Is “silent ischemia” detectable by endocardial pacemaker leads?

The purpose of the following pilot study is to evaluate the possibility to detect the asymptomatic ischemic episodes which often precede dangerous events by means of endocardial signals. Intracardiac electrograms (IEGMs) have been detected in patients undergoing percutaneous transluminal coronary angioplasty (PTCA), a procedure during which ischemic episodes are induced. For 10 patients IECGs have been examined and compared with the surface 12-lead ECGs, used in current clinical practice to make a diagnosis of ischemia. This work takes part in a project (Body Worn) aimed at planning a prompt aid system for patients at high cardiovascular risk implanted with a pacemaker. In case of abnormalities in the endocardial signals detected by pacemaker leads, the intervention procedure is thought to be activated. However, results from primary data show that a diagnosis of silent ischemia cannot be made on the basis of the only IEGMs.