Evaluation of horn bud wound healing following cautery disbudding of preweaned dairy calves treated with aluminum-based aerosol bandage.

Pain management during and following disbudding procedures has been studied extensively, though few studies have evaluated wound healing following cautery disbudding in dairy calves. The purpose of this study was to observe wound healing following cautery disbudding with or without treatment using a topical aluminum-based aerosol bandage (ALU) in preweaned dairy calves. Dairy calves were disbudded within the first 3 wk of life using a standard cautery disbudding protocol. The ALU treatment was randomly allocated to the right or left horn bud within each animal. The outcomes measured were lesion score (LS) and wound diameter (WD). The LS was evaluated on a scale of 1 to 3, with LS = 1 representing normal healing without a scab or exudate, LS = 2 having the presence of a scab, and LS = 3 showing the presence of wound exudate. Lesion score and WD were evaluated on a weekly basis following dehorning for 3 wk. A total of 209 animals completed the study. No difference was observed in LS between groups during the first 2 wk postdisbudding, but the proportion of LS = 3 on wk 3 postdisbudding was greater for the control group when compared with ALU (17 vs. 8%, respectively). During wk 1 and 2 postdisbudding, the odds of having delayed healing, or a LS ≥2, were similar for both groups. However, the odds tended to be different at wk 3 postdisbudding with control disbudding sites being 1.42 times more likely to have delayed healing than ALU. In wk 3, WD was 1 mm smaller in the treatment group compared with the control, and treatment decreased diameter over time compared with controls. Overall, once abnormal wound healing was observed, the likelihood of having abnormal wound healing the following week was increased. However, treatment with ALU diminished this effect on delayed healing during the follow-up period. Based on these results, the use of ALU improved wound healing following cautery disbudding of preweaned dairy calves.

Herd management practices and their association with bulk tank somatic cell count on United States dairy operations.

The objective of this study was to evaluate associations between bulk tank somatic cell count (BTSCC) and herd management practices using data collected in the National Animal Health Monitoring System Dairy 2002 study. Twenty-six percent and 17.8% of 1,013 operations reported a BTSCC < 200,000 cells/mL and > 400,000 cells/mL, respectively. Univariate analysis identified associations between management variables and BTSCC. The use of mattresses, sand, and newspaper as bedding were all associated with a lower BTSCC. Primary lactating cow housing facility, outside maternity housing area, flooring type cows walk or stand on, and use of automatic take-offs were also associated with BTSCC. Multivariate associations between management variables and BTSCC were determined by backward elimination ordinal logistic regression. The odds of an operation from the West, Midwest, and Northeast having a high BTSCC were lower than those from the Southeast. The odds of a higher BTSCC were 2 times greater for operations with a rolling herd average milk production < 9,090 kg/cow per year compared with those with > or = 9,090 kg/cow per year. Operations using composted manure were 2.9 times more likely to have a higher BTSCC than those not using composted manure. Finally, operations that reported not using a coliform mastitis vaccine were 1.7 times more likely to have a higher BTSCC than those using one. Future studies of the association between management practices and BTSCC should include an evaluation of the quality of management practice application and herd prevalence of contagious mastitis pathogens. Significant variables identified in this study dealt with housing, use of composted manure for bedding, and coliform mastitis vaccine use, suggesting the effect of environmental mastitis pathogens may be more influential on BTSCC than previously thought.

Percutaneous mitral balloon valvotomy in patients with calcific mitral stenosis: immediate and long-term outcome.

