Background: The prerequisite for catheter ablation is exact mapping during the electrophysiological study. Difficult catheter orientation and navigation associated with conventional technology may complicate the procedure. We evaluated the usefulness of three-dimensional electroanatomical mapping in atrial flutter ablation. Methods and Results: Electroanatomical mapping of the right atrium was done in ten patients during atrial tachycardia. Eight individuals were male(80%). Mean age was 55 years. Average duration of symptoms was 21.3 months. In electroanatomical mapping, average map point was 150.8. Mean mapping time was 57.6 minutes. Average RA volume and length of isthmus were 145.9cc and 17.42mm, respectively. Mean follow up duration was 5.5 months. Other results are as follows:Conclusion: Three-dimensional electroanatomical mapping of the right atrium allows detailed reconstruction of the chamber geometry and activation sequence. It is useful in understanding the mechanism of post-op atrial tachycardia and guiding catheter ablation of atrial flutter.

Patient No	Past Hx	Dx	Map points	Map time(min)	RA volume	Tachy CL(msec)	block	recur
1	S/P DVR	CCW	124	70	187.93	275	Bi-block	no
2	S/P TOF	CW	340	92	137.57	295	Block(-)	no
3	none	CCW	187	40	114.91	240	Uni-block	no
4	none	CCW	197	70	137.42	185	Block(-)	yes
5	S/P MVR	CCW	217	106	202.51	322	Bi-block	no
6	none	atypical	100	26	85.2	193	Fail	.
7	none	CCW	75	57	148.78	226	Bi-block	no
8	none	CW	66	30	143.43	238	Uni-block	no
9	S/P ASD	CCW	75	33	121.82	326	Bi-block	no
10	S/P CABG	CCW	127	52	179.54	250	Block(-)	no
CCW: counterclockwise flutter, CW: clockwise flutter, atypical: atypical flutter, Bi: bidirectional, Uni: unidirectional