Patent ID: 7736319

Claim:
A device comprising: a heart sound sensor configured to produce a heart sound signal representative of a heart sound, the heart sound associated with mechanical cardiovascular activity of a heart of a subject; and a signal analyzer circuit in electrical communication with the heart sound sensor, wherein the signal analyzer circuit is configured to: establish a baseline value of a time interval between a first detected physiologic cardiovascular event and at least one second detected physiologic cardiovascular event, wherein the first and second detected events occur during a same cardiac cycle, wherein at least one of the first and second detected physiologic cardiovascular events includes a heart sound event detected using the heart sound signal, and wherein the other of the first and second detected physiologic cardiovascular events is associated with a different event; after establishing the baseline, then monitor the time interval over a plurality of cardiac cycles; and determine that an ischemic event occurred using information about how quickly a specified change from the established baseline time interval value occurs during the monitored plurality of cardiac cycles.