Abstract: Ventricular arrhythmias are monitored and classified based upon various criteria. One criterion is PR dissociation which is determined by comparing the PR interval in a current RR cycle to a median PR value. If the current PR interval varies too far from the median, then dissociation is indicated. Often, there are multiple atrial events in a given RR interval and the PR value has been based upon the last atrial event in the cycle. An algorithm determines whether to use the last atrial event in a cycle or whether an earlier atrial event occurred and would provide a more accurate PR value.

Abstract: Techniques are provided for tracking patient respiration based upon intracardiac electrogram (IEGM) signals or other electrical cardiac signals. Briefly, respiration patterns are detected based upon cycle-to-cycle changes in morphological features associated with individual electrical events with the IEGM signals. For example, slight changes in the peak amplitudes of QRS-complexes, P-waves or T-waves are tracked to identify cyclical variations representative of patient respiration. Alternatively, the integrals of the morphological features of the individual events may be calculated for use in tracking respiration. In any case, once respiration patterns have been identified, episodes of abnormal respiration, such as apnea, hyperpnea, nocturnal asthma, or the like, may be detected and therapy automatically delivered. In particular, techniques for detecting abnormal respiration based on various respiratory parameters derived from the IEGM—such as respiration depth and respiration power—are described.

Abstract: The present disclosure includes a system and method of detecting LQTS in a patient by comparing a collected set of ECG data from the patient to a plurality of databases of collected ECG data. The plurality of databases will include a database containing previous ECGs from the patient, a known acquired LQTS characteristics database, and a known genetic LQTS characteristics database. Comparing the patients ECG to these databases will facilitate the detection of such occurrences as changes in QT interval from success of ECGs, changes in T-wave morphology, changes in U-wave morphology and can match known genetic patterns of LQTS. The system and method is sensitive to patient gender and ethnicity, as these factors have been shown to effect LQTS, and is furthermore capable of matching a QT duration to a database of drug effects. The system and method is also easily integrated into current ECG management systems and storage devices.

Abstract: A method differentiating LQT1 mutation from LQT2 mutation is disclosed. An ECG signal is obtained for a patient. At least a first ECG parameter and a second ECG parameter are determined from the ECG signal. A probability that the patient is an LQT1 carrier or an LQT2 carrier is determined based on a regression model which takes into account the first ECG parameter and the second ECG parameter. A system for assessing repolarization abnormalities is also disclosed. The system has a processor configured to differentiate between LQT1 and LQT2 based on at least two ECG parameters from ECG data. The system also has a data input coupled to the processor and configured to provide the processor with the ECG data. The system further has a user interface coupled to either the processor or the data input.

Abstract: An implantable cardiac stimulation device includes a system that identifies and prevents the occurrence of impending atrial arrhythmias. A sensing circuit senses atrial activity of a patient's heart to provide an atrial activity signal. A processor compares the atrial activity signal to a predetermined standard indicative of an impending accelerated atrial arrhythmia to identify an impending accelerated atrial arrhythmia. A therapy circuit provides accelerated atrial arrhythmic preventive therapy to the patient when an impending accelerated atrial arrhythmia is identified. Data associated with the identification and therapy delivery is stored in a memory.

Abstract: A device and method for delivering electrical stimulation to the heart in a manner which provides a protective effect against subsequent ischemia is disclosed. The protective effect is produced by configuring a cardiac pacing device to intermittently switch from a normal operating mode to a stress augmentation mode in which the spatial pattern of depolarization is varied to thereby subject a particular region or regions of the ventricular myocardium to increased mechanical stress.

Abstract: A medical device programmer or other external system capable of programming an implantable CRM device includes a wide-QRS detection and alerting system. Upon detection of a wide QRS complex, a wide-QRS indicator produces a visual indication of the detection using one or more presentation devices such as a display screen and a printer to alert a physician or other caregiver.

Abstract: In general, the invention is directed to an apparatus and method for determining whether an identified atrial tachyarrhythmia episode has terminated. The invention enables determination of whether the tachyarrhythmia episode has terminated based on cardiac beat pattern. In some embodiments of the invention, the determination as to whether the episode has terminated is made irrespective of the rate of atrial depolarizations.

Abstract: A cardiac rhythm management device is configured to detect oscillations in cardiac rhythm by comparing electrogram signals during successive heart beats. Upon detection of electrical alternans, the device may adjust its operating behavior to compensate for the deleterious effects of the condition.

