Myocardial perfusion scintigraphy is to evaluate coronary perfusion as well as heart muscle function. This examination takes place in two stages, one imaging at rest and one after a cardiac stress caused. This stress can be triggered as a first-line stress test. A pharmacological stress is proposed when stress test is not possible or contraindicated, Several drugs have a marketing authorization in this indication (adenosine, dipyridamole, regadenoson, dobutamine).

Among them, the regadenoson is the most recent molecule. Marketed in France since 2013, it would allow a reduction of undesirable effects compared to other agents, especially adenosine. It is simple and quick to use thanks to a single dose administration. However, its cost is nearly 30 times higher than dipyridamole. In the investigational center, dipyridamole is currently the first-line pharmacological stress agent, whereas regadenoson is reserved for a limited number of doses, the indication of which must be justified (asthmatic patient or with severe COPD). Few studies in the literature specifically compare these two pharmacological agents (examination time, cost, tolerance) and the opinion on the use of regadenoson in the service is limited.

Inclusion Criteria:

• Adult ≥ 18 years
• Myocardial scintigraphy by pharmacological stress agent
• Used molecules = Dipyridamole or Regadenoson

Exclusion Criteria:

• Physical stress test by single or mixed effort (associating pharmacological stress)
• Pharmacological agent used = Adenosine
• Inclusion in the ERCAD protocol
• Double isotope protocol
• Patient refusal due to study information

Patients reffered for an indication of myocardial perfusion scintigraphy in the nuclear medicine unit