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Many researchers around the world have made extensive efforts to study the phenomenon of fiber-reinforced polymer (FRP) debonding. Based on these efforts, code provisions and various models have been proposed for predicting intermediate crack (IC) debonding failure. The paper presents a comparison of seven selected models: fib bulletin 14 approach, Teng et al. model, Lu model, Seracino et al. model, Said and Wu model, Elsanadedy et al. model and ACI 440. The accuracy of each model was evaluated based on the test results of 58 flexural specimens with IC debonding failures of externally bonded (EB), carbon FRP plates or sheets found in the existing literature. The experimental database was prepared to include a wide range of parameters affecting the issue under consideration. A comparison of the measured and predicted load capacity values was made to evaluate the prediction accuracy of the considered models. The analysis included the limitation of the load capacity estimated based on IC debonding models as well as concrete crushing and FRP rupture types of failure. The results indicate that the latest models proposed for direct implementation in design guidelines-the Said and Wu model and the Elsanadedy et al. model-offer the best accuracy in predicting the load capacity. In contrast, the fib bulletin 14 approach shows a wide dispersion of predictions and a large proportion of highly overestimated results.

The P-glycoprotein (Pgp) transporter plays a central role in drug disposition by effluxing a chemically diverse range of drugs from cells through conformational changes and ATP hydrolysis. A number of drugs are known to activate ATP hydrolysis of Pgp, but coupling between ATP and drug binding is not well understood. The cardiovascular drug verapamil is one of the most widely studied Pgp substrates and therefore, represents an ideal drug to investigate the drug-induced ATPase activation of Pgp. As previously noted, verapamil-induced Pgp-mediated ATP hydrolysis kinetics was biphasic at saturating ATP concentrations. However, at subsaturating ATP concentrations, verapamil-induced ATPase activation kinetics became monophasic. To further understand this switch in kinetic behavior, the Pgp-coupled ATPase activity kinetics was checked with a panel of verapamil and ATP concentrations and fit with the substrate inhibition equation and the kinetic fitting software COPASI. The fits suggested that cooperativity between ATP and verapamil switched between low and high verapamil concentration. Fluorescence spectroscopy of Pgp revealed that cooperativity between verapamil and a non-hydrolyzable ATP analog leads to distinct global conformational changes of Pgp. NMR of Pgp reconstituted in liposomes showed that cooperativity between verapamil and the non-hydrolyzable ATP analog modulate each other's interactions. This information was used to produce a conformationally-gated model of drug-induced activation of Pgp-mediated ATP hydrolysis., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Drug-drug interactions (DDIs) and associated toxicity from cardiovascular drugs represents a major problem for effective co-administration of cardiovascular therapeutics. A significant amount of drug toxicity from DDIs occurs because of drug interactions and multiple cardiovascular drug binding to the efflux transporter P-glycoprotein (Pgp), which is particularly problematic for cardiovascular drugs because of their relatively low therapeutic indexes. The calcium channel antagonist, verapamil and the cardiac glycoside, digoxin, exhibit DDIs with Pgp through non-competitive inhibition of digoxin transport, which leads to elevated digoxin plasma concentrations and digoxin toxicity. In the present study, verapamil-induced ATPase activation kinetics were biphasic implying at least two verapamil-binding sites on Pgp, whereas monophasic digoxin activation of Pgp-coupled ATPase kinetics suggested a single digoxin-binding site. Using intrinsic protein fluorescence and the saturation transfer double difference (STDD) NMR techniques to probe drug-Pgp interactions, verapamil was found to have little effect on digoxin-Pgp interactions at low concentrations of verapamil, which is consistent with simultaneous binding of the drugs and non-competitive inhibition. Higher concentrations of verapamil caused significant disruption of digoxin-Pgp interactions that suggested overlapping and competing drug-binding sites. These interactions correlated to drug-induced conformational changes deduced from acrylamide quenching of Pgp tryptophan fluorescence. Also, Pgp-coupled ATPase activity kinetics measured with a range of verapamil and digoxin concentrations fit well to a DDI model encompassing non-competitive and competitive inhibition of digoxin by verapamil. The results and previous transport studies were combined into a comprehensive model of verapamil-digoxin DDIs encompassing drug binding, ATP hydrolysis, transport and conformational changes., (© 2016 Authors.)

