A body implantable system employs a lead system having at least one electrode
and
at least one thermal sensor at a distal end. The lead system is implanted within
a patient's heart in a coronary vein of the left ventricle. The thermal sensor
can be attached to a catheter that is disposed within an open lumen of the lead
system. The thermal sensor senses a coronary vein temperature. The coronary vein
temperature can be measured at a detector/energy delivery system and used as an
activity indicator to adaptively control pacing rate. The measured coronary vein
temperature can be also used with a left ventricular flow measurement to determine
hemodynamic efficiency of the heart. A detected change in hemodynamic efficiency
can be used by the detector/energy delivery system to modify the delivery of electrical
pulses to the lead system.
