Abstract: A cardiac monitoring system for monitoring a plurality of patients including a plurality of patient-worn units and one or more office units. A patient unit detects a patient's EKG and analyzes the EKG in real time (during the patient's R-R interval). It provides morphology analysis, heart rate data, ST segment analysis, symptomatic and asymptomatic event recordings, and the counting of ectopic runs. The analyzed data is sent over a standard voice-grade telephone line or other suitable communication channel to an office which prepares a patient report for a physician. In addition, the office unit provides an interactive scheme by which various alarm and recording criteria are established for a particular patient at the time of hook-up. Also, the office unit automatically communicates with the physician under predetermined emergency circumstances so that a patient can get medical attention with a minimun time delay.

Abstract: A device for automatically indicating a rate failure condition in a pacer monitoring the intrinsic pacer rate in both demand and fixed rate modes, including a first limit circuit preset at a low level of activity coupled to the monitoring means, and a second limit circuit preset at a high level of activity coupled to the monitoring means. A first switch is connected to the first limit circuit, and a second switch is connected to the second limit circuit. The first limit circuit responds to the combined rate of pacer and spontaneous activity falling below a preset level by placing the first switch in a switched condition, and the second limit circuit responds to the rate of pacer activity exceeding a preset level by placing the second switch means in a switched condition. Indicating means converts the switched conditions to distinguishable marking pulse signal for later clinical electrocardiogram detection.

Abstract: A pacer for cardiac pacing and condition monitoring in which the electrical characteristics of the pacer are altered upon a temporary or permanent charge in monitored conditions, such as the failures defined in a "loss of capture" or a "failure to sense", in which the timed relationship between the pacer signal generator and the cardiac signal is monitored to indicate detection of failure condition. The monitor acts to provide both increased stimulus to recover capture and to provide warning pulses indicating loss of capture or failure to sense, which are sufficiently discernible upon an electrocardiogram to enable later diagnosis, even after self-correction. An additional means for improving the ability of the pacemaker to "pick up" and amplify spontaneous cardiac signals is provided by redundant signal amplifiers which are checked against each other. These circuits and their ability to detect improper recycling are used to indicate a "sensing failure".

Abstract: A pacer for cardiac pacing and condition monitoring in which the electrical characteristics of the pacer are altered upon a temporary or permanent change in monitored conditions, such as the failures defined as a "loss of capture" or a "failure to sense", in which the timed relationship between the pacer signal generator and the cardiac signal is monitored to indicate detection of failure condition. The monitor acts to provide both increased stimulus to recover capture and to provide warning pulses indicating loss of capture or failure to sense, which are sufficiently discernible upon an electrocardiogram to enable later diagnosis, even after self-correction. After diagnosis, the monitor can be reset to its original condition by means of an external control, such as a magnet. The unit may be surgically implanted or employed externally.

Abstract: A pacer for cardiac pacing and condition monitoring in which the electrical characteristics of the pacer are altered upon a temporary or permanent change in monitored conditions, such as the failures defined as a "loss of capture" or a "failure to sense", in which the timed relationship between the pacer signal generator and the cardiac signal is monitored to indicate detection of failure condition. The monitor acts to provide both increased stimulus to recover capture and to provide warning pulses indicating loss of capture or failure to sense, which are sufficiently discernible upon an electrocardiogram to enable later diagnosis, even after self-correction. After diagnosis, the monitor can be reset to its original condition by means of an external control, such as a magnet. The unit may be surgically implanted or employed externally.

Abstract: A pacer for cardiac pacing and condition monitoring wherein the electrical characteristics of the pacer are altered upon a temporary or permanent change in monitored conditions, such as loss of capture or failure to sense. The monitor acts to provide both increased stimulus to recover capture and to provide warning pulses indicating loss of capture or failure to sense, which are sufficiently discernible upon an electrocardiogram to enable later diagnosis, even after self-correction. After diagnosis, the monitor can be reset to its original condition by means of an external control, such as a magnet. The unit may be surgically implanted or employed externally.

Abstract: Described is method and apparatus for transmission of electrocardiography (EKG) signal wave trains from a patient's location via common carrier wire lines, such as telephone lines, to a central diagnostic office. The EKG signals consist of a composite train of Pacemaker potentials (artifacts) derived from an implanted Pacemaker, and of potentials derived from the heart itself. At the central, the EKG signals are pen-recorded, but additionally a train of Pacemaker artifacts only, is formed and from it is determined the Pacemaker frequency as an indication of remaining Pacemaker battery life. The central is provided with additional equipment, such as an arrhythmia analyzer which prepares an interval histogram from the patient's EKG signal. The histogram serves as an indication of "loss of capture" of the patient's heartbeat by the Pacemaker and such loss of capture is confirmed by the absence of correlation between the Pacemaker artifact and the "QRS complex" portion of the patient's EKG.