Table 1.

Mean values and standard errors of Pearson's correlation coefficients (r) between k and j intervals in clusters determined for patients with atrial fibrillation (AF) and healthy subjects.

Clusters	AF		Healthy		Z	p
	N	r	N	r
1st	121	0.161±0.016	50	0.627±0.021	−9.692	0.001
2nd	21	0.084±0.017	18	0.428±0.027	−5.324	0.001
3rd	41	0.227±0.033	7	0.388±0.014	−1.738	0.082
4th	46	0.296±0.034	20	0.4768±0.0013	−5.302	0.001