Stress testing with ST-segment depression at rest. An angiographic correlation

Area of Science:

• Cardiology
• Diagnostic Imaging
• Exercise Physiology

Background:

• Patients with chest pain and resting ST depression often require diagnostic evaluation.
• Non-ischemic causes of ST depression must be excluded before stress testing.
• The utility of exercise stress testing in this specific patient group is not fully established.

Purpose of the Study:

• To compare near-maximal graded exercise tests with coronary angiograms in patients experiencing chest pain and resting ST depression.
• To determine the sensitivity and specificity of exercise-induced ST depression for detecting coronary artery obstruction in this population.
• To evaluate the safety and effectiveness of stress testing in selected patients with abnormal resting ECGs.

Main Methods:

• 37 patients with chest pain and resting ST depression (excluding non-ischemic causes) underwent graded exercise testing and coronary angiography.
• Exercise-induced ST depression (≥0.1 mV) was assessed.
• Coronary angiograms were analyzed for the presence and severity of coronary artery obstruction.

Main Results:

• Exercise-induced ST depression occurred in 26 patients, 23 of whom (92% sensitivity) had coronary artery obstruction.
• Eleven patients showed no additional ST depression during exercise; 9 (75% specificity) had normal coronary angiograms.
• Patients with no ST depression increase achieved higher heart rates; those with angina had the least heart rate acceleration.
• Exercise duration correlated inversely with coronary obstruction severity.
• Patients with added ST depression were older (mean 54 years) and predominantly male (18/26).

Conclusions:

• Graded exercise testing is a safe and effective method for diagnosing coronary artery disease in selected patients with resting ST depression.
• The study demonstrates high sensitivity and specificity for exercise-induced ST depression in identifying coronary artery obstruction.
• Stress testing can be safely performed in patients with abnormal resting ECGs, broadening its applicability in clinical practice.