Abstract: An implantable ischemia detecting devices generates a plurality of electrograms for analysis. A processor integrates the ST segment and T wave of each electrogram and normalizes the resulting integral by a normalizing factor to provide a ST segment score and T wave score, respectively. The ST segment and T wave scores are then utilized to compute a total ST segment and T wave score for analysis in detecting or monitoring ischemia of a patient's heart.

Abstract: A technique is provided for detecting episodes of cardiac ischemia based on an examination of the total energy of T-waves. Since cardiac ischemia is often a precursor to acute myocardial infarction (AMI) or ventricular fibrillation (VF), the technique thereby provides a method for predicting the possible onset of AMI or VF. Briefly, the technique integrates internal electrical cardiac signals occurring during T-waves and then compares the result against a running average. If the result exceeds the average by some predetermined amount, ischemia is thereby detected and a warning signal is provided to the patient. The maximum slope of the T-wave is also exploited. Techniques are also set forth herein for reliably detecting T-waves, which help prevent P-waves from being misinterpreted as T-waves on unipolar sensing channels. The T-wave detection technique may be used in conjunction with ischemia detection or for other purposes.

Abstract: Receiving an action potential signal associated with a myocardial contraction sensed at a myocardial site, receiving an action potential signal associated with the myocardial contraction sensed at a different myocardial site, comparing a common characteristics of each of the action potential signals wherein the common characteristics relates to at least one member selected from the group consisting of depolarization of tissue at the myocardial sites and repolarization of tissue at the myocardial sites, and, based on the comparing, deciding whether to call for anti-arrhythmia therapy.

Abstract: A device for the analysis of the alternans cycle to cycle and/or the variability of the ventricular repolarization wave in an ECG signal. This device extracts from an ECG signal, for each cardiac beat, a temporal segment of T samples of the ventricular repolarization wave, considered as from a moment t following a predetermined temporal origin. The T samples for B consecutive beats are aggregated and a local variance factor is evaluated. The square root of the local variance is obtained and weighted by a factor of local alternans. The device delivers at the output an index of alternans and variability TVarb function, for a given beat, local variance factor weighted by the factor of local alternans.

Abstract: A template selection method involves providing a plurality of templates representing a type of cardiac event. One or more characteristics of each template are evaluated. The evaluations are compared and a template is selected as a current template based on the comparison.

Abstract: A cardiac rhythm management system measures a time interval between a first fiducial marker indicative of a ventricular depolarization (e.g., a Q-wave, an R-wave, etc.) and a second fiducial marker indicative of a subsequent mitral valve closure (MVC) occurring during the same cardiac cycle. Such time intervals are used for detecting atrioventricular (AV) dissociation. The AV dissociation may, in turn, be used for discriminating between a supraventricular tachyarrhythmia (SVT) and a ventricular tachyarrhythmia (VT) or for any other diagnostic or therapeutic purpose. The AV dissociation and/or SVT/VT discrimination information may be communicated from an implantable cardiac rhythm management device to an external interface and/or used to determine the nature of therapy delivered to the subject. In a further example, amplitudes indicative of the MVCs are also used for determining whether AV dissociation exists.

Abstract: Methods and apparatus for determining T-wave alternan signatures (i.e., morphology and polarity) derived from a physiologic signal representative of a subject's heart activity; assessing changes in the myocardium Action Potential (“AP”) through analysis of the alternan signature derived from a physiologic signal representative of a subject's heart activity; and/or assessing spatial disassociation of alternan characteristics that are likely associated with the initiation of re-entrant arrhythmias.

Abstract: A method implemented in a dual chamber cardiac rhythm management device for identifying non-sinus ventricular depolarizations following an atrial event. The PR interval for a sensed ventricular beat that occurs after either an atrial pace or an atrial sensed event is examined and if it falls into a non-physiologic range, it is classified as an ectopic beat. If the PR interval is close to a physiologic range, the RR to AA ratio and a PR interval for the current beat are compared to those for an immediately preceding beat. Attention is also paid to the morphology of the ventricular depolarization in determining whether a beat is ectopic or not.

