Table 2. Agreement between paired bubble grades from the O’Dive and 2D cardiac imaging excluding zero grades; weighted Kappa 0.16 (SE: 0.026) .

Grades O’Dive	Paired 2D cardiac imaging grades				Total
	1	2	3	4
1	44	35	103	13	195
2	13	19	69	13	114
3	6	6	54	12	78
4	0	0	15	10	25
Total	63	60	241	48	412