Patent ID: 8712521

Claim:
A system for monitoring a heart having first and second ventricles, the system comprising: a device including: an impedance measurement circuit, including terminals configured to be coupled to electrodes in association with the first ventricle to measure a first impedance signal that is substantially indicative of a volume of the first ventricle as the first ventricle expands and contracts during a cardiac cycle of the heart and in association with the second ventricle to measure a second impedance signal that is substantially indicative of a volume of the second ventricle as the second ventricle expands and contracts during the cardiac cycle; and a processor, coupled to the impedance measurement circuit to receive information about the first and second impedance signals over the cardiac cycle, the processor configured to perform instructions to detect a first peak of the first impedance signal during the cardiac cycle, detect a second peak of the second impedance signal during the cardiac cycle, determine a first type point on the first impedance signal, the first type point being a function of the first peak, determine a second type point on the second impedance signal, the second type point being a function of the second peak, compute a first slope of the first impedance signal at the first type point on the first impedance signal, compute a second slope of the second impedance signal at the second type point on the second impedance signal, and produce a first resynchronization parameter using a difference between the first slope and the second slope, the first resynchronization parameter indicative of a degree of cardiac mechanical synchrony or asynchrony between the first and second ventricles.