Assessment of cardiac wall motion using impedance measurements

摘要

In accordance with the techniques for heart monitoring described in this disclosure, an implantable medical device (IMD) may assess cardiac wall motion using impedance measurements through cardiac leads. As an example, the IMD may calculate an amount or rate of change in impedance due to the motion of a wall of the heart during at least a portion of one cardiac cycle, e.g., systole, in order to assess the strength of systolic contraction.

主权项

1. A method comprising:
measuring an impedance of an electrical path that includes a portion of a heart wall a plurality of times during at least one portion of a cardiac cycle, the electrical path comprising a first electrode engaged to or within a wall of a chamber of a heart and a second electrode, wherein the second electrode is an extra-cardiac electrode that is disconnected from the heart; and calculating a value indicative of heart wall motion during the portion of the cardiac cycle based on the impedance measurements.