Efficient delivery of multi-site pacing

Abstract

An implantable device and associated method for delivering multi-site pacing therapy is disclosed. The device comprises a set of electrodes including a first ventricular electrode and a second ventricular electrode, spatially separated from one another and all coupled to an implantable pulse generator. The device comprises a processor configured for selecting a first cathode and a first anode from the set of electrodes to form a first pacing vector at a first pacing site along a heart chamber and selecting a second cathode and a second anode from the set of electrodes to form a second pacing vector at a second pacing site along the same heart chamber. The pulse generator is configured to deliver first pacing pulses to the first pacing vector and delivering second pacing pulses to the second pacing vector. The pulse generator generates a recharging current for recharging a first coupling capacitor over a first recharge time period in response to the first pacing pulses. The pulse generator for generating a recharging current for recharging a second coupling capacitor over a second recharge time period in response to the second pacing pulses. An order of recharging the first and second coupling capacitors is dependent upon one of ventricular pacing mode, left ventricle to right ventricle delay (V-V) pace delay, multiple point LV delay and latest delivered pacing pulses to one of the first and second pacing vectors.

1 .- 58 . (canceled) 
     
     
         59 . A method for adjusting multisite pacing to effectively capture tissue by an implantable medical device, the method comprising:
 selecting a first cathode and a first anode to form a first pacing vector;   selecting a second cathode and a second anode to form a second pacing vector;   simultaneously or sequentially delivering a first pacing pulse to the first pacing vector positioned at a first pacing site along a heart chamber and a second pacing pulse to the second pacing vector positioned at a second pacing site along a heart chamber within a single cardiac cycle;   determining whether the first and second pacing pulses are effectively capturing at the first and second pacing sites; and   in response to determining ineffective capture, selecting a first action to achieve effective capture for the first and second pacing pulses being delivered simultaneously and selecting a second action if the first and second pacing pulses being delivered sequentially.   
     
     
         60 . The method of  claim 59  wherein the first action includes increasing energy delivered to cardiac tissue. 
     
     
         61 . The method of  claim 59  further comprising determining whether energy delivered via the first pacing pulses or the second pacing pulses is at a highest output. 
     
     
         62 . The method of  claim 59  wherein further comprising:
 determining whether highest pacing output is being generated by the implantable medical device at one of the first and second pacing sites; 
 in response to determining the highest pacing output is not being generated, increasing the pacing output. 
 
     
     
         63 . The method of  claim 59  wherein further comprising:
 determining whether highest pacing output is being generated by the implantable medical device at one of the first and second pacing sites, in response to determining the highest pacing output is being generated; 
 determining ineffective capture is present at one of the first and second pacing sites. 
 
     
     
         64 . The method of  claim 59  wherein determining ineffective capture is occurring in response to determining the first pacing pulses or the second pacing pulses is at a highest output. 
     
     
         65 . The method of  claim 59  wherein the second action includes shortening inter-electrode timing. 
     
     
         66 . The method of any of  claims 59  through  65  wherein the implantable medical device includes a multiple electrode medical lead extending from the implantable medical device. 
     
     
         67 . The method of  claim 66  wherein the lead comprises a first electrode, a second electrode, third electrode and fourth electrode. 
     
     
         68 . An implantable medical device comprising:
 a sensing module configured to sense cardiac signals;   a signal generator configured to generate and deliver electrical ventricular stimulation pulses (Vp) through a medical electrical lead that includes a first electrode spatially separated from a second electrode;   a processor coupled to the sensing module and the signal generator and configured to:
 (a) control the stimulation generator to deliver a first Vp to a first tissue site and a second Vp to a second tissue site within a single cardiac cycle; 
 (b) determine from the sensed cardiac signals whether the first and second Vp are effectively capturing at the first and at the second pacing sites; and 
 (c) in response to a failure to effectively capture, selecting a first action to achieve effective capture if the first and second pacing pulses were delivered simultaneously and selecting a second action if the first and second pacing pulses were delivered sequentially. 
   
     
     
         69 . The implantable medical device of  claim 68  wherein the first action comprises shortening interelectrode timing. 
     
     
         70 . The implantable medical device of  claim 68  wherein the second action comprises increasing pacing output delivered to one of the first and second tissue sites. 
     
     
         71 . A method for determining effective capture of a multisite pacing therapy, the method comprising:
 selecting a first cathode and a first anode to form a first pacing vector;   selecting a second cathode and a second anode to form a second pacing vector;   delivering a first pacing pulse to the first pacing vector positioned at a first pacing site along a heart chamber;   delivering sequentially a second pacing pulse to the second pacing vector positioned at a second pacing site along a heart chamber within a single cardiac cycle;   determining whether the first and the second pacing vectors effectively capture cardiac tissue; and   shorten inter-electrode timing for delivery of pacing pulses.