Administration of an intravenous perfluorocarbon contrast agent improves echocardiographic determination of left ventricular volumes and ejection fraction: comparison with cine magnetic resonance imaging

AbstractObjectives. The purpose of this study was to determine whether contrast-enhanced transthoracic echocardiography improves the evaluation of left ventricular (LV) volumes and ejection fraction (EF).Background. Echocardiographic assessment of LV volumes and EF is widely used but may be inaccurate when the endocardium is not completely visualized. Recently the intravenous (IV) administration of perfluorocarbon microbubbles has been shown to enhance opacification of the LV cavity, but the utility of these agents to improve the echocardiographic assessment of LV systolic function is unknown.Methods. In 40 subjects (29 men and 11 women, aged 24 to 81 years) an assessment of LV volumes and EF was performed with a magnetic resonance imaging examination, followed immediately by a transthoracic echocardiogram before and after the intravenous administration of 2% dodecafluoropentane emulsion (EchoGen; Sonus Pharmaceuticals, Bothell, Washington).Results. Contrast enhanced the echocardiographic assessment of LV end diastolic volume (p < 0.02), end systolic volume (p < 0.01) and LVEF (p < 0.03). The percentage of subjects in whom the correct echocardiographic classification EF was normal, mild to moderately depressed or severely reduced improved significantly after contrast enhancement (from 71% before contrast to 94% after, p < 0.03). These findings were most striking in the subjects with two or more adjacent endocardial segments not visualized at baseline.Conclusions. Administration of an intravenous contrast agent improves the ability to accurately assess LV volumes and EF in humans. Contrast enhancement is most useful in subjects with two or more adjacent endocardial segments not seen at baseline

The association of heart rate recovery immediately after exercise with coronary artery calcium: the coronary artery risk development in young adults study

We tested whether slower heart rate recovery (HRR) following graded exercise treadmill testing (GXT) was associated with the presence of coronary artery calcium (CAC). Participants (n = 2,648) ages 18–30 years at baseline examination underwent GXT, followed by CAC screening 15 years later. Slow HRR was not associated with higher odds of testing positive (yes/no) for CAC at year 15 (OR = 0.99, p = 0.91 per standard deviation change in HRR). Slow HRR in young adulthood is not associated with the presence of CAC at middle age

Proliferation Index in Various Stages of Breast Cancer Determined by Ki-67 Immunostaining

To investigate factors involved in progression of breast cancer, we estimated the growth fraction of malignant cell populations in various stages of mammary cancer growth. Frozen sections were immunostained with the Ki-67 monoclonal antibody and the proliferation index determined using static image analysis. Pure intraductal carcinoma, intraductal carcinoma coexisting with invasive disease, and metastatic sites coexisting with primary tumors were studied. The proliferation index of pure intraductal carcinomas (mean 4.5%, median 1.8%) was not significantly different from invasive mammary cancers (mean 5.1%, median 2.2%). The proliferation index determined for the in situ component of primary cancers (mean 3.8%, median 1.5%) was not significantly different from values obtained from the invasive component of growth (mean 4.2%, median 2.1%). Variability between in situ and invasive components for individual cases was minimal in tumors whose proliferation index was less than 3.0%; for tumors with higher proliferation indices, the differences were greater. However, there was no trend toward a decrease or increase in growth fraction for the two components of primary tumor growth. The mean proliferative index for primary tumors (mean 4.9%, median 4.0%) was not significantly different from the mean proliferative score from a matched group of metastatic sites in the same patients (mean 5.7%, median 5.5%). Comparison of individual cases uncovered differences in some tumors; again no consistent trends in either direction were noted. An increase (or decrease) in growth activity does not accompany the transition from intraductal (in situ) disease to invasive mammary cancer, nor does a change in growth fraction necessarily accompany progression of mammary cancer from the primary to regional metastatic site

Proliferation Index in Various Stages of Breast Cancer Determined by Ki-67 Immunostaining

To investigate factors involved in progression of breast cancer, we estimated the growth fraction of malignant cell populations in various stages of mammary cancer growth. Frozen sections were immunostained with the Ki-67 monoclonal antibody and the proliferation index determined using static image analysis. Pure intraductal carcinoma, intraductal carcinoma coexisting with invasive disease, and metastatic sites coexisting with primary tumors were studied. The proliferation index of pure intraductal carcinomas (mean 4.5%, median 1.8%) was not significantly different from invasive mammary cancers (mean 5.1%, median 2.2%). The proliferation index determined for the in situ component of primary cancers (mean 3.8%, median 1.5%) was not significantly different from values obtained from the invasive component of growth (mean 4.2%, median 2.1%). Variability between in situ and invasive components for individual cases was minimal in tumors whose proliferation index was less than 3.0%; for tumors with higher proliferation indices, the differences were greater. However, there was no trend toward a decrease or increase in growth fraction for the two components of primary tumor growth. The mean proliferative index for primary tumors (mean 4.9%, median 4.0%) was not significantly different from the mean proliferative score from a matched group of metastatic sites in the same patients (mean 5.7%, median 5.5%). Comparison of individual cases uncovered differences in some tumors; again no consistent trends in either direction were noted. An increase (or decrease) in growth activity does not accompany the transition from intraductal (in situ) disease to invasive mammary cancer, nor does a change in growth fraction necessarily accompany progression of mammary cancer from the primary to regional metastatic site