Background: To have uniform criteria for evaluating populations for prevalence of transient ischemic attack (TIA)/stroke, validated instruments are necessary for objective assessment and classification., Methods: Patient responses compatible with symptoms of TIA or ischemic stroke, obtained from participants in a substudy of the Asymptomatic Carotid Atherosclerosis Study, were used to program a neural network for each symptom. Models were designed for rapid classification into 1 of 7 outputs: no event, TIA, or stroke (in left carotid, right carotid, or vertebrobasilar). The networks were then tested by comparing decisions with a validated questionnaire used to access an independent data set of 381 patients., Results: There were 144 patients who reported sudden speech change, 89 with sudden vision loss, 67 with double vision, 189 with sudden numbness, 223 with episodic dizziness, and 108 with paralysis, for a total of 820 reported symptoms among the 381 patients tested. For each category, an equal number of individuals reporting "No" to these phenomena were randomly selected and analyzed. Neural network classification correlated with the diagnoses made by specially trained stroke clinicians (e.g., all who responded "No" were correctly classified as having no neurologic event). Ten symptomatic patients were misclassified, with the most common reason being incomplete data. After adjustment of the network logic, these misclassifications did not recur., Conclusion: Computer networks can be trained to produce a rapid and accurate classification of TIA or stroke by vascular distribution, enabling screening of populations for assessment of their incidence and prevalence.

Background: Lower extremity arterial disease (LEAD) is one of the most common manifestations of atherosclerosis. Its epidemiologic characteristics have not been well described, particularly in African Americans. Our purpose was to estimate the prevalence of LEAD and its associations with cardiovascular risk factors in a biracial population of men and women aged 45 to 64 years., Methods: We examined 15,173 African-American and white men and women who participated in the baseline examination (1987-1989) of the Atherosclerosis Risk in Communities (ARIC) Study. LEAD was defined by a resting ankle-brachial index (ABI), the ratio of ankle systolic blood pressure to brachial systolic pressure, of < or = 0.90. Cross-sectional analyses were used to determine the association of LEAD with cardiovascular risk factors., Results: The age-adjusted prevalence of ABI < or = 0.90 was 3.1% in African-American men, 4.4% in African-American women, 2.3% in white men, and 3.2% in white women. Cigarette smoking was the single most important risk factor for prevalent LEAD. The odds ratio estimate for LEAD in ever smokers versus never smokers was 6.6 (95% confidence interval [CI]=2.0-21.5) in African-American men, 2.3 (95% CI=1.5-3.5) in African-American women, 10.4 (95% CI=3.8-28.3) in white men, and 1.9 (95% CI=1.4-2.6) in white women, after adjustment for age, LDL cholesterol, hypertension, and diabetes. Prevalent LEAD was also associated with hypertension, diabetes, and higher concentrations of total cholesterol, triglycerides, LDL-cholesterol, and fibrinogen, and lower concentrations of HDL cholesterol, but the associations were not always significant across race/ethnic and gender groups. The associations of LEAD with plasma lipids were generally stronger in African Americans than whites., Conclusions: The prevalence of LEAD appears to be higher in African Americans than whites. Elevations in traditional cardiovascular risk factors are associated with a higher prevalence of LEAD across race/ethnic and gender groups.

