Heart treatment equipment and method for preventing fatal arrhythmia

Abstract

In order to avoid a sudden cardiac death by a fatal arrhythmia, various living body information for generating a signal which shows a level of an autonomic tone is detected by a sensor or a VT/VF risk event is detected so as to control the stimulation of the vagus nerve or the nerve stimulation waveform. For this purpose, the parameter of the nerve stimulation signal is controlled according to a detection of the living body information represented by a QT interval which is measured by intracardiac information of the heart or a detection of a VT/VF risk event represented by a ventricular premature contraction which is picked up from spontaneous cardiac events.

1 . A heart treatment equipment comprising: 
 nerve stimulation means for generating a nerve stimulating signal for stimulating a vagus nerve;    sensor means for detecting physical exercise of a patient; and    control means connected to said nerve stimulation means and said sensor means, wherein said control means generates said nerve stimulating signal in response to the detection of said physical exercise such that stronger nerve stimulation is carried out when the value of the physical exercise is large as compared with a situation in which the value of the physical exercise is small.    
   
   
       2 . A heart treatment equipment according to  claim 1 , wherein said control means further comprises a nerve stimulation parameter table memory at which is memorized at least one table relating a plurality of nerve stimulation parameters to sensed values by said sensor means.  
   
   
       3 . A heart treatment equipment according to  claim 2 , wherein said control means controls said nerve stimulation means based on a nerve stimulation parameter selected from the nerve stimulation parameter table memory.  
   
   
       4 . A heart treatment equipment according to  claim 1 , wherein said sensor means detects a ventricle contractility.  
   
   
       5 . A heart treatment equipment according to  claim 4 , wherein the ventricle contractility is related to one of a QT interval, an intracardiac electrogram area, a pre-ejection period, a stroke volume and a ventricle pressure.  
   
   
       6 . A heart treatment equipment according to  claim 4 , wherein said control means controls said nerve stimulation means so as to stop the generation of said nerve stimulating signal when the ventricle contractility is out of a predetermined range.  
   
   
       7 . A heart treatment equipment according to  claim 1 , wherein said sensor means senses a respiration.  
   
   
       8 . A heart treatment equipment according to  claim 1 , wherein said sensor means senses a blood parameter.  
   
   
       9 . A heart treatment equipment according to  claim 1 , wherein said sensor means includes a QT interval sensor.  
   
   
       10 . A heart treatment equipment according to  claim 1 , wherein said sensor means includes a piezoelectric sensor or an acceleration sensor.  
   
   
       11 . A heart treatment equipment comprising: 
 nerve stimulation means for generating a nerve stimulating signal for stimulating a vagus nerve;    sensor means for detecting physical exercise of a patient; and    control means connected to said nerve stimulation means and said sensor means, wherein said control means generates the nerve stimulating signal in response to the detection of the physical exercise.    
   
   
       12 . A heart treatment equipment according to  claim 11 , wherein said control means further comprises a nerve stimulation parameter table memory, wherein said control means controls said nerve stimulation means based on a nerve stimulation parameter selected from the nerve stimulation parameter table memory.  
   
   
       13 . A heart treatment equipment according to  claim 11 , further comprising a heart risk event detector and a ventricle contraction detector, wherein the heart risk event detector determines whether a ventricle risk event exists based upon an output signal from the ventricle contraction detector.  
   
   
       14 . A heart treatment equipment according to  claim 13 , wherein when a risk event is detected by the heart risk event detector, a signal is transmitted to the control means for controlling the nerve stimulating signal according to the detected risk event.  
   
   
       15 . A heart treatment equipment according to  claim 13 , wherein the risk event includes an early afterdepolarization.  
   
   
       16 . A heart treatment equipment according to  claim 13 , wherein the risk event includes a premature contraction.  
   
   
       17 . A heart treatment equipment according to  claim 17 , wherein the sensor means includes a pressure sensor.  
   
   
       18 . A heart treatment equipment according to  claim 11 , wherein the sensor means includes a ventrictility impedence sensor.  
   
   
       19 . A heart treatment equipment according to  claim 18 , wherein the ventrictility impedence sensor includes a pre-ejection sensor.  
   
   
       20 . A heart treatment equipment according to  claim 18 , wherein the ventrictility impedence sensor includes a stroke volume sensor.