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The prevalence and characteristics of silent ischemia (inadequate blood flow to the heart muscle due to constriction or obstruction of coronary arteries, without symptoms) was assessed in patients who had a CABG, or coronary artery bypass graft performed. Following surgery the patients were monitored for 62 months. A number of complications may account for myocardial ischemia after CABG, but it is not known to what extent these factors influence long-term prognosis. Ninety-four individuals were examined by 24-hour ambulatory electrocardiography (ECG) for ST-segment depressions (an abnormal ECG reading indicating a type of heart attack) one to three months after the procedure. Another 184 patients were examined at 12 months. Silent ischemia was also compared with results of angiographies (X-rays of blood vessels that use a radiopaque contrast agent) which were performed to evaluate revascularization of the heart and subsequent adverse reactions. At the early follow-up, 20 percent of the patients had silent ischemia; at the late follow-up, silent ischemia was detected in 27 percent of the patients. No association between CABG and silent ischemia was found, and in patients who had recent CABG silent ischemia was not considered to be predictive of a poor long-term prognosis. Age was the only characteristic that was associated with high risk for additional cardiac disease. It was concluded that in patients with good left ventricular function (effectively pumping blood to the body), an adverse prognosis is not associated with silent ischemia as detected by 24-hour ambulatory ECG one year after CABG surgery.

Myocardial ischemia is a compromised blood supply to the heart muscle that affects patients with coronary artery disease (CAD). Ischemic CAD patients sometimes experience episodes of arrhythmia abnormal heart beats. Life-threatening arrhythmias known as ventricular premature complexes (VPCs) are treated with antiarrhythmic drugs. It is not known whether this therapy actually reduces the risk of sudden death. Long-term antiarrhythmic therapy to prevent VPC was evaluated in 28 patients receiving the antiarrhythmic drug moricizine for one to 56 months. A transient reduction in drug efficacy was evident in 36 percent of the patients at follow-up. An increase in moricizine was needed in four (14 percent) of the patients. The drug ceased to be effective in another four patients (14 percent). Some patients experienced spontaneous resolution of arrhythmias, late arrhythmic events and delayed side effects. Although moricizine is a safe and effective drug for treating arrhythmias, its long-term ability to control arrhythmias is problematic. It is suggested that drug efficacy assessments be made every year. (Consumer Summary produced by Reliance Medical Information, Inc.)

• Nutritional benefits and feeding-related complications were prospectively compared in 53 preterm very-low-birth-weight infants receiving isoenergetic feeding by either the continuous nasogastric (n=30) or intermittent nasogastric (n=23) route. Stepwise regression techniques were used to develop models relating feeding-associated factors. Feeding method significantly affected weight gain in infants 1000 to 1249 g birth weight with continuous nasogastric feeding associated with an additional weight gain of 3.6 to 6.1 g/kg/d. No effects of feeding method on changes in occipitofrontal circumference, triceps skin-fold thickness, bilirubin values, or total protein values were demonstrable. There were few major differences between feeding groups on measures of feeding complications. Continuous nasogastric feeding was fairly well tolerated and resulted in improved weight gain when compared with Intermittent nasogastric feeding in preterm infants 1000 to 1249 g birth weight.(AJDC 1987;141:439-444)

Confusion regarding proper use of the terms rate and risk persists in the literature. This has implications for the proper modeling of prognosis and transition between health states in decision analysis and related techniques. The issue is complicated by the plethora of terms related to rate and risk. Although the suggestion to use the terms force and probability as substitutes for rate and risk has some appeal, the change in terminology by itself is unlikely to solve all the confusion or misuse of terms. This paper clarifies the proper definitions and estimations of rates and risks and suggests critical factors for the decision analyst to re member when using, modeling, or interpreting transition rates and risks. Key words:decision models; rate; risk; force; probability; transitions. (Med Decis Making 1994;14:52-58)