[Pulmonary alveolar microlithiasis].

Table 1 in the article by Mathru et al’ shows that when the pericardium was opened, the cardiac index fell from 2.9 to 2.8, coupled with a rise in heart rate from 63 to 64. This should cause a fall in stroke volume of5.0 percent, not the 1.7 percent rise (from 59 to 60 ml) claimed in Table 2 in that article. Likewise, Table 3 shows no change in cardiac index. However, that cardiac index value coupled with an increase in heart rate from 66.9 to 69.5 together should cause a fall in stroke volume of3.7 percent, not the 16.3 percent increase (from 66. 1 to 76.9 ml) shown in Table 4. The total errors of 6.7 percent in group 1 and 20.0 percent in group 2 imply a large enough error in stroke volume and RVEF to call into question the authors’ conclusions that the “right ventricle enlarges after opening the pericardium,” and that the RVEF decreased in group 1 but not in group 2. Also, with such large differences between RVEF (39. 1 percent and 36.8 percent) and ejection fraction area (55 percent and 61 percent) in group 2, studies are needed to determine whether either technique, RVEF thermodilution or echocardiography, is accurate.