The unexpected death of NBC Meet the Press host Tim Russert in June shocked many Americans, who suddenly saw themselves at risk for heart trouble. Heart-healthy diets gained traction in 2008, along with tips for recognizing symptoms of heart disease.
Those topics are among the most viewed heart-related stories on WebMD for 2008.
Whole Grains Fight Belly Fat
Tim Russert's Death: Questions, Answers
Recognizing Women's Heart Attack Symptoms
Treatment depends on the type of SVT and what is causing it, if known. Treatment might include medicines that slow the heart rate or a procedure called catheter ablation that stops the rhythm problem.
Atrial fibrillation or flutter
Atrial fibrillation is the most common type of
SVT. It means that the heart's upper chambers (atria) beat irregularly.
Atrial flutter is like atrial fibrillation, because the electrical problem is in the atria. But with atrial flutter, the heart beats very fast in a regular rhythm. Atrial flutter is less common than atrial fibrillation.
Atrioventricular nodal reentrant tachycardia
Atrioventricular nodal reentrant
tachycardia (AVNRT) is a common type of
supraventricular tachycardia. It accounts for many of
the fast heart rates that start in the upper part of the heart (excluding
atrial fibrillation). Atrioventricular (AV) nodal reentrant tachycardia can
cause symptoms at any age. It typically is not
a result of other forms of heart disease.
AVNRT is caused by an abnormal or extra
electrical pathway in the heart, a kind of "short circuit." Electrical pathways
in the heart consist of microscopic muscle fibers that conduct electrical
impulses. Normally, a single electrical pathway allows impulses to travel from
the upper to the lower chambers. An extra electrical pathway in the AV node allows those
impulses to travel backward at the same time, starting another heartbeat.
During AVNRT the electrical impulses continuously go
around the two pathways. This is known as "reentry" and can lead to a very fast
Atrioventricular reciprocating tachycardia
Atrioventricular reciprocating tachycardia (AVRT) occurs when there
is an extra electrical pathway linking the upper (atria) and lower (ventricles)
chambers of the heart.
AV node is the only tissue that conducts electrical
impulses between the upper and lower chambers of the heart. All electrical
impulses must go through the AV node to reach the lower chambers of the heart.
In an atrioventricular reciprocating tachycardia, electrical impulses travel
one direction in the normal manner, down the AV node to the lower chambers
(ventricles), but they then travel back up to the upper chambers (atria)
through an abnormal, extra electrical pathway (accessory pathway) located
outside the AV node.
Symptoms may start
during the teen or young adult years.