Exercise and Exercise Stress Testing in Brugada Syndrome

Figures

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  Figure 1. Autonomic Balance During Exercise and Recovery in Brugada Syndrome This schematic illustrates the dynamic interplay between sympathetic and parasympathetic activity during the exercise stress test and highlights the 2 distinct arrhythmogenic windows in Brugada syndrome. During peak exercise, strong sympathetic activation typically attenuates the surface type 1 Brugada pattern (BrP); yet, a subset of patients may develop rate-dependent depolarization delay (eg, S-wave upslope prolongation), which can precipitate ventricular arrhythmias despite the overall J-ST suppression. In contrast, the early recovery phase (first 1-3 minutes) is marked by abrupt sympathetic withdrawal and a surge in parasympathetic tone, leading to accentuated J-ST elevation, increased repolarization heterogeneity, and vulnerability to premature ventricular contractions (PVCs), phase 2 re-entry, and ventricular fibrillation (VF). Together, these mechanisms demonstrate that both peak exertion and early recovery carry arrhythmic potential, driven by distinct electrophysiologic and autonomic factors. The black arrow marks the start of the exercise stress test. The black arrow indicates the start of the exercise…

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  Central Illustration. Autonomic Modulation of Brugada Electrocardiographic Patterns During Exercise and Recovery Exercise stress testing may unmask type 1 Brugada electrocardiographic patterns and provoke arrhythmias during 2 distinct windows: 1) peak exertion, where rate-dependent depolarization delay can reveal conduction vulnerability; and 2) early recovery, where abrupt vagal rebound and repolarization abnormalities can accentuate J-ST elevation and increase arrhythmogenic risk. The illustration highlights these phase-specific mechanisms and summarizes the key diagnostic and prognostic implications of exercise stress testing in Brugada syndrome (BrS). (∗Several case reports have described major arrhythmic events during peak exercise and early recovery). MAE = major arrhythmic events; NSVT = nonsustained ventricular tachycardia; PVC = premature ventricular contraction.

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  Figure 2. Type 1 Brugada Electrocardiographic Pattern Unmasked During Exercise Stress Testing Example of a type 1 Brugada electrocardiographic pattern unmasked during an exercise stress test. A coved-type ST-segment elevation in the right precordial leads emerged and peaked during the early recovery phase. This highlights the value of monitoring the recovery phase to detect concealed Brugada patterns in suspected cases.