Newer, minimally invasive catheter-based endovascular technology utilizing stent grafts are currently being evaluated for abdominal aortic aneurysm (AAA) repair. A retrospective review of all (3 years) consecutive, non-ruptured elective AAA repairs was undertaken to document the results of AAA surgical repair in a modern cohort of patients to allow a contemporary comparison with the evolving endoluminal data. One hundred twenty-one AAAs were identified in a male veteran population. Mean age was 68.5 +/-7.7 years. Medical history review showed hypertension in 55%, heart disease in 73.5%, peripheral vascular disease in 21%, stroke and transient ischemic attacks in 22%, diabetes mellitus in 7%, renal insufficiency in 10%, and smoking history in 80%. The AAA size was documented with ultrasound (5.2 +/-1.3 cm, n=40) and computed tomography (5.6 +/-1.3 cm, n=100). Fifty-nine percent had angiography. Intraoperative end points included an operative time of 165 +/-6.3 minutes from incision to dressing placement. A Dacron tube graft was used in 78%, the remaining were Dacron bifurcated grafts. A suprarenal clamp was used in 8% for proximal aortic control with juxtarenal aneurysms. A pulmonary-artery catheter was placed in 69%. A transverse incision was used in 69% of patients and a midline incision was used in the rest. Estimated blood loss was 1505 +/-103 mL; cell saver blood returned 754 +/-53 mL; crystalloid/Hespan 4771 +/-176 mL; banked packed red blood cells 0.75 +/-0.11 U. Time to extubation was, in the operating room (78.5%), on the day of the operation (5.0%), postoperative day (POD) 1 (12.4%), POD2 (1.7%), POD3 (0.8%), and one case was performed with epidural anesthesia only. Postoperative end points included a 30-day mortality rate of 1.6% (two patients). Postoperative morbidity included wound dehiscence 0.8%; sepsis, urinary tract infection, wound infection, leg ischemia, ischemic colitis, and stroke each had an incidence of 1.6%; myocardial infarction, congestive heart failure, pneumonia, re-operation for suspected bleeding, and ileus or bowel obstruction occurred with an incidence of 3.3%. No significant increase in serum creatinine levels was noted. Time to enteral fluids/nutrition was 3.5 +/-0.08 days. Patients were out of bed to a chair or walking by 1.3 +/-0.06 days postoperatively. The length of stay in the intensive care unit (ICU) was 2.0 +/-0.12 days and postoperative hospital stay was 6.6 +/- 0.33 days. Transfusion requirement for the hospital stay was 1.6 +/-0.2 U per patient. This review highlights a cohort of male veteran patients with significant cardiac co-morbidity who have undergone repair with a conventional open technique and low mortality and morbidity rates. This group had rapid extubation, time to oral intake, and ambulation. In addition, ICU and hospital stays were relatively short.

Background and Purpose: This study reports the surgical results in those patients who underwent carotid endarterectomy in the North American Symptomatic Carotid Endarterectomy Trial (NASCET)., Methods: The rates of perioperative stroke and death at 30 days and the final assessment of stroke severity at 90 days were calculated. Regression modeling was used to identify variables that increased or decreased perioperative risk. Nonoutcome surgical complications were summarized. The durability of carotid endarterectomy was examined., Results: In 1415 patients there were 92 perioperative outcome events, for an overall rate of 6.5%. At 30 days the results were as follows: death, 1.1%; disabling stroke, 1.8%; and nondisabling stroke, 3.7%. At 90 days, because of improvement in the neurological status of patients judged to have been disabled at 30 days, the results were as follows: death, 1.1%; disabling stroke, 0.9%; and nondisabling stroke, 4.5%. Thirty events occurred intraoperatively; 62 were delayed. Most strokes resulted from thromboembolism. Five baseline variables were predictive of increased surgical risk: hemispheric versus retinal transient ischemic attack as the qualifying event, left-sided procedure, contralateral carotid occlusion, ipsilateral ischemic lesion on CT scan, and irregular or ulcerated ipsilateral plaque. History of coronary artery disease with prior cardiac procedure was associated with reduced risk. The risk of perioperative wound complications was 9.3%, and that of cranial nerve injuries was 8.6%; most were of mild severity. At 8 years, the risk of disabling ipsilateral stroke was 5.7%, and that of any ipsilateral stroke was 17.1%., Conclusions: The overall rate of perioperative stroke and death was 6.5%, but the rate of permanently disabling stroke and death was only 2.0%. Other surgical complications were rarely clinically important. Carotid endarterectomy is a durable procedure.

