The ECG was recorded from a 68 year old man who had recently had successful arterial surgery to relieve critical ischaemia in his legs. He had also experienced a transient ischaemic attack in the territory of the right middle cerebral artery five years previously.
The ECG shows the raised ST segments of acute myocardial infarction in leads III and aVF. There is a
pathological Q wave in lead III. There are widespread ST segment changes horizontal ST depression in leads V2, V3 and V4, and downsloping ST depression in leads I and aVL associated with T wave inversion.
The R wave progression in the precordial leads is delayed; The R wave height in leads V2, V3 and V4 is the same in all leads and smaller than expected. The is no R wave of significant size in any of the precordial leads.
The ECG shows evidence of acute inferior infarction with the typical raised ST segments of early infarction and a pathological Q wave. The ST segments in the precordial leads (and the lateral leads I and aVL) show ‘reciprocal changes’. These leads record from the opposite side of the heart to the area affected by the infarcuon and the changes mirror those seen in the leads that record from the infarcted area. The appearances of the ST segments should be carefully studied: The changes in leads V2, V3 and V4 show the horizontal depression often seen in acute ischaemia, leads I and aVL show downsloping ST segments. Compare this ECG with the previous example which showed infarction (and corresponding reciprocal changes) in the opposite ventricular walls to this one. Old anterolateral infarction is also suggested
by the loss of R wave in this ECG. Patients with coronary artery disease often have arterial disease elsewhere. Similarly patients who present with symptoms of cerebrovascular disease or lower limb ischaemia often have coronary artery disease in addition.