Potential of an intracardiac electrogram for the rapid detection of coronary artery occlusion
Tim A Fischell1, David R Fischell, Robert E Fischell
1Borgess Heart Institute, Kalamazoo, MI 49048, USA. taf1@net-link.net
Background:
Early identification of acute MI and prompt intervention can improve clinical outcomes. It would be valuable to identify a method that could allow the earliest possible detection of myocardial injury or ischemia.
Methods And Results:
This article reports one of the first clinical investigations to examine the ability of an intracardiac right ventricular (RV) electrode to identify the early onset of myocardial ischemia/injury in a cohort of patients undergoing balloon occlusion of a coronary artery during percutaneous transluminal coronary angioplasty. The primary data set for analysis included observations from 14 patients with 17 lesions, with a matched comparison of a V6 surface lead and the RV to left upper chest, "intracardiac" lead. The intracardiac lead was sensitive in detecting myocardial injury current/ischemia. There was a 36.4+/-5.6% ST-segment shift, relative to the amplitude of the QRS complex, in the intracardiac lead at 2 min, compared with a 10.1+/-1.9% ST shift from a surface lead (P=.00011). The RV to left upper chest lead detected a >10% shift in ST segment within 2 min in 17 (100%) of 17 cases vs. 8 (47%) of 17 for a V6 surface lead. The intracardiac lead provided detection of ischemia in all three major epicardial coronary distributions.
Conclusions:
This study demonstrates the ability of an intracardiac (RV apex to left upper chest) lead to rapidly detect myocardial ischemia/injury during acute coronary occlusion in the setting of balloon angioplasty. The results of this study suggest that a simple implantable system resembling a ventricular pacemaker could be programmed to assist in the very early diagnosis of acute myocardial infarction.
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