Click on image to view larger version.
Figure 4 Correlations between the structural (% diameter stenosis, n = 50; horizontal axis; top panel) and the functional (distal coronary flow velocity reserve, n = 12; horizontal axis; bottom panel) stenosis severity of the contralateral coronary artery and the adenosine-induced collateral flow index change (delta CFIp, vertical axis). The regression equations provided describe the mentioned relations in patients with good collaterals. There were no respective associations in patients with poor collaterals. Closed symbols: patients with good collaterals (angiographic degree 
2); crossed symbols: patients with poor collaterals (degree <2).