ECG ischemia simulator
Pick an occlusion site or an ECG pattern and see the artery, the infarcted segments, the 12-lead ECG and the perfusion map together; then watch the ECG evolve from hyperacute T waves to Q waves, with or without reperfusion.
For learning. The heart, the ECG and the perfusion maps are schematic models built from published segment, territory and lead rules; they are not patient data and do not feed the other tools. Real coronary anatomy varies, and every pattern here has mimics.
Lesion
Left anterior descending (LAD)
Left circumflex (LCx)
Right coronary artery (RCA)
Heart and coronary tree
perfused myocardiuminfarcted segmentsarteryoccluded, no flow
The whole LAD territory: anterior wall, anterior septum and apex, including the basal segments supplied by S1 and D1.
Segments: 1 basal anterior, 2 basal anteroseptal, 7 mid anterior, 8 mid anteroseptal, 13 apical anterior, 14 apical septal, 17 apex.
Perfusion imaging (stress and rest)
Fixed defect: reduced uptake in segments 1, 2, 7, 8, 13, 14, 17 at stress and at rest, the signature of infarcted (or hibernating) myocardium.
12-lead ECG, fully developed ST elevation
ST depressionST elevation25 mm/s, 10 mm/mV; schematic, not a real tracing.
ST elevation in V1 to V4 with elevation in aVL and aVR and reciprocal depression in II, III and aVF: occlusion before the first septal and diagonal branches.
ST elevation meeting the 5th UDMI threshold in aVL, V1, V2, V3, V4, V5; reciprocal ST depression in II, III, aVF.
Teaching points
- An occlusion proximal to the first septal and first diagonal branches produces ST elevation in V1 to V4 and in aVL, with reciprocal ST depression in the inferior leads; ST elevation in aVR and a new right bundle branch block point to a proximal site.
- The infarct includes the basal anterior and anteroseptal segments, which D1 and S1 would have spared. Proximal LAD occlusion carries the largest territory of any single vessel after the left main.
- An occluded artery with infarction leaves a fixed perfusion defect: reduced uptake at stress and at rest in the same segments.
About the model
- The left ventricle is divided into 17 segments (6 basal, 6 mid, 4 apical and the apex) for every imaging method, and each segment is assigned to a coronary territory by convention. The simulator paints those segments.
- The assignment is an approximation. On contrast cardiac MRI the inferior and lateral segments are supplied by different arteries in different people, depending on dominance and branch size, so the segments marked variable here can belong to a neighbouring territory.
- Leads facing the injured wall show ST elevation; leads facing the opposite wall show the mirror image, reciprocal ST depression. The limb leads are drawn from one frontal injury vector, which is why II always equals I plus III here.
The heart model is drawn from the AHA segment angles, not from an anatomical scan; vessel courses are the usual ones. The ECGs are generated from lead rules and are schematic. Further reading: the AHA segmentation statement .