Abstract: A method of assessing the cardiac arrhythmia risk in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. In one embodiment, the method comprises the steps of: (a) collecting at least one QT and RR interval data set from the subject; (b) separating fluctuations from slow trends in said at least one QT and RR interval data set; (c) comparing said QT and RR fluctuations to one another and (d) generating from the comparison of step (c) partial measures of risk of cardiac arrhythmia in said subject. A greater difference between QT and RR fluctuations indicates greater risk of cardiac arrhythmia in said subject. The data sets are collected in such a manner that they reflect almost exclusively the conduction in the heart muscle and minimize the effect on the data sets of rapid transients due to autonomic nervous system and hormonal control.

Abstract: A cardiac arrhythmia monitor provides electrodes to allow daily ECG measurements of a patient without cumbersome electrode connection to the patient. ECG data may be diagnosed by the monitor to indicate likelihood of an arrhythmia and an indication provided to the patient ECG data based on that indication may be forwarded to a physician or other healthcare professional for a review.

Abstract: Systems and methods that improving the specificity of discriminating between a monomorphic tachyarrhythmia and a polymorphic tachyarrhythmia are provided that examine frequency content and baseline information of the EGM as discriminatory signatures. Particular algorithms of the present invention that are employed to determine frequency content of the QRS complexes are titled the Slope Distribution Metric (SDM) algorithm and the Slope Distribution Composite (SDC) algorithm.

Abstract: An implantable cardiac device and method provides for monitoring a progression or regression in heart disease during an extended time period. A sensor generates an electrogram signal representing electrical activity of a patient's heart. From the generated electrogram signal, a processor determines morphology measurements wherein the morphology measurements indicate a progression or regression in the heart disease. The morphology measurements are stored in a memory during the extended period of time. A telemetry circuit transmits the stored morphology measurements to an external receiver for retrieval or display. The morphology measurements may be of electrogram intrinsic activity or evoked response activity characteristics.

Abstract: Methods, systems, and computer program products can be provided for evaluating a risk of the occurrence of cardiac arrhythmias in a heart. The system can include at least one sensing electrode and a controller. The sensing electrode can be configured to sense electrical signals from a heart over a range of heart rates. The controller can be configured to determine values of a at least one restitution property of the heart from the sensed electrical signals and to evaluate the risk of the occurrence of cardiac arrhythmias from the determine values of the at least one restitution property.

Abstract: An arteriosclerosis detection system including an electrocardiographic signal detection device, an eyeground image detection device for detecting an eyeground image in synchronization with an electrocardiographic signal detected by the detection device. The arteriosclerosis detection system further includes an eyeground vein constriction detection device for detecting the constriction of an eyeground vein in the vicinity of a site at which the eyeground vein and an eyeground artery cross each other. The constriction is detected based on the detected eyeground image in synchronization with the electrocardiographic signal. The arteriosclerosis detection system detects the eyeground image by executing an algorithm of software, which provides an eyeground image synchronized with an electrocardiographic signal by obtaining a stationary eyeground image synchronized with an arbitrary electrocardiographic signal from an animated eyeground image.

Abstract: Device for representing the time profile of a structural variation, in particular of the course of a disease with the aid of 2D or 3D data records, by a segmenting device in which time interval data records in the region of the structural variations are differently colored and subsequently matched with the aid of anatomical landmarks.

Abstract: A system and method for determining a reference baseline record for use in automated patient care. One or more physiological measures are retrieved. Each of the measures relates to individual patient information recorded during an initial observation period from a patient care record. One or more reference measures are determined from the physiological measures. Each reference measure is representative of at least one of measured and derived patient information. The reference measures are stored into the patient care record indicating a reference baseline patient status.

Abstract: Nonlinear-dynamical control, also known as chaos control, can modulate human cardiac electrophysiological dynamics by stabilizing an unstable target rhythm. Intracardiac, repolarization alternans detection methods are disclosed that operates on the basis of amplitude or repolarization duration detection. Also disclosed are control methods for stabilizing repolarization alternans.

Abstract: A system and method for detecting a patient's susceptibility to arrhythmias and cardiac tissue abnormality is disclosed. The method consists of using a computer 27, a display 23, software loaded onto the computer that generates graphical user interfaces (GUIs), an electronic interface 18, and a plurality of electrodes. The electronics interface 18 is in electronic communication with the computer 27, and further in electronic communication with the electrodes that are placed by self-adhesion at predetermined locations on a test subject 35. According to one aspect of the invention, the method enables a user, typically a medical professional, to initiate, with minimal input, certain diagnostic tests involving observing and analyzing a series of QRS complexes 130, some of which are biased with a subpacing current, and others of which are unbiased. The signals are then compared, and the differences are analyzed to detect a patient's susceptibility to arrhythmias and cardiac tissue abnormality.