OBJECTIVES: This study analyzed the immediate and long-term outcome of percutaneous balloon mitral valvotomy in patients with and without fluoroscopically visible mitral valve calcification. BACKGROUND: Mitral valve calcification has been shown to be an important factor in determining immediate and long-term outcome of patients undergoing surgical mitral commissurotomy. Patient selection has an important impact on the outcome of percutaneous balloon mitral valvotomy. METHODS: The immediate and long-term results of percutaneous balloon mitral valvotomy were compared in 155 patients with and 173 patients without mitral valve calcification. The patients with calcified valves were assigned to four groups according to severity of calcification. RESULTS: Patients with calcified mitral stenosis more frequently were in New York Heart Association functional class III or IV and more frequently had atrial fibrillation, previous surgical commissurotomy, echocardiographic score > 8, higher pulmonary artery and left atrial pressures, higher pulmonary vascular resistance and mean mitral valve gradient and lower cardiac output and smaller mitral valve area. Mitral valve area after valvotomy was significantly smaller in patients with calcified valves (1.8 +/- 0.06 vs. 2.1 +/- 0.06 cm2) and was > or = 1.5 cm2 in 65% of patients with and 83% of patients without calcified valves (p = 0.004). A successful outcome, defined as mitral valve area > 1.5 cm2 without significant mitral regurgitation and left to right shunting, was achieved in 52% of patients with and 69% of patients without uncalcified valves (p = 0.001). The success rate was 59%, 48%, 35% and 33% in subgroups with 1+, 2+, 3+ and 4+ calcification, respectively. The rates of significant left to right shunting and mitral regurgitation after valvuloplasty were similar in the two groups. Estimated survival rate (80% vs. 99%, respectively, p = 0.0001), survival rate without mitral valve replacement (67% vs. 93%, respectively, p < 0.00005) and event-free survival rate (63% vs. 88%, respectively, p < 0.00005) at 2 years were significantly better in the patients with uncalcified valves. Survival rate curves became progressively worse as the severity of calcification increased. CONCLUSIONS: These findings indicate that immediate and long-term results of mitral valvuloplasty are not as successful in patients with fluoroscopically visible mitral valve calcification as in those without calcification.

A noninvasive radiographic technique for evaluation of exercise-induced changes in cardiac function.

An electrocardiographic-triggered radiographic technique for obtaining a single image of the heart at both end-systole and end-diastole was used in conjunction with upright bicycle exercise to detect stress-induced changes in 1) systolic and diastolic cardiac transverse diameter, and 2) regional motion of the free left ventricular wall. Twenty-one patients were studied; 10 had normal coronary arteries and 11 had significant coronary artery disease. Twenty patients (10 with normal coronary arteries and 10 with coronary artery disease) also had multigated radionuclide blood pool scans at rest and with exercise. All patients without coronary disease showed a decrease in systolic cardiac transverse diameter with exercise and a slight increase in amplitude of motion of the left ventricular free wall. Eight (73%) of the 11 patients with coronary artery disease showed an increase in systolic transverse cardiac diameter with exercise (p less than 0.001), and 5 developed either new regional left ventricular asynergy or deterioration of segments with rest asynergy. Eight of the 10 patients with coronary artery disease who had rest and exercise radionuclide scans had an abnormal ejection fraction response to exercise. However, only 4 of the 10 control patients who had multigated scans had a normal ejection fraction response, although all showed normal regional wall motion with exercise. This new approach is inexpensive and easily performed. These preliminary data suggest that it may be a useful adjunct to cardiac stress testing and is worthy of further study.

Comparison of the echocardiographic and hemodynamic diagnosis of rheumatic tricuspid stenosis.

Two-dimensional echocardiography has proved to be reliable in the diagnosis of mitral, aortic and pulmonary stenosis. Its role in the diagnosis of rheumatic tricuspid stenosis is still being defined; therefore, the tricuspid valve echograms of 147 patients with rheumatic heart disease were examined. Thirty-eight of these patients also underwent hemodynamic evaluation. Tricuspid stenosis was defined echocardiographically as diastolic anterior leaflet doming, thickening and restricted excursion of the other two tricuspid leaflets and decreased separation of the leaflet tips. Using these criteria, the sensitivity and specificity of the echocardiogram in detecting tricuspid stenosis were 69 and 96%, respectively, in the group of 38 patients who had both echocardiographic and hemodynamic evaluations. However, when the smaller group of 17 patients who had simultaneous right atrial and right ventricular pressure recordings were considered separately, there was complete agreement between the echocardiographic and hemodynamic data. Thus, the two-dimensional echocardiogram is a sensitive and specific test for diagnosing rheumatic tricuspid stenosis. In addition, these data provided an opportunity to determine the prevalence of tricuspid stenosis in this group of patients with chronic rheumatic valvular disease. Tricuspid stenosis was present in 14 (9.5%) of the total group of 147 patients who had two-dimensional echocardiograms, and in 10 (26.3%) of the 38 who had both echocardiographic and hemodynamic studies. In patients with rheumatic heart disease about to undergo cardiac catheterization, an echocardiographic study should prove useful in making the diagnosis of tricuspid stenosis.

Quantitation of acute myocardial infarct size by nuclear magnetic resonance imaging.

