Method of using electrical energy to produce temporary conduction block for defibrillation and cardioversion

Abstract

A method for treating arrhythmias which includes the steps of detecting an arrhythmia, and, in response to detection of the arrhythmia, delivering electrical energy to a targeted part of myocardial tissue in such a manner as to create a transient conduction block in the targeted part of the myocardial tissue without causing permanent damage to the targeted part of the myocardial tissue. The electrical energy can be continuous or pulsed RF, or continuous or pulsed DC. The detected arrhythmia can be atrial fibrillation, atrial flutter, ventricular fibrillation, or other type of arrhythmia. The targeted part of the myocardial tissue constitutes a critical part of the reentrant pathway or reentrant circuit required to sustain the detected arrhythmia. The electrical energy is preferably delivered via a catheter-based electrode which is in direct contact with the targeted part of the myocardial tissue, for either a prescribed period of time or until the arrhythmia is no longer detected (i.e., is terminated). In the former case, the prescribed period of time can be either sufficient to ensure that the arrhythmia can no longer be sustained, or sufficient to ensure that the arrhythmia is organized well enough to be terminated with additional low energy cardioversion/defibrillation therapy (such as a biphasic shock or pulse train). In a first alternative embodiment of the method of the present invention, a shock (or other form of cardioversion or defibrillation therapy) can be delivered, and then, if necessary (e.g., if it is detected that the fibrillation has not been terminated), electrical energy can be delivered to a targeted part of the myocardial tissue in order to create a transient conduction block in the targeted part of the myocardial tissue. In a second alternative embodiment of the method of the present invention, electrical energy is delivered to a targeted part of the myocardial tissue in order to create a first transient conduction block in the targeted part of the myocardial tissue, then a shock (or other form of cardioversion or defibrillation therapy) can be delivered, and then, if necessary (e.g., if it is detected that the fibrillation has not been terminated), electrical energy can again be delivered to the targeted part of the myocardial tissue in order to create a second transient conduction block in the targeted part of the myocardial tissue. The method is preferably carried out by using an automatic implantable defibrillator.