Brugada syndrome and ischemia-induced ST-segment elevation. Similarities and differences
José M Di Diego1, Jeffrey M Fish, Charles Antzelevitch
1Experimental Cardiology Department, Masonic Medical Research Laboratory, Utica, NY 13501-1787, USA. didiego@mmrl.edu
Journal of Electrocardiology
|October 18, 2005
Summary
ST-segment elevation in electrocardiograms (ECGs) can stem from acute ischemia or Brugada syndrome. This study reveals that the ion channel Ito plays a key role in modulating ECGs in both conditions, suggesting a shared electrophysiological basis.
Area of Science:
- Cardiovascular Electrophysiology
- Cardiac Arrhythmias
- Electrocardiography
Background:
- ST-segment elevation on ECGs commonly indicates acute myocardial ischemia.
- Brugada syndrome can present with similar ECG findings, particularly when affecting the right ventricular outflow tract.
- The electrophysiological mechanisms underlying these similarities are not fully understood.
Purpose of the Study:
- To investigate the electrophysiological similarities between Brugada syndrome and acute transmural ischemia models.
- To examine the role of the ion channel Ito in modulating ECG manifestations in both conditions.
Main Methods:
- Utilized isolated canine right ventricular wedge preparations.
- Recorded transmembrane action potentials (AP) and transmural pseudo-ECGs.
- Simulated Brugada syndrome using terfenadine and acute ischemia using a no-flow model.
Main Results:
- Ischemia caused ST-segment elevation via AP dome depression/loss or conduction delays.
- Brugada syndrome model also showed ST-segment elevation due to AP dome abnormalities and conduction delays.
- Both models exhibited closely coupled extrasystoles resulting from reentrant phenomena.
Conclusions:
- The ion channel Ito modulates ECG manifestations in both acute ischemia and Brugada syndrome.
- Both clinical conditions likely share a common electrophysiological substrate.
- Understanding these mechanisms can improve diagnosis and treatment strategies.
More Related Videos
Related Concept Videos
01:17Ischemic Heart Disease: Overview
Ischemic heart disease occurs when the heart's blood supply dwindles, causing an ominous lack of oxygen and nutrients. This deficiency, stemming from reduced or obstructed blood flow, spells danger, leading to heart muscle damage and dysfunction.
Atherosclerosis, the primary malefactor, orchestrates this dangerous condition. It manifests as the accumulation of fatty deposits, akin to insidious plaques, within arterial walls. As time elapses, these plaques metamorphose, hardening and narrowing...
Atherosclerosis, the primary malefactor, orchestrates this dangerous condition. It manifests as the accumulation of fatty deposits, akin to insidious plaques, within arterial walls. As time elapses, these plaques metamorphose, hardening and narrowing...
01:26Coronary Artery Disease II: Pathophysiology
Coronary Artery Disease (CAD) originates from a series of events that impair the function of coronary arteries, the blood vessels responsible for delivering oxygen-rich blood to the heart muscle. The pathophysiology of CAD is closely linked to atherosclerosis, a chronic inflammatory and lipid-driven condition affecting the vascular endothelium.1. Endothelial DamageThe process begins with damage to the vascular endothelium, which serves as a protective barrier between the blood and the vessel...
01:30Acute Coronary Syndrome I: Introduction
Acute Coronary Syndrome (ACS) encompasses a spectrum of heart conditions caused by sudden obstruction of coronary arteries, typically resulting from the rupture of an atherosclerotic plaque and subsequent thrombus (blood clot) formation. This obstruction can lead to partial or complete blockage of blood flow, causing varying degrees of myocardial ischemia or infarction.ACS includes the following clinical entities:Unstable Angina (UA)Non-ST-Elevation Myocardial Infarction (NSTEMI)ST-Elevation...
01:30Acute Coronary Syndrome III: Diagnostic Studies
Diagnosing acute coronary syndrome or ACS begins with a thorough patient history. Notable symptoms include central, crushing chest pain radiating to the left arm, neck, jaw, or back, along with shortness of breath, sweating (diaphoresis), nausea, vomiting, dizziness, and palpitations.It is crucial to note any history of cardiac illnesses and assess risk factors, including age, gender, smoking, hypertension, diabetes, hyperlipidemia, and a sedentary lifestyle.During physical examination, vital...
01:15Ischemic Stroke ll: Pathophysiology
An ischemic stroke occurs when a cerebral blood vessel becomes obstructed, most often by a thrombus or embolus, interrupting the delivery of oxygen and glucose to brain tissue. Because neurons rely on continuous aerobic metabolism, energy failure begins within minutes of reduced perfusion. The region receiving the least blood flow becomes the infarct core, an area of irreversible cellular death. Surrounding this core lies the penumbra, a zone of hypoperfused but still viable tissue that is...
01:26Transient Ischemic Attack l: Introduction
A transient ischemic attack (TIA) is a brief episode of neurological dysfunction caused by a temporary, focal reduction in cerebral blood flow. Although symptoms resemble those of an ischemic stroke, the interruption in perfusion is short-lived and does not cause permanent infarction. TIAs are clinically important because they often serve as early warning events for future stroke.Mechanisms of Transient Cerebral IschemiaTransient cerebral ischemia may arise through several mechanisms. One...