Nuclear magnetic resonance (NMR) imaging has shown potential in the detection and characterization of acute myocardial infarction in humans. This study was performed to evaluate the capability of NMR imaging in the measurement of infarct size in patients with recent myocardial infarction. Electrocardiographic (ECG)-gated spin-echo NMR imaging was performed in 26 patients a mean of 9 +/- 3 days (range 5 to 20) after infarction. The imaging technique used provided single-slice, spin-echo (time to echo [TE] = 60 ms) images of the left ventricle in its true short axis, allowing direct correlation of NMR infarct location and size with the region of severe hypokinesia on left ventriculography. In all 20 patients with complete NMR studies, infarct location was correctly identified by using specific, objective criteria. The correlation between the mean infarct volume (29 +/- 11 ml) and the quantitated left ventricular hypokinetic segment (7.5 +/- 4.0 cm) was good (r = 0.84, p = 0.0002), suggesting that NMR imaging of the heart may have a role in the noninvasive assessment of myocardial infarct size in patients.

Coronary endothelial dysfunction in patients with acute-onset idiopathic dilated cardiomyopathy.

OBJECTIVES: This study sought to determine whether coronary endothelial dysfunction exists in patients with acute-onset idiopathic dilated cardiomyopathy (DCM) and to explore its relation to recovery of left ventricular systolic function in this patient population. BACKGROUND: Coronary endothelial dysfunction exists in chronic DCM, but its importance in the development and progression of ventricular dysfunction is not known. To address this issue we studied coronary endothelial function in patients with idiopathic DCM <6 months in duration and explored the relation between coronary endothelial function and subsequent changes in left ventricular ejection fraction (LVEF). METHODS: Ten patients with acute-onset idiopathic DCM (duration of heart failure symptoms 2.0 +/- 0.4 months [mean +/- SEM]) and 11 control patients with normal left ventricular function underwent assessment of coronary endothelial function during intracoronary administration of the endothelium-dependent vasodilator acetylcholine and the endothelium-independent vasodilator adenosine. Coronary cross-sectional area (CSA) was determined by quantitative coronary angiography and coronary blood flow (CBF) by the product of coronary CSA and CBF velocity measured by an intracoronary Doppler catheter. Patients with DCM underwent assessment of left ventricular function before and several months after the study. RESULTS: Acetylcholine infusion produced no change in coronary CSA in control patients but significant epicardial constriction in patients with DCM (-36 +/- 11%, p < 0.01). These changes were associated with increases in CBF in control patients (+118 +/- 49%, p < 0.01) but no change in patients with DCM. Infusion of adenosine produced increases in coronary caliber and blood flow in both groups. Follow-up assessment of left ventricular function was obtained in nine patients with DCM 7.0 +/- 1.7 months after initial study, at which time LVEF had improved by > or =0.10 in four patients. Multiple linear regression revealed a positive correlation between both the coronary CSA (r2 = 0.57, p < 0.05) and CBF (r2 = 0.68, p < 0.01) response to acetylcholine and the subsequent improvement in LVEF. CONCLUSIONS: Coronary endothelial dysfunction exists at both the microvascular and the epicardial level in patients with acute-onset idiopathic DCM. The preservation of coronary endothelial function in this population is associated with subsequent improvement in left ventricular function.

Determination of the quantitative thallium imaging variables that optimize detection of coronary artery disease.

Although quantification of exercise thallium images has been previously reported, the relative value of different imaging variables for detection of coronary artery disease has not been analyzed in a large group of patients with cardiac catheterization data. Regional initial thallium uptake, redistribution and clearance on thallium study were measured in 325 patients also undergoing cardiac catheterization (281 patients with and 44 patients without coronary artery disease). Normal values were defined in 55 other clinically normal subjects. When five myocardial segments were analyzed in each view, the respective values for sensitivity and specificity were 95 and 50% for initial thallium uptake, 60 and 87% for redistribution and 74 and 66% for clearance. Initial thallium uptake was the most sensitive but least specific (p less than 0.001), whereas redistribution was the least sensitive and most specific (p less than 0.001). Using stepwise logistic regression analysis, the best correlate of coronary artery disease was initial thallium uptake. Addition of redistribution to a mathematical model of the probability of coronary artery disease did not alter sensitivity, but increased specificity from 50 to 70% (p less than 0.001). Once initial uptake and redistribution were considered, myocardial thallium clearance provided no additional improvement in the correlation. Excluding the two basal segments in each view from the analysis increased the specificity from 70 to 80% (p less than 0.001) without affecting sensitivity. Of the 15 patients (5%) with coronary disease not detected using this approach, none had left main disease and 10 (67%) had one vessel disease. A combination of variables derived from quantification of exercise thallium images provides a superior sensitivity and specificity for the detection of coronary artery disease compared with the use of a single variable.

