Method and System to Determine Capture Thresholds

A system for automatically determining capture thresholds for an implantable medical device equipped for cardiac stimulus pacing using a multi-pole left ventricular (LV) lead, comprising:

• at least one processor;
• a pulse generator coupled to the multi-pole DI lead;
• and
• a memory coupled to the at least one processor, wherein the memory stores program instructions, wherein the program instructions are executable by the at least one processor to:
• measure a base capture threshold for a base pacing vector utilizing stimulation pulses delivered by the pulse generator varied over at least a portion of an outer capture threshold test range, the base pacing vector defined by a first LV electrode provided on the LV lead and a secondary electrode located remote from an LV chamber;
• designate a secondary pacing vector that includes the first LV electrode and a second LV electrode provided on the LV lead;
• define an inner test range having limits based on the base capture threshold, wherein at least one of the limits for the inner test range differs from a corresponding limit for the outer test range;
• and
• measure a secondary capture threshold associated with the secondary pacing vector utilizing stimulation pulses varied over at least a portion of the inner test range.