Dipyridamole-echocardiography test in patients with exercise-induced ST-segment elevation

Area of Science:

• Cardiology
• Diagnostic Imaging
• Clinical Electrophysiology

Background:

• Exercise-induced ST-segment elevation suggests myocardial ischemia.
• Dipyridamole is used pharmacologically to induce ischemia for diagnostic purposes.
• Understanding the diagnostic accuracy of dipyridamole testing is crucial.

Purpose of the Study:

• To evaluate the dipyridamole test's ability to induce and detect myocardial ischemia.
• To correlate electrocardiographic (ECG) changes with echocardiographic findings during dipyridamole infusion.
• To assess the predictive value of dipyridamole-induced ST-segment elevation for significant coronary artery disease.

Main Methods:

• Fourteen patients with exercise-induced ST-segment elevation underwent dipyridamole infusion.
• Continuous 12-lead electrocardiographic (ECG) monitoring was performed.
• Two-dimensional echocardiography assessed left ventricular regional wall motion during the test.

Main Results:

• Dipyridamole induced ST-segment elevation in 7 patients, consistently correlating with reversible regional asynergy on echocardiography.
• In patients with dipyridamole-induced ST-segment elevation, angiography invariably showed severe coronary artery stenosis.
• Dipyridamole-induced ST-segment depression was associated with reversible asynergy in 2 patients, also linked to coronary stenosis.

Conclusions:

• Dipyridamole can induce transmural ischemia, evidenced by ST-segment elevation on ECG.
• ST-segment elevation during dipyridamole testing reliably predicts the presence and location of transient regional myocardial dysfunction.
• This ECG pattern strongly indicates severe coronary artery stenosis in the affected myocardial region.