Noninvasive tissue characterization: diagnosis of lipomatous hypertrophy of the atrial septum by nuclear magnetic resonance imaging.

An atrial septal mass was identified by echocardiogram in a patient with multiple subcutaneous lipomas. In order to differentiate the benign condition of lipomatous hypertrophy from myxoma, thrombus and other tumors, nuclear magnetic resonance and computed tomographic imaging were performed. Both techniques identified the adipose nature of the tissue noninvasively, consistent with the diagnosis of lipomatous hypertrophy. Pathologically demonstrated lipomatous hypertrophy in a postmortem heart was similarly characterized by nuclear magnetic resonance imaging.

A multicenter, randomized study of argatroban versus heparin as adjunct to tissue plasminogen activator (TPA) in acute myocardial infarction: myocardial infarction with novastan and TPA (MINT) study.

OBJECTIVES: This study examined the effect of a small-molecule, direct thrombin inhibitor, argatroban, on reperfusion induced by tissue plasminogen activator (TPA) in patients with acute myocardial infarction (AMI). BACKGROUND: Thrombin plays a crucial role in thrombosis and thrombolysis. In vitro and in vivo studies have shown that argatroban has advantages over heparin for the inhibition of clot-bound thrombin and for the enhancement of thrombolysis with TPA. METHODS: One hundred and twenty-five patients with AMI within 6 h were randomized to heparin, low-dose argatroban or high-dose argatroban in addition to TPA. The primary end point was the rate of thrombolysis in myocardial infarction (TIMI) grade 3 flow at 90 min. RESULTS: TIMI grade 3 flow was achieved in 42.1% of heparin, 56.8% of low-dose argatroban (p = 0.20 vs. heparin) and 58.7% of high-dose argatroban patients (p = 0.13 vs. heparin). In patients presenting after 3 h, TIMI grade 3 flow was significantly more frequent in high-dose argatroban versus heparin patients: 57.1% versus 20.0% (p = 0.03 vs. heparin). Major bleeding was observed in 10.0% of heparin, and in 2.6% and 4.3% of low-dose and high-dose argatroban patients, respectively. The composite of death, recurrent myocardial infarction, cardiogenic shock or congestive heart failure, revascularization and recurrent ischemia at 30 days occurred in 37.5% of heparin, 32.0% of low-dose argatroban and 25.5% of high-dose argatroban patients (p = 0.23). CONCLUSIONS: Argatroban, as compared with heparin, appears to enhance reperfusion with TPA in patients with AMI, particularly in those patients with delayed presentation. The incidences of major bleeding and adverse clinical outcome were lower in the patients receiving argatroban.

Short communication: Efficacy of parenteral ceftiofur for treatment of systemically mild clinical mastitis in dairy cattle.

The objective of this study was to evaluate the effect of intramuscular (i.m.) ceftiofur (2.2 mg/kg) on important outcomes of systemically mild clinical mastitis episodes in lactating dairy cattle. Cows with clinical mastitis were randomly assigned to a treatment group: pirlimycin intramammary (i.m.m.) (n = 35), pirlimycin i.m.m. and ceftiofur i.m.m. (n = 36), cephapirin i.m.m. (n = 40), cephapirin i.m. and ceftiofur i.m. (n = 33). Sixty-nine, 22, and 9% of initial cultures were gram-negative, gram-positive, and mixed, respectively. Logistic regression analysis showed no significant associations between treatment groups and loss of quarter, recurrence, or culling. Mixed infections, positive milk culture at 7 d after leaving hospital pen, decreased rumen motility, and absence of udder firmness were associated with increased odds of mastitis recurrence. The results suggest that i.m. ceftiofur treatment has no beneficial effects on the outcome of systemically mild clinical mastitis.

Evaluation of ovine herpesvirus type 2 infections, as detected by competitive inhibition ELISA and polymerase chain reaction assay, in dairy cattle without clinical signs of malignant catarrhal fever.

