The pretest ECG of a treadmill exercise test series shows a bit of artefacts especially in leads II and III. The pretest heart rate is about 100/min, possibly due to apprehension.
ECG recording in stage 1 of the Bruce protocol of treadmill exercise test. The heart rate has increased and there are not many artefacts and no significant ST segment shift is evident.
The recording at the peak exercise shows significant horizontal ST segment depression in inferior and lateral leads at a fast heart rate. But the significant level of artefacts in the raw rhythm strip make us suspect whether the ST segment depression could be artifactual due to computerized averaging in the computer synthesized rhythm.
The recording in early phase of recovery at 1 minute shows very little ST segment depression, making us suspect further whether the earlier recording was really due to myocardial ischemia. But the ST segment is downsloping in inferior leads.
ECG at 3 minutes of recovery shows further worsening of ST segment depression in inferior and lateral leads, establishing the presence of significant myocardial ischemia.
TMT recovery phase ECG at 6 minutes showing the persistence of downsloping ST segment depression. This calls for further evaluation including coronary angiography and revascularization if feasible. Moreover, ECG recording has to be continued till the ST segment shift resolves.