Exercise-Induced Left Bundle Branch Block in a Patient With Syncope: A Case Report.

Area of Science:

• Cardiology
• Electrophysiology

Background:

• Exercise-induced left bundle branch block (EI-LBBB) is uncommon, especially in individuals without structural heart disease.
• The underlying pathophysiology of EI-LBBB is not well understood, and established treatment guidelines are lacking.

Purpose of the Study:

• To present a case of EI-LBBB in a patient with minimal coronary artery disease.
• To discuss the evaluation and management of EI-LBBB, including the role of exercise training.

Main Methods:

• Case report of a 77-year-old male experiencing syncope and EI-LBBB during a cardiac stress test.
• Diagnostic workup included coronary angiography and comprehensive cardiac evaluation.
• Management involved initiating an aerobic exercise program.

Main Results:

• The patient exhibited transient electrocardiographic changes consistent with EI-LBBB during stress testing, which resolved at rest.
• Coronary angiography showed only mild-moderate stenosis in the proximal left anterior descending artery.
• The patient reported symptomatic improvement following the commencement of an aerobic exercise program.

Conclusions:

• EI-LBBB can manifest in patients with normal cardiac structure and minimal coronary artery disease.
• Aerobic exercise training may be a viable management option for selected EI-LBBB patients.
• Further research is needed to elucidate EI-LBBB pathophysiology and establish treatment protocols.