Objective: To compare the modified Rossetti fundoplication with the classic Nissen., Summary Background Data: The traditional surgical treatment of gastroesophageal reflux in children has been the classic Nissen fundoplication, defined by liver mobilization, crural repair, takedown of short gastric vessels, and floppy wrap. The authors have progressed in our technique of fundoplication and now perform a modified Rossetti fundoplication, defined by liver retraction without mobilization, no crural repair, short gastric vessels left intact, and 2-cm floppy wrap., Methods: A retrospective chart review was performed on 407 pediatric patients who had open fundoplications (Jan. 13, 1993, to Feb. 25, 1998). Two groups were analyzed: the Nissen group (171 patients) and the Rossetti group (236 patients). Groups were compared for incidence of recurrent reflux, dysphagia, hiatal hernia, need for esophageal dilation, revision of fundoplication, time to discharge, and operative time., Results: Incidence of dysphagia (3.7% vs. 3.3%), postoperative hiatal hernia (1.9% vs. 1.4%), need for esophageal dilation (1.2% vs. 0.5%), and need for fundoplication revision (2.5% vs. 2.3%) were similar between the groups. The mean operative time was significantly decreased in the Rossetti group (65 +/- 25 minutes) versus the Nissen group (73 +/- 33 minutes). Recurrent reflux occurred significantly more often in the Nissen group (11.2%) than in the Rossetti group (5.1 %)., Conclusion: The modified Rossetti fundoplication has a low complication rate and is the authors' preferred method for the surgical treatment of gastroesophageal reflux in children.

Vascular surgery has matured as a subspecialty of general surgery during the past 25 years. The discipline currently faces a number of challenges including duration and scope of training, financing of graduate medical education, specialty and subspecialty certification, hospital privileging or credentialing, and practice opportunities. This article reviews these issues in terms of present realities and future opportunities. Emphasis is placed on curricular redesign to tailor length and breadth of training to future career goals, be they private practice as a general surgeon with vascular surgery interests, a vascular surgical subspecialist, a rural versus an urban practice, or a subspecialist in an academic setting. A plea is made for regulatory bodies, including the Residency Review Committee for Surgery and the American Board of Surgery, as well as specialty societies, particularly the American College of Surgeons, to maintain a flexible and constructive posture in dealing with proposed educational innovations. With cooperative efforts of both the Association of Program Directors in Surgery and the Association of Program Directors in Vascular Surgery, vascular surgery education and training of both general surgeons and vascular surgeons should be enhanced to fulfill the workforce needs as we enter the next millennium.

Cardiac autonomic activity, as assessed by heart rate variability, has been found to be associated with postmyocardial infarction mortality, sudden death, and all-cause mortality. However, the association of heart rate variability and the incidence of coronary heart disease (CHD) is not well described. The authors report on the association of baseline cardiac autonomic activity (1987-1989) with incident CHD after 3 years (1990-1992) of follow-up of the Atherosclerosis Risk in Communities Study cohort selected from four study centers in the United States by using a case-cohort design. The authors examined 137 incident cases of CHD and a stratified random sample of 2,252 examinees free of CHD at baseline. Baseline, supine, resting beat-to-beat heart rate data were collected. High- (0.16-0.35 Hz) and low- (0.025-0.15 Hz) frequency spectral powers and high-/low-frequency power ratio, estimated from spectral analysis, and standard deviation of all normal R-R intervals, calculated from time domain analysis, were used as the conventional indices of cardiac parasympathetic, sympatho-parasympathetic, and their balance, respectively. Incident CHD was defined as hospitalized myocardial infarction, fatal CHD, or cardiac revascularization procedures during 3 years of follow-up. The age, race, gender, and other CHD risk factor-adjusted relative risks (and 95% confidence intervals) of incident CHD comparing the lowest quartile with the upper three quartiles of high-frequency power, low-frequency power, high-/low-frequency power ratio, and standard deviation of R-R intervals were 1.72 (95% confidence interval (CI) 1.17-2.51), 1.09 (95% CI 0.72-1.64), 1.25 (95% CI 0.84-1.86), and 1.39 (95% CI 0.94-2.04), respectively. The findings from this population-based, prospective study suggest that altered cardiac autonomic activity, especially lower parasympathetic activity, is associated with the risk of developing CHD.