OBJECTIVE: To monitor ovine herpesvirus type 2 (OvHV-2) infection status and the association between OvHV-2 infection and development of clinical signs of malignant catarrhal fever (MCF) in cattle. DESIGN: Longitudinal study. ANIMALS: 30 mature adult cows and 18 cattle submitted for necropsy. PROCEDURE: Blood and milk samples were collected at monthly intervals from 30 adult cows for 20 consecutive months. Nasal and ocular swab specimens were also collected during months 9 through 20. Polymerase chain reaction (PCR) assay for detection of OvHV-2 was performed on blood, milk, nasal swab, and ocular swab specimens. Competitive inhibition ELISA (CI-ELISA) for detection of antibodies against MCF viruses was performed on serum samples obtained prior to study initiation and monthly during the last 12 months. Tissues obtained from herdmates without clinical signs of MCF that were submitted for necropsy were analyzed for OvHV-2 DNA via PCR assay for possible sites of latency. RESULTS: Initially, 8 of 30 cows had positive CI-ELISA results. Seroconversion was detected in 4 cows. Ovine herpesvirus type 2 DNA was intermittently detected in blood, milk, nasal secretions, or ocular secretions from 17 of 30 cows. Twenty-one cows had positive CI-ELISA or PCR assay results. No cattle in the study developed clinical signs of MCF. Results of PCR assays performed on tissue samples from 2 of 18 animals submitted for necropsy were positive for OvHV-2. CONCLUSIONS AND CLINICAL RELEVANCE; OvHV-2 infection can occur in cattle without concurrent development of clinical MCF. Ovine herpesvirus type 2 DNA was detected intermittently, suggesting fluctuating viral DNA loads or reinfection in subclinical cattle. A definitive site of latency was not identified from tissues obtained during necropsy.

Current status of treatment of acute leukemia in adults: an overview of the Memorial experience and review of literature.

The results of treatment of 629 previously untreated adults with acute leukemia at Memorial Hospital are reviewed. During the past 14 years, 135 adults (greater than 15 years) with acute lymphoblastic leukemia (ALL) have been treated with one of three successive multidrug-intensive treatment protocols (L2, L10/10M, and L17/17M), each calling for 2.5 to 3 years of systemic chemotherapy and prophylactic intrathecal methotrexate without cranial irradiation. The complete remission (CR) rates were L2 (n = 22) = 77%; L10/10M (n = 69) = 86%; L17/17M (n = 44) = 77%. The median durations of survival and remission were, respectively, L2 = 33 and 30 months; L10/10M = 62 months and not reached; and L17/17M = not reached. Almost all relapses occurred within the first 3 years while still continuing treatment, and there were only rate late relapses after stopping treatment. It appears that approximately half of the patients may have been cured with the latest two protocols. During the last 17 years, 494 adults aged 15 to greater than 70 with acute nonlymphoblastic leukemia (ANLL) were treated with one of five successive multiple drug treatment protocols of varying intensity (arabinosylcytosine + 6-thioguanine [n = 36]; L6 [n = 101]; L12 [n = 104]; L14/14M [n = 121]; and L16/16M [n = 132]). Patients with myelodysplastic syndromes generally were not treated until they developed acute leukemia, but were then entered and included in the results. Secondary leukemias following treatment of other neoplastic diseases were not included. The complete remission rates were fairly constant between 47 and 64% and the median durations of remissions were between 9 and 21 months. The intensive treatment L14 and L16 protocols were associated with more early deaths and did not result in a significantly improved remission incidence or duration or survival. With all protocols, the majority of relapses occurred within the first 2 years, but relapses continued to occur at a decreasing rate for 4 years and occasionally even later. Whereas a small fraction (approximately 10 to 15%) of adults with ANLL are now apparently being cured with combination chemotherapy, despite intensive efforts there has been little improvement during the last decade and more selective and effective forms of treatment are urgently needed.

Hyperfractionated total body irradiation for bone marrow transplantation. Results in seventy leukemia patients with allogeneic transplants.

