Supranormal heart rate during peak exercise stress test triggering type-1 Brugada ECG pattern

Area of Science:

• Cardiology
• Electrophysiology
• Exercise Physiology

Background:

• Brugada syndrome (BrS) is a genetic disorder characterized by specific electrocardiogram (ECG) abnormalities and an increased risk of sudden cardiac death.
• The type-1 ECG pattern in BrS, a coved ST-segment elevation, is often intermittent and can be unmasked by various provocative stimuli.
• Maximal exercise testing is a standard diagnostic tool in cardiology but its role in unmasking BrS has been less extensively studied.

Observation:

• A 52-year-old patient with a known diagnosis of Brugada syndrome underwent a maximal capacity exercise test.
• During the exercise test, as the patient's sinus heart rate reached supranormal levels, the diagnostic type-1 ECG pattern of BrS manifested.
• This characteristic BrS pattern was transient, appearing only at peak exercise and disappearing immediately after exercise cessation.

Findings:

• Maximal exercise, leading to a supranormal heart rate, served as a potent provocative factor for unmasking the type-1 Brugada syndrome ECG pattern.
• The dynamic nature of the type-1 BrS pattern was clearly demonstrated, appearing with physiological stress and resolving with recovery.
• This observation underscores the influence of heart rate and autonomic changes during exercise on the manifestation of BrS.

Implications:

• Maximal exercise testing can be a valuable tool for diagnosing Brugada syndrome, particularly in cases with intermittent or non-diagnostic baseline ECGs.
• Understanding the provocative effects of exercise on BrS may inform risk stratification and management strategies for affected individuals.
• Further research into the electrophysiological mechanisms underlying exercise-induced BrS pattern changes could enhance our understanding of the syndrome's pathophysiology.