What is the clinical evidence from this study?

Study design: Case-Control. Population: Brugada syndrome (n=8). Intervention: Brugada syndrome vs. Control patients. Primary outcome: Monophasic action potentials (MAPs) from epicardial sites of the right ventricular outflow tract.

What question did this study set out to answer?

The study aims to elucidate the electrophysiologic mechanisms leading to ST-segment changes in Brugada syndrome.

August 5, 2026Journal of the American College of Cardiology178 citationsOpen Access

The electrophysiologic mechanism of ST-segment elevation in Brugada syndrome

TKTakashi Kurita WSWataru Shimizu MIMasashi Inagaki

Key Result

A spike-and-dome configuration was documented from epicardial sites of the right ventricular outflow tract in all 3 Brugada patients but not in 5 control patients.

Key Points

The study aims to elucidate the electrophysiologic mechanisms leading to ST-segment changes in Brugada syndrome.
Monophasic action potentials were recorded from 3 Brugada patients and 5 control patients during open-chest surgery.
Epicardial and endocardial action potential recordings focused on the right ventricular outflow tract.
A spike-and-dome configuration was observed in all Brugada patients' epicardial recordings, but not in controls.
No morphological abnormalities were found in endocardial recordings from Brugada patients.

Study Design

Type

Case-Control (n=8)

Structured PICO

What is the electrophysiologic mechanism underlying ST-segment elevation in Brugada syndrome?

Population

8 patients (3 with Brugada syndrome and 5 controls) undergoing open-chest surgery.

Exposure

Epicardial and endocardial monophasic action potential (MAP) recordings using the contact electrode method during open-chest surgery.

Comparator

Control patients without Brugada syndrome.

Outcome

Morphological characteristics of monophasic action potentials (MAPs) in the right ventricular outflow tract.surrogate

This study provides direct in vivo evidence that a transmural voltage gradient caused by a prominent epicardial action potential notch (spike-and-dome) in the right ventricular outflow tract underlies the characteristic ST-segment elevation in Brugada syndrome.

Abstract

OBJECTIVES: We sought to demonstrate the electrophysiologic (EP) mechanism of the ST-T change in Brugada syndrome. BACKGROUND: Brugada syndrome is characterized by various electrocardiographic manifestations (e.g., right bundle branch block, ST-segment elevation, and terminal T-wave inversion in the right precordial leads) and sudden cardiac death caused by ventricular fibrillation. Direct evidence in support of the EP mechanism underlying this intriguing syndrome has been lacking. METHODS: Monophasic action potentials (MAPs) were obtained from three patients with the coved-type ST-segment elevation (Brugada patients) and five control patients using the contact electrode method. Epicardial MAPs were recorded during open-chest surgery in all patients. RESULTS: A spike-and-dome configuration was documented from epicardial sites of the right ventricular (RV) outflow tract in all Brugada patients but not in control patients. Monophasic action potential recordings from the endocardium with special focus on the RV outflow tract could not demonstrate any morphological abnormalities in three Brugada patients. CONCLUSIONS: The presence of a deeply notched action potential in the RV epicardium, but not in endocardium, would be expected to induce a transmural current that would contribute to elevation of the ST-segment in the right precordial leads. The spike-and-dome configuration may also prolong the epicardial action potential, thus contributing to a rapid reversal of the transmural gradients and inscription of an inverted T-wave.

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