Bicomponent analysis of the contractile capacity of the heart in ischemic lesions of the myocardium (experimento-clinical study)

A study was made of cardiac pumping capacity in animals with local myocardial ischemia (9 experiments on cats), in 25 healthy persons and 21 patients suffering from coronary heart disease with stage I-IIA circulatory insufficiency using afterload characteristics (ALC). The latter reflected correlation between left ventricular pressure and aortic blood flow in constant blood filling and in a given inotropic heart condition. For combined assessment of ALC one should know its two parameters: power (maximum pressure in the zero blood flow) and rate (maximum blood flow rate in zero antipressure). It was shown that early stages of cardiac insufficiency were characterized both under experimental and clinical conditions by change in the inclination angle of an afterload curve and a shift of a working point on it to the right.     

Sensitivity and specificity of first screen mammography in the Canadian National Breast Screening Study: a preliminary report from five centers

Sensitivity and specificity of first screen mammography in a randomized screening trial at five centers are reported. A total of 23,101 women underwent mammography; in 139, breast cancer was detected at first screening; in 20, less than 12 months after first screening; and in 47, at second screening. All 206 cancer cases were histologically confirmed, and 174 were defined as being detectable at first screening. Average length of follow-up for all women was 3.2 years. Interpretations of first screen mammograms by the center radiologists were matched to known outcomes. Simultaneous blind review was performed by a single reference radiologist with mammograms from all 206 cancer cases and those of a random sample of 739 women not known to have breast cancer at 15 months or more after initial screening. Overall, the five screening centers achieved a sensitivity of 69% (range, 60%-78%), a specificity of 94% (range, 93%-96%), a positive predictive value of 8.6% (range, 3%-16%), and a negative predictive value of 99.7% (range, 99.6%-99.9%).