Abstract: A system and method for statistically analyzing QT interval as a function of changes in the RR interval. The system and method utilize three statistical comparisons to fully characterize the QT response: (1) the comparison of curves to give an overall effect; (2) the incidence of points exceeding a baseline upper 95% single-point prediction bound to reflect the degree of heterogeneity of ventricular repolarization; and (3) the magnitude of these points to provide a quantitative assessment of treatment-induced changes in the QT-RR relationship. The system and method use the relationship between the QT interval and heart rate (RR interval) to reference a control baseline response. Data from mammals such as humans and dogs, and pharmacological maneuvers using both cardiac and non-cardiac therapeutic agents, may be used with this multi-parameter statistical system and method.

Abstract: An implantable medical device includes a sensor and a T-wave analyzer. The sensor is implantable within the body of a patient to sense electrical cardiac activity and provide an indication of T-wave alternans within the heart of the patient. The T-wave analyzer is responsive to the sensor, and evaluates cardiac risk based on comparison of the indication of T-wave alternans to a predetermined criterion. The T-wave analyzer may form part of a microprocessor, a digital signal processor, or combination of both. The device may include a pacing generator that applies increased rate pacing stimuli to the heart to facilitate sensing of the T-wave alternans by the sensor. The device also may incorporate a memory that stores the T-wave alternans indication provided by the sensor, e.g., over a number of heartbeats. In addition, the device may be equipped to provide an alert to the patient or a physician in the event the processor generates the indication of cardiac risk.

Abstract: Bi-Ventricular or AV synchronous cardiac pacing systems that pace and sense in at least one atrial heart chamber and deliver ventricular pacing pulses to right ventricular (RV) and left ventricular (LV) sites separated by a V—V delay for treatment of heart failure are disclosed that optimize one or more of the AV delay and V—V delay to enhance left ventricular filling and cardiac output as a function of QRS duration. A system and method for monitoring the QRS duration, processing such signals to provide data from which the onset or progression of heart failure is determined, and adjusting synchronous pacing delay parameters including SAV delay and/or PAV delay and/or V—V delay to enhance cardiac output as a function of QRS duration is provided. The SAV, PAV, and/or the V—V delays can be varied from the prevailing delays as a function of measured QRS duration so as to minimize the width of the QRS complex.

Abstract: A biomagnetic field measuring apparatus has a plurality of fluxmeters disposed externally of a living body and each including a superconducting quantum interference device (SQUID) for detecting a biomagnetic field generated from the living body, the plurality of fluxmeters being operative to detect a temporal change of a component of the biomagnetic field in a first direction which is vertical to the surface of the living body, an operation processor for performing computation for determining a temporal change of a value proportional to a root of square sum of differential value of the first-direction magnetic field component in second and third directions which cross the first direction and computation for integrating the temporal change of the value over a predetermined interval to determine an integral value, and a display for displaying the determined integral value. Distribution of magnetic fields generated from the heart is determined with a small number of fluxmeters.

Abstract: Alternans is measured in a physiological signal, such as an electrocardiogram, by processing the physiological signal to create a processed signal having an asymmetric spectrum, and processing the processed signal to measure alternans in the physiologic signal. The physiological signal may be processed to produce an analytical signal by converting the signal to the frequency domain, removing components corresponding to negative frequencies, and converting back to the time domain.

Abstract: A system and method classify cardiac complexes based on cardiac information derived from two or more cardiac signals. Two or more cardiac signals containing cardiac complexes are monitored. A cardiac complex in the two or more cardiac signals is isolated in an analysis window. The morphology of the cardiac complex in each of the two or more cardiac signals is then compared to the morphology of a template cardiac complex representing a predetermined cardiac condition. Based on this comparison, the cardiac complex is classified as either belonging or not belonging to the predetermined cardiac condition.

