Stress Test-Induced Left Bundle Branch Block

Area of Science:

• Cardiology
• Nuclear Medicine
• Diagnostic Imaging

Background:

• Myocardial perfusion imaging (MPI) is crucial for diagnosing coronary artery disease.
• Regadenoson, a selective A2A adenosine receptor agonist, is commonly used as a vasodilator in MPI.
• Complications of Regadenoson use, though rare, require careful consideration.

Observation:

• Left bundle branch block (LBBB) is an infrequent complication observed during Regadenoson-induced stress MPI.
• The precise mechanism linking Regadenoson and LBBB development is not fully elucidated.
• Potential mechanisms may involve ongoing myocardial ischemia during the stress test.

Findings:

• The occurrence of LBBB following Regadenoson administration in MPI is uncommon.
• This specific complication might serve as a potential indicator of significant coronary artery disease.
• LBBB during Regadenoson MPI could also suggest pre-existing cardiac conduction abnormalities.

Implications:

• Physicians must be aware of LBBB as a possible complication of Regadenoson MPI.
• Recognizing this event can aid in the accurate diagnosis of coronary artery disease.
• Understanding this association is vital for appropriate risk stratification of patients undergoing MPI.