The Atherosclerosis Risk in Communities (ARIC) study is a prospective investigation of the etiology and natural history of atherosclerosis and cardiovascular disease in four U.S. communities. The purpose of this work is to investigate the relationship between common carotid artery elasticity and intimal-medial thickness (IMT) in the four race-gender groups represented in the ARIC cohort. Noninvasive ultrasonic methods were used to measure IMT and the [systolic minus diastolic] diameter change (DC) of the left common carotid artery in 10,920 black and white, men and women between the ages of 45 and 64 y. The relationship between DC and IMT and IMT2 was examined after adjustment of DC for age, height, diastolic diameter, diastolic blood pressure and linear and quadratic terms for pulse pressure. This adjusted value of DC was used as an index of elasticity of the common carotid artery in the ARIC cohort with larger values of adjusted DC implying a more elastic vessel. The general behavior of adjusted DC with increasing IMT was observed to be qualitatively similar in all four race-gender groups. Adjusted DC remained nearly constant or increased slightly for values of IMT between approximately 0.4 and 0.8 mm, up to approximately the 90th percentile of IMT, and then decreased above the 90th percentile of IMT. Common carotid artery elasticity, defined as adjusted DC, varies with increasing IMT in the ARIC cohort in a manner consistent with results from previous studies in animals and human subjects addressing the variation of several elasticity indices with atherosclerotic involvement and risk factor exposure in the aorta, and brachial and radial arteries. Our results suggest that thicker common carotid artery walls in middle-aged U.S. populations are no stiffer than thinner walls, except for the thickest 10% of arteries. Since the distal common carotid artery frequently contains atheromatous plaques in this population, the lack of change in stiffness, indeed, the reduction in stiffness per unit thickness, may reflect the various stages of early common carotid atherosclerosis most often found in this population. These are characterized more by destruction of arterial wall structural elements than by changes such as widespread or circumferential sclerosis, which would strengthen and stiffen the artery.

To relate cardiac autonomic function measured by heart rate variability (HRV) with prevalent and incident hypertension at the population level, the authors examined a stratified random sample of 2,061 examinees from the biracial Atherosclerosis Risk in Communities (ARIC) cohort. Baseline, supine, resting beat-to-beat heart rate data were collected. High frequency (HF, 0.15 to 0.35 Hz), low frequency (LF, 0.025 to 0.15 Hz) spectral powers, and LF/HF ratio, estimated from spectral analysis, and standard deviation of all normal RR intervals (SDNN), calculated from time domain analysis, were used as the conventional indices of cardiac autonomic function. From this sample, 650 prevalent hypertensives were identified. Of those normotensive at baseline (n = 1,338), 64 participants developed hypertension during 3 years of follow-up. In the cross-sectional analysis, the adjusted geometric means of HF were 1.26, 1.20, and 1.00 (beat/min)2 for normotensives, untreated hypertensives, and treated hypertensives, respectively; means of LF were 3.24, 3.26, and 2.58; means of LF/HF ratio were 2.57, 2.70, and 2.56; and means of SDNN were 39, 34, and 35 (ms) respectively. In the prospective analysis, a statistically significant, graded inverse association between baseline HF and the risk of incident hypertension was observed: the adjusted incident odds ratios (95% CI) were 1.00, 1.46 (0.61, 3.46), 1.50 (0.65, 3.50) and 2.44 (1.15, 5.20) from the highest to the lowest quartile of HF. No clear pattern of association was observed for LF. Significant trends of association for LF/HF and SDNN and incident hypertension were also found. These results suggest that cardiac autonomic function is associated with prevalent hypertension, and that reduced vagal function and the imbalance of sympatho-vagal function are associated with the risk of developing hypertension.