Abstract: Detecting atrial and ventricular tachyarrhythmias involves classifying atrial interval rates in an atrial window having a first length and ventricular interval rates in a ventricular window having a second length. The second length of the ventricular window differs from the first length of the atrial window to enhance detection of ventricular arrhythmias relative to atrial arrhythmia detection. The atrial and ventricular interval rates in the respective windows are classified as fast or acceptable with respect to predefined thresholds. A ventricular episode is declared in response to satisfying the ventricular window according to a second satisfaction criterion. An atrial episode is declared in response to satisfying the atrial window according to a first satisfaction criterion.

Abstract: An implantable medical device system for regulating a heart of a patient. The system includes a first sensor, a second sensor, a processor, and a medical device. The first sensor is capable of sensing activity of a heart atrium. The second sensor is capable of sensing activity of a heart ventricle. The processor is coupled to the first and second sensors and is capable of determining an atrial cycle time and a ventricular cycle time based upon signals from the first and second sensors. The processor is further capable of generating a hemodynamic baseline ratio based upon an atrial cycle time and a ventricular cycle time of a hemodynamic heartbeat, as well as an active ratio based upon an atrial cycle time and a ventricular cycle time of an active heartbeat. The processor is further capable of comparing the hemodynamic baseline ratio and the active ratio, and determining a corrective action based upon this comparison.

Abstract: A quantitative method and apparatus for measuring a cardiac function interval. Beat-to-beat data representative of a cardiac interval is collected over an extended period of time. A series of bins, each of which has a defined value range, is defined. The collected data is organized into the bins in accordance with the value of the data and the value range of the bin. The percentage of data in each bin may be calculated based upon the quantity of data in each bin.

Abstract: A method for storing from a temporal sequence of a plurality of individual cardiac events cardiac rhythm information comprised of at least one determined type, in particular a sequence of time intervals between ventricular and/or atrial events, whereby a time interval continuum of the temporal distances between the events is subdivided into time portions of a predetermined length, which are each allocated a single-valuedd marker, in particular a number, each time interval detected with a detection of the cardiac rhythm as one recording is provided with the marker of the time portion into which it falls, the number of the recordings out of a predetermined total number of detected time intervals or belonging to each marker during a predetermined period of time, is assessed, and the markers which have been allocated from a predetermined number of time intervals or during a predetermined period of time at least one recording, each are stored along with the number of recordings.

Abstract: An electrocardiogram processing technique for measuring T-wave alternans by which the alternating electrocardiogram signals are aligned to a target cubic spline. The target cubic spline is calculated on base of three isoelectric points namely a point before the P-wave, a point before the QRS-complex and a point after the T-wave. The aligned signals may then be further analyzed for variations such as T-wave alternans which are only present in alternating beats and which have diagnostic significance.

Abstract: A biomagnetic field measuring apparatus has a plurality of fluxmeters disposed externally of a living body and each including a superconducting quantum interference device (SQUID) for detecting a biomagnetic field generated from the living body, the plurality of fluxmeters being operative to detect a temporal change of a component of the biomagnetic field in a first direction which is vertical to the surface of the living body, an operation processor for performing computation for determining a temporal change of a value proportional to a root of square sum of differential value of the first-direction magnetic field component in second and third directions which cross the first direction and computation for integrating the temporal change of the value over a predetermined interval to determine an integral value, and a display for displaying the determined integral value. Distribution of magnetic fields generated from the heart is determined with a small number of fluxmeters.

Abstract: A method of diagnosing pathologic heart conditions in which a time series of heart sounds is filtered and parsed into a sequence of individual heart cycles. A systolic interval as well as systolic sub-intervals are identified for each heart cycle. An energy value is computed for the systolic sub-interval of one or more heart cycles. The energy value computed is proportional to the energy level associated with the filtered series of heart sounds. A composite energy value is then computed for the systolic sub-intervals of one or more heart cycles and compared to a threshold level in order to distinguish between a normal heart and a pathologic heart. The system corresponding to the method is comprised of a portable computing device that manages data collection and stores data collected from new patients, and analyzes data.

Abstract: The invention is drawn to detect arteriosclerosis by convenient and sensitive means. The present inventors have found that such means can be obtained by use of an arteriosclerosis detection system including electrocardiographic signal detection means, eyeground image detection means for detecting an eyeground image in synchronization with an electrocardiographic signal detected by the detection means, and eyeground vein constriction detection means for detecting the constriction of an eyeground vein in the vicinity of a site at which the eyeground vein and an eyeground artery cross each other, on the basis of the eyeground image detected in synchronization with the electrocardiographic signal.