From May, 1979 to March, 1981, 76 leukemia patients were prepared for bone marrow transplantation (BMT) with a new hyperfractionated total body irradiation (TBI) regimen (1320 cGy in 11 fractions, 3x/day), followed by cyclophosphamide, 60 mg/kg, for two days. Partial lung shielding was done on each treatment, with supplemental electron beam treatments of the chest wall to compensate, and of the testes, a sanctuary site. This regimen was initiated to potentially reduce fatal interstitial pneumonitis as well as decrease leukemic relapse. These patients were analyzed in May, 1982, for a minimum follow-up of 14 months. Overall actuarial survival at 1 year for acute non-lymphocytic leukemia (ANLL) patients is 63%, while relapse-free survival at 1 year is 53%. For those ANLL patients who underwent BMT while in remission (first, second, and third combined), relapse-free survival is 61% at 1 year compared with 40% for those patients who had their BMT at the time of relapse (greater than or equal to 10% blasts in marrow). On the other hand, for acute lymphocytic leukemia (ALL) patients, there is no significant difference between relapse or remission patients with regard to overall survival or relapse-free survival, when relapse is defined as greater than 5% blasts in the marrow at the time of cytoreduction. Overall actuarial survival at 1 year for ALL is 61% and relapse-free survival is 45% at 1 year. Patients with ALL who had their BMT cytoreduction at the time of relapse have a survival equal to that of our remission patients, and greater than that of patients in relapse cytoreduced with a single dose as reported by others. However, patients with greater than or equal to 10% blasts have not fared as well, having only a 22% 1 year relapse-free survival compared with a 68% 1 year relapse-free survival for patients with less than 10% blasts. Fatal interstitial pneumonitis has dropped to 18% compared with 50% in our previous single-dose TBI regimen (1000 cGy), in which the same doses of cyclophosphamide were given prior to TBI. In conclusion, not only has fatal interstitial pneumonitis been reduced by hyperfractionation and partial lung blocking, but there may be a survival advantage in ALL patients in relapse, who have a survival equal to that of remission patients. This may indicate a greater cell kill with the higher dose (1320 cGy) attained with this regimen, in these patients with a higher leukemic cell burden.

Gallium-67 and magnetic resonance imaging in aortic root abscess.

Perivascular abscess in the aortic root is a serious complication of infective endocarditis and is recognized infrequently with noninvasive techniques. This report describes a patient with sepsis who was imaged with 67Ga and magnetic resonance (MR) in order to locate a site of infection. The 67Ga image showed increased activity in the substernal region. Magnetic resonance correctly detected the multilocular aortic root abscess, which had extended into the interatrial septum. The combination of the sensitive 67Ga with the high-resolution MR image provided a useful method to locate aortic root abscesses and to identify contiguous spread.

Effects of coronary bypass grafting on resting left ventricular contraction in patients studied 1 to 2 years after operation.

Left ventricular contraction was evaluated with angiography in 51 patients 1 to 2 years after coronary arterial bypass surgery. The left ventricle was classified into five segments, and segmental ventricular wall motion was analyzed with subjective and objective methods. With subjective analysis, 25 percent of asynergic segments showed improvement, 72 percent no change and 3 percent deterioration in contraction. There was a 5 percent incidence rate of new wall motion abnormalities in segments that were judged normal from the preoperative ventriculogram. Objective analysis revealed significant improvement in contraction of asynergic segments in each of the five left ventricular segments analyzed. Thus, 1 to 2 years after coronary bypass surgery, there was a significant reduction in left ventricular segmental wall motion abnormalities, and the incidence of deterioration in contraction was small.

Definition of cardiac structures using computerized tomography in isolated arrested and beating canine hearts.

Computerized axial tomography of the brain is a revolutionary noninvasive technique that has provided remarkable resolution of intracerebral structures. This study was undertaken to determine the potential of computerized tomography for defining the anatomy of 40 arrested and 9 beating (ejecting left heart preparation) canine hearts. Using an EMI cranial unit, scanning was performed in hearts under in vitro conditions with a lactated Ringer's interface. The tomographic scans obtained were later compared with comparable 8 mm thick sections of the heart. At physiologic levels of hematocrit (range 36 to 45%) external structures were well defined, but because of the lack of a differential between cavitary and myocardial densities, it was not possible to distinguish intracardiac structures. With very small amounts of iodinated contrast material (remotely administered in the case of the beating hearts) or with anemia (hematocrit less than 33%), the right and left ventricular cavities became clearly visible in both horizontal and longitudinal tomographic scans. It was possible to distinguish readily the boundaries of the ventricular and atrial cavities, the papillary muscles, the major trabeculae and the aorta. Rhythmic motion of the beating heart, suspended in its pericardium, did not eliminate structural definition. Thus, computerized tomography provides a new approach to the definition of cardiac structure with a relatively high degree of resolution. These observations point to the potential usefulness of this noninvasive technique for the evluation of both cardiac function and ventricular wall abnormalities.

