiographic image includes a stack of acoustic sensor signal segments representing multiple cardiac cycles. Each acoustic sensor signal segment includes heart sounds indicative of the heart's mechanical events and representations of the heart's electrical events. The stack of acoustic sensor signal segments are aligned by a selected type of the heart's mechanical or electrical events and are grouped by a cardiac timing parameter for presentation.

Method and apparatus for phonocardiographic image acquisition and presentation

A cardiac rhythm management device is configured to detect oscillations in cardiac rhythm by measuring the amplitudes of heart sounds during successive heart beats. Upon detection of acoustic alternans, the device may adjust its operating behavior to compensate for the deleterious effects of the condition.

Method and apparatus for detecting acoustic oscillations in cardiac rhythm

La mesure du debit systolique par un catheter dans le ventricule droit, utilisant i'impedance intracardiaque, au repos et pendant l'exercise peut etre comparee de facon favorable aux mesures obtenues par ventilation a l'acetylene (r = 0.96, n = 13) et par ventriculographie isotopique (r = 0.96, n = 13). Ceci a eteetudie chez un malade de 46 ans en bloc complet. La frequence de stimulation a l'effort a ete determinee par l'impedance en prenant un algorythme qui maintient un debit systolique constant. Le resultat a montre une augmentation du debit cardiaque de 23% et une baisse du debit systolique de 70%, mesuree a l'effort a une frequence de 70 cpm.



Stroke volume measurements made by a catheter-based, right ventricular, intracardiac impedance system at rest and during upright bicycle ergometry were found to compare favorably with measurements made by acetylene rebreathing (r= 0.96, n = 13) and by radionuclide ventricuiography (r= 0.96, n = 13) in a 46-year-old male pacemaker-dependent subject. The impedance information was then used to control the ventricular pacing rate during bicycle exercise, utilizing an algorithm that attempts to maintain a constant stroke volume. This resulted in a 23% increase in cardiac output accompanied by a 70% decrease in stroke volume as compared to the values measured during the same exercise at 70 pulses per minute (ppm).

William C. Lincoln

Papers

Method and apparatus for optimization of cardiac resynchronization therapy using heart sounds

Phonocardiographic image-based atrioventricular delay optimization

Method and apparatus for phonocardiographic image acquisition and presentation

Method and apparatus for detecting acoustic oscillations in cardiac rhythm

Continuous ventricular volume assessment for diagnosis and pacemaker control.