New Device Helps Treat Abnormal Heart Rhythms

	May 11, 1999 - Improvements in a device 
used to map heart tissue for irregular heart 
rhythms will benefit more patients when this 
tissue is then removed. The treatment, called 
radiofrequency ablation or RFA, finds and destroys
with radiowaves, heart cells where abnormal heart
beats begin.
	The researchers have changed the standard
catheter. Current catheters have 4-10 electrodes 
that map the heart's electric activity. This improved
catheter has 64 electrodes, which read signals from 
many different directions at once, researchers report
in Circulation: Journal of the American Heart 
Association.
	The new "basket" catheter is inserted into a
large vein and guided to the heart, where it is used 
to create a 3D map of electrical activity. It pin-
points the source of abnormal heart rhythm more 
quickly than the standard procedure.
	All patients in the new study had a fast heart
arrhythmia called atrial tachycardia. This places a 
burden on the heart and may lead to CHF, which occurs
when the heart cannot pump enough blood to meet the 
body's needs.
	The research team, led by Dr. Schmitt, 
identified the tissue source of abnormal heartbeats in
31 patients using the new catheter. They used RFA to 
treat 16 patients. Of these patients, 15 were cured and
no one had any complications. The new catheter may also
be used in patients with other types of irregular heart
rhythms, they suggest.
	"Because the electrode technique currently used
for detecting abnormal heart rhythm is time-consuming 
and difficult, it is not suitable for all patients with 
irregular beats. So, many people who might benefit from
RFA are not able to," Schmitt said in a written statement.
	"The multi-electrode basket catheter adds a new 
dimension to mapping the heart's electrical signals for 
better treatment of abnormal heartbeats," he added.

Circulation: Journal of the American Heart Association 1999;99