Abstract: A method is provided for use with a human subject. The method includes accessing a cardiac site via a vena cava of the subject, and alleviating heart failure of the subject by applying to the cardiac site, during a refractory period of the site, a refractory-period signal that affects the left ventricle of the subject's heart. Other embodiments are also described.

Abstract: A method of modifying the force of contraction of at least a portion of a heart chamber is provided. A non-excitatory electric field of given duration is applied, at a delay after an activation of the heart, which increase the force of contraction by at least 5%. Apparatus is also provided for pacing with hemodynamic improvement. Circuitry applies an extended pacing signal to electrodes to pace the heart, the extended pacing signal having an overall duration greater than 8 ms from a time of initiation of application of that portion of the signal that initiates action potential propagation. The signal includes a train of biphasic pulses having pulse durations of at least 1 ms, and the signal has an amplitude that is at least three times as great as a threshold for pacing the heart and that is sufficient neither for cardioversion nor for defibrillation. Other embodiments are also described.

Abstract: A cardiac contractility modulating (CCM) device (30) includes an anti-arrhythmic therapy unit (38) for detecting a cardiac arrhythmia in a heart (2) of a patient based on processing electrical signals related to cardiac activity sensed at the heart, and for delivering anti-arrhythmic therapy to the heart. The device includes a cardiac contractility modulating (CCM) unit (40) capable of delivering cardiac contractility modulating (CCM) signals to the heart for modulating the contractility of a portion of the heart. The device (30) includes a power source (165). The device may be an implantable device or a non-implantable device. A method for delivering anti-arrhythmic therapy to a heart. The method includes applying one or more non-excitatory cardiac contractility modulating electrical signals to said heart.

Abstract: A method and apparatus (30) for modifying contractility of the heart of a patient. The method includes receiving signals from a sensor (22, 23, 46) coupled to the body of the patient indicative of physiological activity. The signals are analyzed to derive a measure of the physiological activity, and excitable tissue control (ETC) stimulation is applied to the heart (20) so as to enhance contractility of the heart muscle responsive to the measure.

Abstract: A method and apparatus (30) for modifying contractility of the heart of a patient. The method includes receiving signals from a sensor (22, 23, 46) coupled to the body of the patient indicative of physiological activity. The signals are analyzed to derive a measure of the physiological activity, and excitable tissue control (ETC) stimulation is applied to the heart (20) so as to enhance contractility of the heart muscle responsive to the measure.

Abstract: A method and apparatus (30) for modifying contractility of the heart of a patient. The method includes receiving signals from a sensor (22, 23, 46) coupled to the body of the patient indicative of physiological activity. The signals are analyzed to derive a measure of the physiological activity, and excitable tissue control (ETC) stimulation is applied to the heart (20) so as to enhance contractility of the heart muscle responsive to the measure.

Abstract: Apparatus for applying a non-excitatory signal to a heart, comprising: at least one electrode; a power source; a wide-field ECG sensor that receives a wide-field ECG signal containing contributions from non-local sized portions of the heart; a controller for selectively electrifying said at least one electrode with a non-excitatory signal from said power source; and a safety filter that inhibits said electrifying responsive to said wide-field ECG signal.

Abstract: Apparatus for applying a non-excitatory signal to a heart, comprising: at least one electrode, a power source, a wide-field ECG sensor that receives a wide-field ECG signal containing contributions from non-local sized portions of the heart, a controller for selectively electrifying said at least one electrode with a non-excitatory signal from said power source, and a safety filter that inhibits said electrifying responsive to said wide-field ECG signal.

Abstract: Apparatus and method for determining a mechanical property of an organ or a body part. The method includes positioning an impedance sensor within a blood vessel. The impedance sensor has at least two electrodes disposed within the blood vessel, which is mechanically coupled to the organ or body part. The method further includes determining the electrical impedance between the two electrodes to obtain an impedance signal correlated with the mechanical property of the organ or body part. The organ may be the heart, lungs, uterus, urinary bladder, part of the gastrointestinal tract and the brain. The impedance sensor includes at least two spaced apart electrodes capable of being disposed within a blood vessel. The sensor is operatively connected to an impedance determining unit which determines the impedance between the electrodes. The impedance sensor may be a part of an insertable or implantable lead or catheter like device.

Abstract: A method for automated detection of arrhythmias in a patient is disclosed, said method comprising:

Abstract: A method and apparatus for stimulating cardiac tissue. Pacing pulses are applied to the heart at multiple sites in at least two different chambers of the heart; and an Excitable Tissue Control (ETC) signal is applied in a vicinity of one or more of the pacing sites following application of the pacing pulse at the site.