From ST-elevation myocardial infarction to ST elevation with no myocardial infarction—review and overview of a new horizon of computerized electrocardiographic ischemia detection using high-fidelity implantable devices

Single-lead V2 ECG trend of ST-segment level (y axis) versus time (x axis) during a 24-minute period, displaying changes from zero to >1000 μV (10 mm) ST elevation during elective PCI of a left anterior descending artery. Serial balloon inflations are shown as horizontal bars below graph. Digital ST levels (dots) are shown as average ST level in 10-second periods. Sample waveforms corresponding to change in ST levels at times indicated are shown above. Adapted with permission from Krucoff et al [14].

Trend of summated 12-lead ST deviation (y axis) versus time (x axis) during a 4-hour period during elective PCI of proximal left anterior descending artery. Initial series of inflations up to 4 minutes of total occlusion with standard balloon associated with 850 μV of anterolateral ST elevation with reciprocal inferior ST depression (red ECG above). Inflation of a perfusion balloon catheter (PBC), allowing some coronary flow, in identical coronary site for 30 minutes generates diffuse inferolateral ST depression but no ST elevation on 12-lead ECG. Adapted with permission from Krucoff et al [9].

Endocardial EGM from chronic porcine model showing approximately 5 hours after discontinuation of clopidogrel causing copper coronary implant to thrombose with ST elevation, transient reperfusion, and ventricular fibrillation (VFIB). Adapted with permission from Fischell et al [26].

Trend of ST deviation (y axis) versus time (x axis) from wide-area endocardial EGM bipole (tip of catheter in right ventricle to right shoulder implantable device). Simultaneous waveforms from surface ECG lead II and EGM, shown below, trend at baseline (A), during ischemia (B), and recovery (C). Adapted from Theres et al [24].