What is the interpretation of this treadmill exercise stress test and the normal ST‑segment values, given the ST levels: pre‑test 0.55 mV, supine 0.48 mV, standing 0.52 mV, hyperventilation 0.55 mV, pre‑exercise wait 0.55 mV, exercise stage 1 0.81 mV, stage 2 0.97 mV, stage 3 0.97 mV, peak exercise 0.64 mV, recovery 1 1.74 mV, recovery 3 1.29 mV?

Interpretation of Treadmill Exercise Stress Test Results

Critical Finding: Abnormal ST-Segment Elevation in Recovery Phase

This treadmill test is strongly positive for myocardial ischemia based on marked ST-segment elevation during recovery (1.74 mV at recovery 1 and 1.29 mV at recovery 3), which far exceeds diagnostic thresholds and suggests significant coronary artery disease requiring urgent further evaluation with stress imaging or coronary angiography. 1

Detailed Analysis of ST-Segment Changes

Baseline and Pre-Exercise Values (Normal Range)

• Your pre-test through hyperventilation ST levels (0.48-0.55 mV) are within normal limits 1
• Normal subjects typically show minimal ST-segment changes at rest, and your baseline values are appropriate 1

Exercise Phase Response

• Stage 1-3 progression (0.81 → 0.97 → 0.97 mV): This represents progressive ST-segment elevation during exercise, which is abnormal 1
• The standard criterion for abnormal ST elevation is ≥0.10 mV (1.0 mm) of J-point elevation persistently elevated at 60 ms after the J point 1
• Your values during exercise stages show elevation approaching 1.0 mV, which is concerning 1

Peak Exercise

• Peak exercise ST level of 0.64 mV shows some normalization, but this does not negate the abnormal elevation seen during exercise stages 1

Recovery Phase (Most Concerning Finding)

• Recovery 1: 1.74 mV - This is severely abnormal and represents marked ST-segment elevation 1
• Recovery 3: 1.29 mV - Persistent elevation well above baseline 1
• After 1 minute of recovery, ST depression attributable to ischemia is generally greater than during exercise in patients with coronary disease, whereas normal subjects show less 1
• The duration of ST abnormalities in the recovery phase is directly related to the severity of coronary artery disease 1

Clinical Significance and Risk Stratification

High-Risk Features Present

• Marked ST-segment elevation >1.0 mV in recovery phase indicates severe transient ischemia, typically from significant proximal coronary disease or spasm 1
• In subjects without prior myocardial infarction, exercise-induced ST elevation frequently localizes the site of severe transient ischemia resulting from significant proximal disease 1
• Values >6 μV/bpm on ST/HR slope calculations are suggestive of anatomically extensive disease, including 3-vessel or left main coronary artery disease 1

Severity Indicators

• The magnitude of ST elevation (1.74 mV) is extremely abnormal and suggests high-risk coronary anatomy 1, 2
• Marked depth of ischemic ST changes aids in identifying patients with severe coronary artery disease and potentially serious prognosis 2
• Patients demonstrating this response have more frequent ventricular arrhythmias during testing 1

Immediate Recommended Actions

Urgent Stress Imaging Required

• You should undergo stress echocardiography or myocardial perfusion imaging immediately to localize the ischemic territory and assess the extent of myocardium at risk 1, 3
• Imaging provides superior diagnostic accuracy compared to ECG changes alone and identifies the location and size of the territory at risk 1
• A reversible perfusion defect will typically correspond to the site of exercise-induced ST elevation 1

Consider Direct Coronary Angiography

• Given the severity of ST elevation in recovery, direct coronary angiography should be strongly considered without intermediate stress imaging, particularly if you have limiting symptoms or recurrent chest pain 3
• High-risk Duke Treadmill Score (≤-11) with these findings warrants consideration for direct angiography 3

Common Pitfalls to Avoid

Do Not Dismiss Recovery Phase Changes

• Recovery phase ST abnormalities are often more diagnostically significant than exercise phase changes and should never be ignored 1
• The persistence of ST elevation well into recovery (still 1.29 mV at recovery 3) indicates sustained ischemia 1

Do Not Delay Further Testing

• These findings represent a high-risk pattern that requires prompt cardiology evaluation within days, not weeks 3, 4
• Patients with this degree of ST elevation during exercise have been reported to have approximately 30% incidence of severe proximal coronary disease or active vasospasm 1

Additional Prognostic Information Needed

• Exercise capacity in METs, heart rate response, blood pressure response, and presence of symptoms during testing are critical for complete risk stratification 1, 3
• Heart rate recovery (difference between peak HR and HR at 1 minute of recovery ≤12 bpm) is an additional high-risk marker 1