Abstract: A device and a process for analyzing a medical condition of a user. This device and process can also be used to predict a future abnormal medical condition of the user. The device includes a portable information-receiving device, an information processing device and a remote storage and processing device. These three devices may be in communication with each other via a wireless communication system. This device can include a GPS system for locating the user when the user is having an abnormal medical condition. The process is designed to take a digital signal from a plurality of ECG sensors on the portable information device and form a QRS wave. One or more points are extracted from this QRS wave are used to form a QRS complex wave. QRS complex waves are used to analyze the medical condition of the user. A plurality of parameters are calculated from these points on the QRS wave. If the medical condition of the user is in an abnormal range then an alarm will sound.

Abstract: A method for monitoring the progression of the hemodynamic status of a heart failure patient. An implantable or other ambulatory monitor senses the patient's electrocardiogram (ECG) and calculates R-R intervals. The R-R intervals are used to calculate a measure of heart rate variability (HRV). Significant excursions from the average of the HRV measure are indicative of a heart failure exacerbation. Alternatively, vascular plethysmography provides a measure of pulse amplitude. Significant reduction in pulse amplitude and pulse amplitude variability are indicative of a heart failure exacerbation. This information may be used to warn the patient or healthcare providers of changes in the patient's condition warranting attention.

Abstract: A method and system nodal rhythm detection and treatment is provided. Detecting consecutive atrial events within a nodal activity window around ventricular events identifies nodal rhythm. Nodal rhythm is treated by calculating and applying a new atrial escape interval adjusted by the interval between the atrial and ventricular events.

Abstract: A method of accurately determining if ectopic beats are occurring in the heart by detecting the time interval, T, between a point Q* defined is the onset of the QRS complex and the peak value of R (T=Q*R) during a heart beat cycle and comparing that time with a running mean value calculated from normal heartbeats. A beat is identified as an ectopic beat if the Q*R time interval for a current beat is at least four standard deviations from the mean Q*R time interval of normal preceding beats. The electrodes for detecting the ectopic beats may be inside the patient's heart or on the patient's skin. If more than one electrode is used for monitoring the depolarization of the heart, then by combining the Q*R intervals (e.g. using a triangulation method) calculated from different electrodes, the location of the ectopic excitation can be determined and identified.

Abstract: A method of operating an implantable medical device is provided. A plurality of atrio-ventricular (AV) measurement signals is received. A QT interval is determined. The QT interval is a function of the AV measurement signals. Each of the plurality of AV measurement signals is compared with the QT interval. Finally, if one of the plurality of AV measurement signals is less than the QT interval, a difference between the one of the plurality of AV measurement signals and the QT interval is stored.

Abstract: A system and method classify cardiac complexes based on cardiac information derived from two or more cardiac signals. Two or more cardiac signals containing cardiac complexes are monitored. A cardiac complex in the two or more cardiac signals is isolated in an analysis window. The morphology of the cardiac complex in each of the two or more cardiac signals is then compared to the morphology of a template cardiac complex representing a predetermined cardiac condition. Based on this comparison, the cardiac complex is classified as either belonging or not belonging to the predetermined cardiac condition.

Abstract: A quantitative method and apparatus for measuring a cardiac function interval. Beat-to-beat data representative of a cardiac interval is collected over an extended period of time. A series of bins, each of which has a defined value range, is defined. The collected data is organized into the bins in accordance with the value of the data and the value range of the bin. The percentage of data in each bin may be calculated based upon the quantity of data in each bin.

Abstract: A method for determining the baroreflex provides a non-invasive measurement of cardiac-interval periods, and a mathematical analysis of these measurement values on the basis of non-linear dynamic methods.

Abstract: A system and method for statistically analyzing QT interval as a function of changes in the RR interval. The system and method utilize three statistical comparisons to fully characterize the QT response: (1) the comparison of curves to give an overall effect; (2) the incidence of points exceeding a baseline upper 95% single-point prediction bound to reflect the degree of heterogeneity of ventricular repolarization; and (3) the magnitude of these points to provide a quantitative assessment of treatment-induced changes in the QT-RR relationship. The system and method use the relationship between the QT interval and heart rate (RR interval) to reference a control baseline response. Data from mammals such as humans and dogs, and pharmacological maneuvers using both cardiac and non-cardiac therapeutic agents, may be used with this multi-parameter statistical system and method.