Method and device for treating cardiac arrhythmias

Abstract

The present invention provides both methods and devices for termination of arrhythmias, such as ventricular or atrial tachyarrhythmias. The device and method involves application of alternating current (AC) for clinically significant durations at selected therapeutic frequencies through the cardiac tissue to a subject experiencing arrhythmia. Methods are also provided to minimize or eliminate pain during defibrillation.

What is claimed is: 
     
         1 . A method of treating cardiac arrhythmia in a subject in need thereof, comprising administering an alternating current (AC) for a clinically significant duration at a selected therapeutic frequency to a cardiac tissue of the subject, wherein the AC is defined by a ramped waveform, thereby treating the cardiac arrhythmia. 
     
     
         2 . The method of  claim 1 , further comprising administering an electronic shock. 
     
     
         3 . The method of  claim 1 , wherein the arrhythmia is tachyarrhythmia. 
     
     
         4 . The method of  claim 3 , wherein the tachyarrhythmia is ventricular tachycardia, ventricular fibrillation, atrial fibrillation, atrial flutter, or atrial tachycardia. 
     
     
         5 . The method of  claim 1 , wherein the AC is administered between a plurality of electrodes. 
     
     
         6 . The method of  claim 5 , wherein the electrodes are positioned intravascularly or intracardiacly on the subject. 
     
     
         7 . The method of  claim 5 , wherein the electrodes are positioned extravascularly or externally on the subject. 
     
     
         8 . The method of  claim 1 , wherein the AC is administered at a frequency between about 50 Hz to 500 Hz. 
     
     
         9 . The method of  claim 1 , wherein the AC is administered at a frequency between about 100 Hz to 200 Hz. 
     
     
         10 . The method of  claim 1 , wherein the AC is administered for a duration between about 0.025 to 5 seconds. 
     
     
         11 . The method of  claim 10 , wherein the AC is administered for at least 0.050 seconds. 
     
     
         12 . The method of  claim 10 , wherein the AC is administered for at least 0.100 seconds. 
     
     
         13 . The method of  claim 1 , wherein the AC inhibits activation of a transmembrane sodium channel of a cell of the cardiac tissue thereby inhibiting fibrillation. 
     
     
         14 . The method of  claim 1 , wherein the method further comprises detecting the occurrence of arrhythmia before or after the AC is administered. 
     
     
         15 . The method of  claim 14 , wherein administration of the AC is synchronously applied with onset of cardiac excitation. 
     
     
         16 . The method of  claim 14 , wherein administration of the alternating current is applied synchronously with cardiac diastole. 
     
     
         17 . The method of  claim 1 , wherein the electronic shock is administered after offset of the AC, or after onset of the AC and before offset of the AC. 
     
     
         17 . The method of  claim 2 , wherein the electronic shock is selected from a monophasic shock, a biphasic shock, or a combination thereof. 
     
     
         18 . The method of  claim 1 , wherein the AC is administered at a first frequency and a second frequency. 
     
     
         19 . The method of  claim 18 , wherein the method further comprises administration of the AC at a third frequency. 
     
     
         20 . The method of  claim 18 , wherein the first and second frequency are different. 
     
     
         21 . The method of  claim 18 , wherein the first and second frequency are the same. 
     
     
         22 . The method of  claim 18 , wherein the AC is administered at a first frequency and a second frequency simultaneously. 
     
     
         23 . The method of  claim 18 , wherein the first and second frequency are applied via different electrodes. 
     
     
         24 . The method of  claim 18 , wherein the first and second frequency are applied via the same electrodes. 
     
     
         25 . The method of  claim 18 , wherein the second frequency is administered in response to detecting that the arrhythmia is not terminated. 
     
     
         26 . A device for treating arrhythmia comprising:
 a computer or microprocessor-readable program containing one or more algorithms for generating or delivering alternating current (AC);   a plurality of electrodes; and   a waveform generator;   wherein the device is configured to generate an alternating current (AC) having a frequency between 50 Hz and 500 Hz, and wherein the AC is defined by a ramped waveform.   
     
     
         27 . The device of  claim 26 , wherein the device is configured to generate AC having a frequency between about 50 Hz to 300 Hz. 
     
     
         28 . The device of  claim 26 , wherein the electrodes are configured for intravascular or intracardiac positioning in a subject. 
     
     
         29 . The device of  claim 26 , wherein the electrodes are configured for extravascular or external positioning on a subject. 
     
     
         30 . The device of  claim 26 , wherein the device further comprises a sensing circuit for determining the presence of arrhythmia. 
     
     
         31 . The device of  claim 30 , wherein the device automatically generates the AC when arrhythmia is detected. 
     
     
         32 . The device of  claim 26 , wherein the device is implantable. 
     
     
         33 . The device of  claim 30 , wherein the device further comprises a programmable logic circuit, such that the device is configured to administer AC after a delay from onset of cardiac excitation. 
     
     
         34 . The device of  claim 26 , wherein the device is further configured to generate and administer an electrical shock. 
     
     
         35 . The device of  claim 34 , wherein the electrical shock is selected from a monophasic shock, biphasic shock, or combination thereof. 
     
     
         36 . The device of  claim 34 , wherein the device is configured to deliver electrical shock and AC via the same electrodes or different electrodes on a same lead. 
     
     
         37 . The device of  claim 31 , wherein the device is configured to deliver AC for tiered therapy, wherein successive AC frequencies are automatically delivered until termination of the arrhythmia is detected. 
     
     
         38 . The device of  claim 37 , wherein each successive AC frequency is different or the same as a previous AC frequency. 
     
     
         39 . A method of inhibiting defibrillation induced pain in muscle tissue of a subject comprising: administering an alternating current (AC) to a targeted site of a heart during an arrhythmia, the AC being defined by a ramped waveform; and administering an electrical shock, thereby inhibiting defibrillation induced pain. 
     
     
         40 . The method of  claim 39 , wherein the AC is administered at a frequency between about 100 Hz to 1 kHz. 
     
     
         41 . The method of  claim 39 , wherein the AC is delivered via a catheter comprising a plurality of electrodes. 
     
     
         42 . The method of  claim 39 , wherein the AC is timed to a surface electrocardiogram or an intracardiac electrocardiogram.