Pharmacological applications in stress testing

Introduction: While exercise remains the preferred method of cardiac stress
testing, pharmacological stress plays an important role in nuclear cardiology.
The globally aging population will see an expansion of the application of
pharmacological stress testing and with that, comes the need to understand
the pharmacologic basis, mechanisms of action, potential interactions and
adverse effects to inform use in less than ideal circumstances. This paper aims
to enhance the decision-making process in day-to-day clinical nuclear cardiology practice informed by the hospital or community pharmacist as a
partnership through a better understanding of nuances relevant to the pharmacological agents employed for cardiac stress testing.

Methods: Pharmacology, nuclear medicine and cardiology reference texts,
and peer reviewed medical journal manuscripts indexed on Medline were
included based on currency, accuracy and appropriateness.

Results: Stress methods are not interchangeable without careful consider-
ation. Coronary artery disease (CAD) is best detected using vasodilator stress
while haemodynamic significance is best assessed using dobutamine or exercise. Caffeine consumption, the use of beta blockers and the role of aminophylline require careful consideration in selecting the approach to stress
testing.

Conclusion: CAD is best detected using vasodilator stress. Adenosine pro-
vides superiority over dipyridamole while regadenoson does not appear to
extend theoretical benefi ts into tangible clinical benefi ts. Haemodynamic
signifi cance is best assessed using dobutamine or exercise. Caffeine ingestion
may not necessitate cancellation or rescheduling of the procedure if an
understanding of pharmacology can be employed to adopt an intuitive
approach to case based decision making.