(3) Operation for arrhythmia (total; 4000)

	Cases	30-day mortality		Hospital mortality	Concomitant operation
					Isolated	Congenital	Valve	IHD	Others	Multiple combination
		Hospital	After discharge							2 categories	3 categories
Maze	3763	40 (1.1)	2 (0.05)	59 (1.6)	64	159	3338	479	189	421	28
For WPW	0	0	0	0	0	0	0	0	0	0	0
For ventricular tachyarrythmia	43	1 (2.3)	0	1 (2.3)	3	1	13	23	8	5	0
Others	194	2 (1.0)	0	4 (2.1)	1	19	139	50	24	33	3
Total	4000	43 (1.1)	2 (0.05)	64 (1.6)	68	179	3490	552	221	459	31

Values in parenthesis represent mortality %. Except for 68 isolated cases, all remaining 3932 cases are doubly allocated, one for this subgroup and the other for the subgroup corresponding to the concomitant operations

WPW Wolff–Parkinson–White syndrome, IHD ischemic heart disease