Objective: The opinions of general surgery program directors (SPDs) and vascular surgery program directors (VPDs) regarding vascular surgery training of general surgery residents and the construct of the vascular surgery residency were compared., Methods: Questionnaires were mailed to 55 VPDs and 290 SPDs in 1987 and 1988, and to 80 VPDs and 277 SPDs in 1995. Both questionnaires included questions regarding attitudes about vascular surgical competence, operative experience, future vascular practice opportunities of general surgery residents, and the impact of a vascular surgery residency on general surgery resident education. In addition, the 1995 survey included questions regarding the duration, content, and prerequisite versus requisite experience for the vascular surgery residency., Results: Significant differences in opinions between SPDs and VPDs persisted regarding vascular surgery training of general surgery residents. SPDs were more likely to feel that general surgery graduates are fully competent in vascular surgery, should be exposed to more complex vascular surgery during training, and should be granted unlimited vascular surgical privileges on entering practice. Most VPDs felt that general surgery graduates lack competence in vascular surgery, should be exposed to less complex vascular surgery during training, and should have limited vascular surgery privileges in practice. Both groups of program directors agreed about the construct of vascular surgery residencies and that such residencies have had a favorable impact on general surgery resident education. Both SPDs and VPDs were willing to consider creative restructuring of vascular surgery residencies to accommodate governmental restrictions on funding of graduate medical education., Conclusions: External pressures forcing residency reform may provide an opportunity for SPDs and VPDs to creatively work with regulatory bodies to resolve differences in expectations of vascular surgery education and practice.

We identified a group of 24 young (less than 50 years of age) women with isolated, premature atherosclerotic aortoiliac occlusive disease and attempted to identify distinguishing hemostatic characteristics. Most of these patients (62%) presented with acute thromboembolic events (blue toe syndrome, n = 6; macroemboli, n = 6; or aortoiliac thrombosis, n = 3). Aortoiliac reconstruction (aortoiliac endarterectomy, n = 10, aortobifurcation bypass grafts, n = 6; and percutaneous angioplasty, n = 4) was complicated by early thrombosis in 6 of 20 cases (30%), (1 of 10 endarterectomies, 4 of 6 bypass grafts, and 1 of 4 angioplasties). Fresh thrombus overlying an atherosclerotic plaque was a common finding at surgery. This observation and the relatively high incidence of thromboembolic events led us to hypothesize that a characteristic hemostatic profile might underlie the remarkably similar clinical presentations of these women. Levels of antiphospholipid antibodies (anticardiolipin antibodies and lupus anticoagulant), plasminogen activator inhibitor-1, fibrinogen, antithrombin III, protein C, protein S, plasminogen, prothrombin fragment F1 + 2, and D-dimer were determined for these young women and for 21 age-matched white female control subjects without vascular disease and nine white male patients with aortoiliac occlusive disease (mean 61 years, range 43 to 74 years). The incidence of anticardiolipin antibodies was 42% (8 of 19) in the female patients, which was significantly elevated (p = 0.028). The female (62.5%) and male (100%) patients had significantly elevated D-dimer levels (p < 0.001). Deficiencies of antithrombin III, protein C, and protein S were rare. A unique pattern of premature aortoiliac atherosclerosis exists in some young women. Intra-arterial thromboembolic events are common at presentation and complicate surgical management. The role of antiphospholipid antibodies remains uncertain.

