Sensing cardiac contractile function

Abstract

Systems and methods for detecting and measuring cardiac contractile function of a heart using an acceleration sensor unit inserted within the heart, such as within a vein of the cardiac wall are disclosed. The systems and methods involve detecting the occurrence of electrical events within the patient's heart by inserting and positioning an implantable lead having an electrode near a cardiac wall as well as detecting mechanical events within the patient's heart by then inserting and positioning a cardiac motion sensor unit through the inner lumen of the implantable lead. Furthermore, the systems and methods do not require dedicated leads and may be used with preexisting implantable leads.

1 . A cardiac apparatus comprising:
 a first lead including an inner lumen, wherein the first lead includes a first conductor configured to sense cardiac electrical activity;   a second lead including a second conductor configured to sense cardiac electrical activity, wherein the first lead is disposed within the second lead; and   a sensing device configured to sense cardiac wall movement, the sensing device disposed within the inner lumen of the first lead.   
   
   
       2 . The cardiac apparatus of  claim 1 , wherein the sensing device includes a cardiac motion sensor including an accelerometer. 
   
   
       3 . The cardiac apparatus of  claim 1 , wherein the first lead is substantially concentrically disposed within the second lead. 
   
   
       4 . The cardiac apparatus of  claim 1 , wherein the sensing device is configured to fit within a vein of the cardiac wall. 
   
   
       5 . The cardiac apparatus of  claim 1 , comprising a connector device configured to connect the sensing device to an electronic device. 
   
   
       6 . The cardiac apparatus of  claim 5 , wherein the electronic device includes an implantable device. 
   
   
       7 . The cardiac apparatus of  claim 5 , wherein the connector device is configured to fix the sensing device relative to the inner lumen. 
   
   
       8 . The cardiac apparatus of  claim 5 , wherein the sensing device includes a cardiac motion sensor coupled to the connector device by an elongate body. 
   
   
       9 . The cardiac apparatus of  claim 8 , wherein the elongate body includes an electrical conductor. 
   
   
       10 . The cardiac apparatus of  claim 1 , wherein the sensing device is removably disposed within the inner lumen. 
   
   
       11 . The cardiac apparatus of  claim 10 , wherein the first lead is configured to remain implanted with the sensing device removed from within the inner lumen. 
   
   
       12 . A cardiac system comprising:
 a first lead including an inner lumen, wherein the first lead includes a first conductor configured to sense cardiac electrical activity;   a second lead including a second conductor configured to sense cardiac electrical activity, wherein the first lead is disposed within the second lead; and   a sensing device configured to sense cardiac wall movement, the sensing device disposed within the inner lumen of the first lead, the sensing device comprising:
 a cardiac motion sensor configured to generate a signal indicative of cardiac wall movement; and 
 a connector device configured to fix the sensing device relative to the inner lumen. 
   
   
   
       13 . The cardiac system of  claim 12 , comprising an electronic device coupled to the connector device of the sensing device, wherein the electronic device is configured to receive from the cardiac motion sensor the signal indicative of cardiac wall movement. 
   
   
       14 . The cardiac system of  claim 13 , wherein the electronic device includes an implantable device. 
   
   
       15 . The cardiac system of  claim 13 , wherein the sensing device is fixed relative to the inner lumen when the connector device is coupled to the electronic device. 
   
   
       16 . The cardiac system of  claim 13 , wherein the sensing device includes an elongate body connecting the cardiac motion sensor to the connector device. 
   
   
       17 . The cardiac system of  claim 16 , wherein the elongate body is configured to transmit the signal indicative of cardiac wall movement from the cardiac motion sensor to the electronic device. 
   
   
       18 . The cardiac system of  claim 12 , wherein the sensing device includes an elongate body connecting the cardiac motion sensor to the connector device. 
   
   
       19 . The cardiac system of  claim 12 , wherein the sensing device is removably disposed within the inner lumen. 
   
   
       20 . The cardiac system of  claim 12 , wherein the first lead is substantially concentrically disposed within the second lead.