T wave alternans

T wave alternans is a electrocardiographic phenomenon characterized by alternating changes in the morphology of T waves. It is often associated with serious cardiac arrhythmias, including ventricular tachycardia and ventricular fibrillation, and is considered a marker of increased risk for sudden cardiac death.

History

The phenomenon of T wave alternans was first described in the early 20th century. However, it was not until the advent of modern electrocardiographic technology that its clinical significance was fully appreciated.

Mechanism

The exact mechanism of T wave alternans is not fully understood. It is thought to be related to alternations in the action potential of the cardiac muscle cells, which can lead to a disruption in the normal electrical conduction of the heart.

Clinical significance

T wave alternans is considered a marker of increased risk for serious cardiac arrhythmias, including ventricular tachycardia and ventricular fibrillation. It is often detected in patients with ischemic heart disease, cardiomyopathy, and other conditions that can affect the electrical conduction of the heart.

Detection

T wave alternans can be detected using a variety of electrocardiographic techniques, including Holter monitoring, exercise stress testing, and signal-averaged electrocardiography. The presence of T wave alternans is often a sign of underlying cardiac disease and may warrant further investigation.

Treatment

The treatment of T wave alternans is primarily focused on managing the underlying cardiac disease and preventing the occurrence of serious cardiac arrhythmias. This may involve the use of antiarrhythmic medications, pacemaker implantation, or cardiac resynchronization therapy.