Purpose: The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Asymptomatic Carotid Artery Study (ACAS) both confirmed the effectiveness of carotid endarterectomy for preventing stroke in patients who have significant carotid stenosis. A uniform technique for measuring carotid stenosis from an arteriogram (% stenosis = [1 - minimum residual lumen/normal distal cervical internal carotid artery diameter] x 100) was used in both trials, with reproducibility internally validated. The reliability of this measurement when used outside the trials for defining carotid stenosis has not been validated. Imprecise calculation of carotid stenosis can result in a 50% overestimation of significant carotid disease and potential overuse of carotid surgery. This is a prospective study of the reliability of carotid stenosis measurements performed by practicing physicians of different specialties and different levels of clinical experience., Methods: Two vascular surgeons and two interventional radiologists (one resident and one staff member per specialty), blinded to results, calculated the percent stenosis from 219 consecutive arteriograms performed to evaluate extracranial carotid artery occlusive disease; 72 random films were reread by each individual. The interpretations were grouped as < 60% or > or = 60% stenosis (ACAS) and as < 30%, 30% to 69%, and > or = 70% stenosis (NASCET). Interobserver and intraobserver agreement were analyzed with the kappa statistic and Pearson correlation coefficients., Results: Interobserver reliability in categorizing carotid stenosis revealed excellent agreement for both ACAS (kappa = 0.825 to 0.903) and NASCET groups (kappa = 0.729 to 0.793). Interobserver correlation coefficients ranged from 0.91 to 0.95. Intraobserver agreement was also highly reproducible for both the ACAS (kappa = 0.732 to 0.970) and NASCET categories (kappa = 0.634 to 0.805). Intraobserver correlation coefficients ranged from 0.89 to 0.95., Conclusion: The NASCET technique for quantification of carotid stenosis can be easily learned by physicians and reliably implemented for appropriate identification of candidates for carotid endarterectomy.

An endarterectomized segment of an occluded artery (e.g. superficial femoral artery), is an alternative autogenous material for patch angioplasty which preserves the continuity of the saphenous vein. A technique of incising endarterectomized segments of superficial femoral artery in a spiraled manner is presented which allows for the creation of long autogenous tissue patches. A spiral is drawn on the exterior of a harvested arterial segment which is either 1 cm, 7 mm or 5 mm in width. When incised along the spiral, the length of the resulting elliptical patch will be two, three, or four times, respectively, the length of the original artery segment. The authors have used the technique to close extended profundoplasty in three patients and for construction of a patched distal anastomosis in two patients undergoing prosthetic femoropopliteal bypass grafting. There have been no early complications.

Clinically based studies have indicated that patients who have suffered myocardial infarction (MI) exhibit lower heart rate variability (HRV). Such associations have not been reported at the population level. To investigate whether MI is related to lower HRV in the general population, the authors examined a stratified random sample of 2,243 men and women aged 45-64 years, of whom 260 had had MI and 1,983 were free of any coronary heart disease manifestations. All were part of the biracial cohort of the Atherosclerosis Risk in Communities study sampled from four United States communities. Resting, 2-minute supine heart rate data were analyzed using spectral analysis to estimate high-frequency (0.16-0.35 Hz) and low-frequency (0.025-0.15 Hz) spectral powers as conventional indices of HRV. The mean levels of high-frequency powers were 1.02 and 1.23 (beats/min)2 for MI and non-MI groups, respectively (P < .05), and the low-frequency means were 2.46 and 3.11 (beats/min)2 for MI and non-MI groups, respectively (P < .01). Age, race, and sex-adjusted odds ratios (95% confidence interval) of lower high-frequency and low-frequency powers contrasting MI to non-MI individuals were 1.52 (range, 1.09-2.10) and 1.54 (range, 1.12-2.10), respectively. After adjustment for use of beta-blocker medication, the odds ratios (95% confidence interval) were 1.26 (range, 0.88-1.81) and 1.22 (range, 0.87-1.69) for lower high-frequency and low-frequency powers, respectively. The findings from this first population-based study of prevalent MI and HRV provide support for an inverse association between MI and lower HRV. However, adjusting for beta-blocker use eliminates the statistical association. These findings confirm that impaired HRV is found in individuals with prevalent MI, even when drawn as a sample of community-dwelling individuals. This impaired HRV may contribute to the increased risk of subsequent cardiovascular events previously observed in survivors of acute MI. The cross-sectional data also suggest that use of beta-blockers diminishes the odds of lower HRV associated with MI.

