Abstract: An anti-reentry apparatus and method for reverting ventricular arrhythmias. Biphasic stimulation is applied at multiple ventricular sites to revert arrhythmias caused by reentry, particularly multiple random reentry. In the preferred embodiment, the first phase of biphasic stimulation is anodal, and is at a maximum subthreshold amplitude. The anodal phase preconditions the myocardium to accept the second phase (cathodal) such that less electrical energy is required to reach the threshold amplitude to produce depolarization. The anodal phase stimulation may have a shape over time that is square wave, ramped, or a series of short square wave pulses. Multiple electrodes located at multiple ventricular sites may be stimulated simultaneously, or they may be sequentially stimulated over time in a manner mimicking the normal progress pattern of cardiac depolarization. The multiple ventricular electrodes may stimulate from internal or external surfaces.

Abstract: Augmentation of electrical conduction and contractility by biphasic stimulation of muscle tissue. A first stimulation phase has a first phase polarity, amplitude, and duration. The first stimulation phase, which acts as a conditioning mechanism, is administered at no more than a maximum subthreshold amplitude. A second stimulation phase has a second polarity, amplitude, and duration. The two phases are applied sequentially. Contrary to current thought, anodal stimulation is applied as the first stimulation phase, followed by cathodal stimulation as the second stimulation phase. In this fashion, pulse conduction through muscle is improved, together with an increase in contractibility. Furthermore, this mode of biphasic stimulation reduces the electrical energy required to elicit contraction. In addition, the conditioning first stimulation phase decreases the stimulation threshold by reducing the amount of electrical current required for the second stimulation phase to elicit contraction.

Abstract: Augmentation of electrical conduction and contractility by biphasic cardiac pacing. A first stimulation phase is administered to the cardiac blood pool. This first stimulation phase has a predefined polarity, amplitude and duration. A second stimulation phase is then administered to the cardiac blood pool. This second phase also has a predefined polarity, amplitude and duration. The two phases are applied sequentially. Contrary to current thought, anodal stimulation is first applied and followed by cathodal stimulation. In this fashion, pulse conduction through the cardiac muscle is improved together with the increase in contractility.

Abstract: Atrial sensing and stimulation as intervention for atrial fibrillation. The present invention relates to a method of atrial defibrillation using an implanted electronic stimulator. In a variety of protocols varying combinations of conventional and biphasic stimulation are applied at threshold and sub-threshold levels. In a preferred embodiment, the implantable electronic stimulator of the present invention includes multiple electrodes having stimulating and sensing capabilities. The small size of these electrodes allows for intravenous insertion into the patient.

Abstract: Augmentation of electrical conduction and contractility by biphasic cardiac pacing. A first stimulation phase is administered to the muscle tissue. This first stimulation phase has a predefined polarity, amplitude and duration. A second stimulation phase is then administered to the muscle tissue. This second phase also has a predefined polarity, amplitude and duration. The two phases are applied sequentially. Contrary to current thought, anodal stimulation is first applied and followed by cathodal stimulation. In this fashion, pulse conduction through the cardiac muscle is improved together with the increase in contractility. The technique can also be applied to large muscle tissue stimulation other than cardiac muscle.