Radionuclide Assessment of the Natural Heart Ejection Fraction before and after LVAD Implantation

Complete pressure unloading of the ventricles can preserve ischemically damaged myocardium. Most clinical left heart assist device (LVAD) systems used after ischemic injury of the heart apply atrial cannulation which does not ensure pressure unloading. In order to assess the effect of the implantation of an intracorporeal LVAD on the function of the natural heart, we determined the ejection fraction (EF) in four male Holstein calves (90–105 kg) before and after insertion of a Cleveland Clinic pneumatic LVAD. A gated blood pool scan was obtained with a gamma camera after injection of 40 mCi Tc-labelled albumin. The animals were restrained in a sling to avoid movement artifacts.

All animals showed a drop of 65 ± 12% to 42 ± 14% EF in the first postoperative (p.o.) week. Left ventricular output did not maintain sufficient blood pressure as assessed by pump-off tests. Systolic blood pressure dropped from 122 ±6.5 mm Hg to 81 ± 6 mm Hg without pump support on the morning of the first p.o. day.

Apical coring and possible restrained heart movement by the implanted LVAD may lead to impaired myocardial function that renders the individual LVAD dependent until adaptative corrections take place.

Abdominal fat distribution in pre- and postmenopausal women: The impact of physical activity, age, and menopausal status

Age-related increases in total body fat have been reported, but the impact of menopause on abdominal fat distribution is still unclear. The purpose of this study was to determine the impact of menopausal status on abdominal fat distribution using magnetic resonance imaging (MRI). In addition, we investigated the influence of abdominal fat distribution on blood lipid profiles and leptin concentrations. Twenty-three premenopausal (PRE), 27 postmenopausal (POST), and 28 postmenopausal women on estrogen replacement therapy (ERT) had measurements of regional abdominal fat, blood lipids, and serum leptin concentrations. The women were matched for body mass index (BMI) and total body fat mass. Age and menopausal status were not found to be significant predictors of total abdominal fat, visceral fat, or subcutaneous fat, while physical activity was a significant predictor (P <.01) for total abdominal fat (R(2) =.16), visceral fat (R(2) =.32) and percent visceral fat (R(2) =.25). There was a trend for a greater visceral fat content in the POST women compared with the PRE women (2,495.0 +/- 228.4 v 1,770.4 +/- 240.8 cm(2), respectively, P =.06). The percent visceral abdominal fat was significantly lower (P <.05) in the premenopausal women than in either postmenopausal group (PRE, 23.2% +/- 1.7%; POST, 28.9% +/- 1.8%; ERT, 28.9% +/- 1.6%). Menopausal status and age did not influence any of the blood lipid values. Abdominal fat distribution was a significant predictor of cholesterol concentrations and the cholesterol/high-density lipoprotein-cholesterol (HDL-C) ratio, but only accounted for approximately 15% of the variability in these levels. Total body fat and physical activity accounted for 47% of the variability in leptin concentrations, while abdominal fat distribution, age, and menopausal status were not significant predictors. In conclusion, in early postmenopausal women, the level of physical activity accounts for the variability in abdominal fat distribution observed, while menopausal status and age do not play a significant role. ERT was not associated with additional benefits in abdominal fat distribution compared with postmenopausal women not on ERT or in the blood lipid profile in these women.

Invasive aspergillosis diagnosed by fine-needle aspiration of the thyroid gland

Invasive aspergillosis has been increasingly recognized as causing significant morbidity and mortality in immunocompromised patients but has never been diagnosed by fine-needle thyroid aspiration. A 24-year-old female with systemic lupus erythematosus presented with cough, shortness of breath, and fever of unknown origin unresponsive to broad-spectrum antibiotics. History and physical examination failed to indicate a source of infection. An 111In white blood cell scan showed thyroid localization. Physical examination revealed a multinodular goiter with a left dominant nodule. Fine-needle aspiration biopsy of a thyroid nodule revealed branching hyphae suggestive of Aspergillus sp. Despite immediate and aggressive treatment with amphotericin B and fluconazole, the patient died of overwhelming infection.

Familial dementia caused by polymerization of mutant neuroserpin

Aberrant protein processing with tissue deposition is associated with many common neurodegenerative disorders; however, the complex interplay of genetic and environmental factors has made it difficult to decipher the sequence of events linking protein aggregation with clinical disease. Substantial progress has been made toward understanding the pathophysiology of prototypical conformational diseases and protein polymerization in the superfamily of serine proteinase inhibitors (serpins). Here we describe a new disease, familial encephalopathy with neuroserpin inclusion bodies, characterized clinically as an autosomal dominantly inherited dementia, histologically by unique neuronal inclusion bodies and biochemically by polymers of the neuron-specific serpin, neuroserpin. We report the cosegregation of point mutations in the neuroserpin gene (PI12) with the disease in two families. The significance of one mutation, S49P, is evident from its homology to a previously described serpin mutations, whereas that of the other, S52R, is predicted by modelling of the serpin template. Our findings provide a molecular mechanism for a familial dementia and imply that inhibitors of protein polymerization may be effective therapies for this disorder and perhaps for other more common neurodegenerative diseases.

