For more than a century, it has been known that the body recoils each time the heart ejects blood into the arteries. These subtle cardiogenic body movements have been measured with increasingly convenient ballistocardiography (BCG) instruments over the years. A typical BCG measurement shows several waves, most notably the “I”, “J”, and “K” waves. However, the mechanism for the genesis of these waves has remained elusive. We formulated a simple mathematical model of the BCG waveform. We showed that the model could predict the BCG waves as well as physiologic timings and amplitudes of the major waves. The validated model reveals that the principal mechanism for the genesis of the BCG waves is blood pressure gradients in the ascending and descending aorta. This new mechanistic insight may be exploited to allow BCG to realize its potential for unobtrusive monitoring and diagnosis of cardiovascular health and disease.

A significant proportion of health care resources are consumed at end of life. As a result, decision and policy makers seek cost savings to enhance program planning. Most literature, however, combines the cost of all dying patients and, subsequently, fails to recognize the variation between trajectories of functional decline and utilization of health care services. In this article, we classified dying Albertans by categories of functional decline and assessed their utilization and costs. We used data from two years of health care utilization and costs for three annual cohorts of permanent residents of Alberta, Canada (April 1999 to March 2002). Literature, expert opinion, and cluster analysis were used to categorize the deceased according to sudden death, terminal illness, organ failure, frailty, and other causes of death. Expenditures were decomposed into constituent quantities and prices. We found that nearly 18,000 die per year in Alberta: sudden death (7.1%), terminal illness (29.8%), organ failure (30.5%), frailty (30.2%), and other causes (2.3%). Inpatient care remains the primary cost driver for all trajectories. Significant and predictable health care services are required by noncancer patients. Trajectories of costs are significantly different for the four categories of dying Albertans. Trajectories of dying are a useful classification for analyzing health care use and costs.

1 This study examined effects of adenosine and selective adenosine A, and A2 receptor agonists on glucose metabolism in rat isolated working hearts perfused under aerobic conditions and during reperfusion after 35 min of global no-flow ischaemia.2 Hearts were perfused with a modified Krebs-Henseleit buffer containing 1.25 mM Ca2+, 11 mM glucose, 1.2 mM palmitate and insulin (100 Mu ml-'), and paced at 280 beats min-'. Rates of glycolysis and glucose oxidation were measured from the quantitative production of 3H20 and "'CO2, respectively, from [5-3H/U-"'C]-glucose.3 Under aerobic conditions, adenosine (100 Mm) and the adenosine A, receptor agonist, N6-cyclohexyladenosine (CHA, 0.05 gM), inhibited glycolysis but had no effect on either glucose oxidation or mechanical function (as assessed by heart rate systolic pressure product). The improved coupling of glycolysis to glucose oxidation reduced the calculated rate of proton production from glucose metabolism. The adenosine Al receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX 0.3 MM) did not alter glycolysis or glucose oxidation per se but completely antagonized the adenosine-and CHAinduced inhibition of glycolysis and proton production.4 During aerobic reperfusion following ischaemia, CHA (0.05 gM) again inhibited glycolysis and proton production from glucose metabolism and had no effect on glucose oxidation. CHA also significantly enhanced the recovery of mechanical function. In contrast, the selective adenosine A2, receptor agonist, CGS-21680 (1.0 yM), exerted no metabolic or mechanical effects. Similar profiles of action were seen if these agonists were present during ischaemia and throughout reperfusion or when they were present only during reperfusion. 5 DPCPX (0.3 uM), added at reperfusion, antagonized the CHA-induced improvement in mechanical function. It also significantly depressed the recovery of mechanical function per se during reperfusion.Both the metabolic and mechanical effects of adenosine (100 gM) were antagonized by the nonselective Al/A2 antagonist, 8-sulphophenyltheophylline (100 yM).6 These data demonstrate that inhibition of glycolysis and improved recovery of mechanical function during reperfusion of rat isolated hearts are mediated by an adenosine Al receptor mechanism. Improved coupling of glycolysis and glucose oxidation during reperfusion may contribute to the enhanced recovery of mechanical function by decreasing proton production from glucose metabolism and the potential for intracellular Ca2+ accumulation, which if not corrected leads to mechanical dysfunction of the postischaemic myocardium.

RIPC applied during isoflurane inhalation provides no benefit to the myocardium of patients undergoing on-pump coronary artery bypass grafting.

We collected the respiratory mucus coating the endotracheal tubes used during short surgical procedures in 27 patients with no clinical evidence of respiratory disease. Twelve were male and 15 were female, and they ranged from 1 to 64 yr of age (mean, 28.7 yr). The viscoelastic properties, frog palate transport rate, and percent solid composition were in the normal range reported for both canine and human mucus collected using the bronchoscopy brush technique. There were no significant differences noted between male and female patients, and there were no changes in mucus or transport properties seen with aging. Mucus was also collected separately from the inside of the tube exposed to constant gas flow (13 patients), and from the outside of the endotracheal tubes in 25 patients. Although there were no significant differences in viscoelastic properties between inside and outside mucus, there was a greater thread formation (filance, 45 versus 26 mm; p less than 0.005) and a higher percentage of solids in mucus from the inside of the endotracheal tube (15.9 versus 11.4%; p less than 0.05), which is compatible with reduced hydration. The duration of anesthesia ranged from 25 to 195 min (mean, 85 min). There was no effect of duration of anesthesia on any of the measured mucus properties. This technique for mucus collection allows us to study alterations in mucus properties in patients with and without pulmonary disease at the time of incidental surgery.(ABSTRACT TRUNCATED AT 250 WORDS)