Assessment of drug intervention on the ischemic myocardium: serial imaging and measurement with computerized tomography.

Computerized tomography was evaluated as a technique for imaging and measuring the effect of an intervention on acutely ischemic myocardium. Because cell edema occurs with acute myocardial ischemia and decreases the X-ray attenuation coefficients (tissue density) of myocardium, computerized tomographic images were used to quantitate the effect of hyperosmotic mannitol on ischemia-induced edema. Canine hearts were arrested and scanned after (1) temporary occlusion of the proximal circumflex artery followed by reflow of blood, or (2) continued occlusion of the distal left anterior descending coronary artery. X-ray attenuation values (Hounsfield units) were linearly related to tissue wet/dry weight ratios (r = 0.87, P less than 0.001). After 2 hours of occlusion of the left anterior descending coronary artery the hearts that received mannitol manifested a significant reduction (P less than 0.05) in the volume of left ventricular wall involved with edema. Although the area of edema measured with computerized tomography tended to be smaller in the hearts treated with mannitol than in untreated hearts subjected to a 6 hour occlusion of the left anterior descending coronary artery, the size of the lesion was variable and did not differ significantly from that in untreated hearts. With either short periods of circumflex arterial occlusion followed by blood reflow or with 2 or 6 hours of prolonged occlusion of the left anterior descending coronary artery, the difference in mean attenuation coefficients between the ischemic and nonischemic areas of myocardium in mannitol-treated and untreated hearts was significantly less. These results indicate that computerized tomography in the arrested heart can detect and quantitate the lesion of early acute myocardial ischemia and can quantitate the effect of drug intervention.

Angiotensin-converting enzyme inhibition as antiatherosclerotic therapy: no answer yet. QUIET Investigators. QUinapril Ischemic Event Trial.

Angiotensin-converting enzyme inhibitors have proven to be of clinical benefit in congestive heart failure. Whether they also provide benefit to patients with coronary artery disease in the absence of congestive heart failure via an antiatherosclerotic mechanism is a question the QUinapril Ischemic Event Trial quantitative coronary angiography (QCA) study attempted to answer: 1,750 patients with normal left ventricular function who were undergoing coronary angiography and angioplasty were randomized to 20 mg/day of quinapril versus placebo and followed for 3 years for cardiac end points. A randomly selected subgroup of the total cohort underwent follow-up angiography. The primary QCA end point was the categorical designation of progression versus nonprogression, defined either by QCA or by a cardiac event in patients selected for the QCA trial who had no usable follow-up x-ray film. Secondary end points in patients with 2 angiograms were: new stenosis development, change in minimum lumen diameter index, and change in percent diameter stenosis index. There were 119 progressors among 243 placebo-treated patients (49%) and 111 progressors among 234 quinapril-treated patients (47%) (p = NS). There were 44 patients with new stenosis development in the placebo group (19%) and 50 (22%) in the quinapril group (p = NS). Change in minimum lumen diameter index was -0.21+/-0.03 mm in the placebo group and -0.18+/-0.03 mm in the quinapril group (p = NS). Finally, change in percent diameter stenosis index was +5.1+/-1.0 in the placebo group and +3.5+/-1.0 in the quinapril group (p = NS). Potential confounders of this trial are presented and discussed.

Right ventricular infarction. Clinical diagnosis and differentiation from cardiac tamponade and pericardial constriction.

Twelve patients with a clinical diagnosis of right ventricular infarction are described. All had acute inferior wall myocardial infarction associated with the bedside findings of jugular venous distension, clear lungs on auscultation, and arterial hypotension. Hemodynamically, there was elevation of right-sided filling pressures not explained by normal or minimally elevated pulmonary wedge pressures. Four patients had an incorrect diagnosis of acute cardiac tamponade. However, a review of the data showed that the hemodynamic features of right ventricular infarction more closely resemble those of pericardial constriction, a point that may be helpful in distinguishing right ventricular infarction from cardiac tamponade. Invasive and noninvasive techniques that exclude the presence of pericardial fluid and suggest enlargement and abnormal contractility of the right ventricle were helpful in establishing the diagnosis of right ventricular infarction in several patients.