Table 1. Agreement between paired bubble grades from the O’Dive and 2D cardiac imaging including zero grades; weighted Kappa 0.24 (SE 0.017) .

Grades O’Dive	Paired 2D cardiac imaging grades					Total
	0	1	2	3	4
0	256	141	107	132	17	653
1	36	44	35	103	13	231
2	11	13	19	69	13	125
3	1	6	6	54	12	79
4	0	0	0	15	10	25
Total	304	204	167	373	65	1,113