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Swine models of chronic hyperfusion were analyzed by positron emission tomography to determine the effects of chronic myocardial ischemia on radiolabelled regional glucose uptake. Analysis of swine hearts instrumented with external constrictors in the left anterior descending coronary artery indicated the presence of enhanced glucose uptake and normal bioenergetics. Furthermore, the presence of normal bioenergetics in dysfunctional myocardial regions exhibited the adaption of the myocardium to chronic hyperfusion.

Abstract Background The value of Single Photon Emission Computed Tomography stress myocardial perfusion imaging (SPECT-MPI) for detecting graft disease after coronary artery bypass surgery (CABG) has not been studied prospectively in an unselected cohort. Methods Radial Artery Versus Saphenous Vein Graft Study is a Veterans Affairs Cooperative Study to determine graft patency rates after CABG surgery. Seventy-nine participants agreed to SPECT-MPI within 24 hours of their coronary angiogram, one-year after CABG. The choice of the stress protocol was made at the discretion of the nuclear radiologist and was either a symptom-limited exercise test (n = 68) or an adenosine infusion (n = 11). The SPECT-MPI results were interpreted independent of the angiographic results and estimates of sensitivity, specificity and accuracy were based on the prediction of a graft stenosis of ≥70% on coronary angiogram. Results A significant stenosis was present in 38 (48%) of 79 patients and 56 (22%) of 251 grafts. In those stress tests with an optimal exercise heart rate response (>80% maximum predicted heart rate) (n = 26) sensitivity, specificity and accuracy of SPECT-MPI for predicting the graft stenosis was 77%, 69% and 73% respectively. With adenosine (n = 11) it was 75%, 57% and 64%, respectively. Among participants with a suboptimal exercise heart rate response, the sensitivity of SPECT-MPI for predicting a graft stenosis was Conclusions Under optimal stress conditions, SPECT-MPI has a good sensitivity and accuracy for detecting graft disease in an unselected patient population 1 year post-CABG.

Abstract Background Previous studies on the effects of Statins in preventing atrial fibrillation (AF) after cardiac surgery have shown conflicting results. Whether statins prevent AF in patients treated with postoperative beta blockers and whether the statin-effect is dose related are unknown. Methods We retrospectively studied 1936 consecutive patients who underwent coronary artery bypass graft (CABG) (n = 1493) or valve surgery (n = 443) at the Minneapolis Veterans Affairs Medical Center. All patients were in sinus rhythm before the surgery. Postoperative beta blockers were administered routinely (92% within 24 hours postoperatively). Results Mean age was 66+10 years and 68% of the patients were taking Statins. Postoperative AF occurred in 588 (30%) patients and led to longer length of stay in the intensive care unit versus those without AF (5.1+7.6 days versus 2.5+2.3 days, p < 0.0001). Patients with a past history of AF had a 5 times higher risk of postoperative AF (odds ratio 5.1; 95% confidence interval 3.4 to 7.7; p < 0.0001). AF occurred in 31% of patients taking statins versus 29% of the others (p = 0.49). In multivariable analysis, statins were not associated with AF (odds ratio (OR) 0.93, 95% confidence interval (CI) 0.7 to 1.2; p = 0.59). However, in a subgroup analysis, the patients treated with Simvastatin >20 mg daily had a 36% reduction in the risk of postoperative AF (OR 0.64, 95% CI 0.43 to 0.6; p = 0.03) in comparison to those taking lower dosages. Conclusion Among cardiac surgery patients treated with postoperative beta blockers Statin treatment reduces the incidence of postoperative AF when used at higher dosages