Radionuclide assessment of the natural heart ejection fraction before and after LVAD implantation

Complete pressure unloading of the ventricles can preserve ischemically damaged myocardium. Most clinical left heart assist device (LVAD) systems used after ischemic injury of the heart apply atrial cannulation which does not ensure pressure unloading. In order to assess the effect of the implantation of an intracorporeal LVAD on the function of the natural heart, we determined the ejection fraction (EF) in four male Holstein calves (90-105 kg) before and after insertion of a Cleveland Clinic pneumatic LVAD. A gated blood pool scan was obtained with a gamma camera after injection of 40 mCi Tc-labelled albumin. The animals were restrained in a sling to avoid movement artifacts. All animals showed a drop of 65 +/- 12% to 42 +/- 14% EF in the first postoperative (p.o.) week. Left ventricular output did not maintain sufficient blood pressure as assessed by pump-off tests. Systolic blood pressure dropped from 122 +/- 6.5 mm Hg to 81 +/- 6 mm Hg without pump support on the morning of the first p.o. day. Apical coring and possible restrained heart movement by the implanted LVAD may lead to impaired myocardial function that renders the individual LVAD dependent until adaptative corrections take place.

Gallium-67 scanning in the diagnosis of postoperative sternal osteomyelitis: concise communication

Sternal osteomyelitis is an uncommon but serious complication of the median sternotomy incision. Definite diagnosis is clinically difficult and radionuclide scanning is of uncertain value in the early postoperative period. We conducted a prospective blind study of gallium scanning in the early period after cardiac surgery and reviewed clinically diagnosed cases that also had scans. Clinical status and scan interpretation were each independently assessed by three raters. Thirty-eight scans included six true positives, five true negatives (no sternotomy) and 27 post-sternotomy, clinically uninfected patients. Using categories of high, medium, and low for scan interpretation, the radiologic assessors agreed 90% of the time. Normal postoperative Ga-67 uptake could usually be differentiated from uptake by an infected sternum. The test had a sensitivity of 83% and specificity 96%. If the clinical (pretest) likelihood of sternal osteomyelitis is 30%, then the gallium scan will have a 90% positive predictive value and a 93% negative predictive value. This study of observer variation and validity indicates that Ga-67 scanning may be useful in confirming the diagnosis of poststernotomy sternal osteomyelitis.

67Gallium lung scans in progressive systemic sclerosis

67Gallium lung scans were performed in 19 patients with progressive systemic sclerosis (scleroderma). Results were expressed quantitatively as the 67Gallium Uptake Index. The mean total pulmonary 67Gallium Uptake Index in patients was significantly higher than that in controls (41 versus 25), and 4 patients (21%) fell outside the normal range. There were no clinical or laboratory variables that correlated with the 56gallium uptake. Increased pulmonary 67gallium uptake in scleroderma may prove useful as an index of pulmonary disease activity.

Assessment of right ventricular function during supine bicycle exercise after Mustard's operation

Right ventricular (RV) performance during supine bicycle exercise was evaluated by gated equilibrium nuclear angiography in 19 clinically well children with d-transposition of the great arteries (d-TGA), 6.4 +/- 2.7 years after Mustard's operation. Comparisons were made between rest and peak exercise. The mean resting ejection fraction was 44 +/- 12% (range 30-75%) and was unchanged at peak exercise. Eight children had a normal ejection fraction response, whereas 11 children had either no increase or a decrease in ejection fraction. Relative end-diastolic volumes decreased from resting values in all patients who had an abnormal ejection fraction response. Among patients whose ejection fraction increased, the end-diastolic volume increased in three, decreased in four and was unchanged in one at peak exercise. Heart rate increased 84% (range 52-135%) and systolic blood pressure increased 16% (range 0-28%) at peak exercise. There was no correlation between exercise response and age at surgery or interval since surgery. These data indicate that clinically well children after Mustard's procedure may have abnormal right ventricular function under stress, raising concerns about the ability of the right ventricle to function as the systemic ventricle.

Vasodilator therapy in refractory congestive heart failure: a comparative analysis of hemodynamic and noninvasive studies

The response to vasodilator therapy was assessed in 12 patients with chronic severe congestive heart failure refractory to conventional treatment. Cardiac output and intraarterial and pulmonary capillary wedge pressures were recorded continuously to assess the hemodynamic response to the vasodilators used. Control and post-treatment M mode echocardiograms and radionuclide angiograms were obtained to assess the change in left ventricular size and ejection fraction concurrent with the hemodynamic improvement. Despite a 33 percent decrease in pulmonary capillary wedge pressure (p less than 0.001) and a 35 percent increase in cardiac index (p less than 0.001), no significant change occurred in left ventricular end-diastolic or end-systolic chamber size on echocardiography or in ejection fraction measured with radionuclide angiography. In this study M mode echocardiography and radionuclide angiography were of no value in monitoring the actual hemodynamic response to vasodilator therapy in this group of patients with a left ventricular ejection fraction of less than 30 percent.