McFalls, Edward O., Douglas Baldwin, David Marx, Peggy Fashingbauer, and Herbert B. Ward. Effect of regional hyperemia on myocardial uptake of 2-deoxy-2-[[sup.18]F] fluoro-D-glucose. Am. J. Physiol. Endocrinol. Metab. 278: E96-E 102, 2000.--2-Deoxy-2- [[sup.18]F]fluoro-D-glucose (FDG) may be used to predict glucose kinetics when the factor relating differences in transport and phosphorylation between compounds remains constant ('lumped constant'). It is not clear whether hyperemia alters that factor. In anesthetized swine, myocardial FDG uptake was estimated by positron emission tomography, during an intracoronary infusion of either adenosine, ATP, or bradykinin (40 [micro]g [multiplied by] [kg.sup.-1] [multiplied by] [min.sup.-1], 40 [micro]g [multiplied by] [kg.sup.-1] [multiplied by] [min.sup.-1], and 2 nmol [multiplied by] [kg.sup.-1] [multiplied by] [min.sup.-1], respectively; n = 6 for all groups). In controls during normal perfusion (n = 6), FDG uptake was 0.78 [+ or -] 0.32 [micro]mol [multiplied by] [g.sup.-1] [multiplied by] [min.sup.-1], whereas glucose uptake by Fick was 0.71 [+ or -] 0.25 [micro]mol [multiplied by] [g.sup.-1] [multiplied by] [min.sup.-1] (r = 0.73; P [is less than] 0.05). Adenosine increased blood flow from 1.29 [+ or -] 0.43 to 4.80 [+ or -] 2.19 ml [multiplied by] [g.sup.-1] [multiplied by] [min.sup.-1] (P [is less than] 0.05) and glucose uptake from 1.16 [+ or -] 1.10 to 3.35 [+ or -] 2.12 [micro]mol [multiplied by] [g.sup.-1] [multiplied by] [min.sup.-1] (P [is less than] 0.05), whereas FDG uptake in the hyperemic region was lower than remote regions (0.46 [+ or -] 0.29 and 0.95 [+ or -] 0.55 [micro]mol [multiplied by] [g.sup.-1] [multiplied by] [min.sup.-1], respectively; P [is less than] 0.05). In the ATP and bradykinin groups, blood flow increased four- and twofold, respectively, with no net change in glucose uptake. FDG uptake in the hyperemic region was also significantly lower than remote regions. For all animals, the ratio of blood flow in the hyperemic region relative to remote region was inversely proportional to the ratio of FDG uptake in the same regions ([r.sup.2]=0.73; P [is less than] 0.001) Because nitric oxide elaboration during hyperemia could potentially alter substrate preference and FDG kinetics, six additional swine were studied during maximal adenosine before and after intracoronary [N.sup.G]-monomethyl-L-arginine (1.5 mg/kg). Inhibition of nitric oxide had no effect on either regional myocardial substrate uptake or FDG accumulation. In conclusion, hyperemia decreased regional myocardial FDG uptake relative to normally perfused regions and this effect on the lumped constant was independent of nitric oxide. positron emission tomography; swine; glucose metabolism; adenosine; vasodilatation; nitric oxide

Background The objective of this study was to compare the incidence and prevalence of depressive symptoms in atypical parkinsonian ( APD) syndromes versus Parkinson disease ( PD). Methods In a large, retrospective patient cohort, the authors analyzed the incidence and prevalence of depressive symptoms using the Beck Depression Inventory and evaluated patients longitudinally on subsequent visits. For individuals who were followed at subsequent visits, incidence rates were calculated in person-years as a measure of incidence. Results In total, 361 patients were identified who had APD syndromes, including progressive supranuclear palsy, corticobasal degeneration, multiple system atrophy, and dementia with Lewy bodies; and 2352 patients with PD were used as a control group. The mean Beck Depression Inventory values were significantly higher in patients with APD (F = 14.19; P < 0.001). A significantly higher proportion of those with APD screened positive for depressive symptoms both at the initial visit and on subsequent visits ( P < 0.001), and depressive symptoms appeared to be more severe in the APD subgroups. Unified Parkinson's Disease Rating Scale motor scores and disease duration were correlated with depressive symptoms. Conclusions The current results suggest that the incidence and prevalence of depressive symptoms are higher in patients with APD syndromes and also appear to be more severe than those in patients with PD. Depressive symptoms in APD are common and affect patients regardless of disease duration or motor severity. [ABSTRACT FROM AUTHOR]