A 53-year-old woman, 11 years after a renal transplant on chronic immunosuppression, presented with a sudden onset of a painless left groin mass. Ultrasound revealed a 3 cm common femoral artery pseudoaneurysm and a 3 cm saccular aneurysm of the infrarenal aorta. Operative repair was excision and patch angioplasty of the aortic aneurysm with internal iliac artery and interposition grafting of the femoral artery aneurysm with saphenous vein. Postoperatively, Candida albicans was identified in the aortic and common femoral arterial cultures. Candida infections often occur in patients with impaired cellular immunity due to seeding from urinary tract infections, vascular catheters, or manipulation of the gastrointestinal tract. Our patient, without any prior history of a fungal infection, had undergone a colonoscopy 3 weeks earlier. Without any other possible source being identified, the proposed mechanism for fungal entry into the vascular system was via the gastrointestinal tract, with seeding from the portal venous system. The exact medical and surgical management of these patients remains undefined, and a transplant vascular registry is really needed. However, immunocompromised solid organ transplant recipients undergoing gastrointestinal endoscopic procedures may be at a greater risk for the development of subsequent septicemia. Further reports are really needed to confirm the possible need in these patients for both periprocedural antibiotic and antifungal prophylactic coverage.

A 74-year old woman sought medical attention for general symptoms of nausea, vomiting, and back pain. A computed tomographic scan showed gas in the wall of the descending thoracic and suprarenal aortas. Emergency thoracoabdominal exploration revealed a necrotizing infection of the thoracic aorta extending to the origin of the celiac axis. After surgery Clostridium septicum was identified in tissue culture. Surgical management consisted of in-situ graft replacement of the thoracoabdominal aorta. Three months later, a pseudoaneurysm developed at the distal anastomosis. The patient refused further surgery and died 3 days later. The cause of death was presumed to be a ruptured mycotic aneurysm as a result of recurrent C. septicum infection. The relationship of C. septicum with occult gastrointestinal and hematologic malignancy has been documented. This patient represents the 10th reported case of C. septicum arteritis. Including the nine previous case reports of C. septicum arteritis, the mortality rate is 70%. When evaluating a patient with a mycotic aneurysm or aortitis, C. septicum should be considered. If it is found, a search should be carried out for an associated gastrointestinal or hematologic malignancy. Surgical repair should include extraanatomic revascularization and wide debridement of the infected field. Consideration should be given to lifelong antimicrobial therapy for this potentially fatal infection.

The shorter term beat-to-beat heart rate data collected from the general population are often interrupted by artifacts, and an arbitrary exclusion of such individuals from analysis may significantly reduce the sample size and/or introduce selection bias. A computer algorithm was developed to label as artifacts any data points outside the upper and lower limits generated by a 5-beat moving average +/- 25% (or set manually by an operator using a mouse) and to impute beat-to-beat heart rate throughout an artifact period to preserve the timing relationships of the adjacent, uncorrupted heart rate data. The algorithm applies Fast Fourier Transformation to the smoothed data to estimate low-frequency (LF; 0.025-0.15 Hz) and high-frequency (HF; 0.16-0.35 Hz) spectral powers and the HF/LF ratio as conventional indices of sympathetic, vagal, and vagal-sympathetic balance components, respectively. We applied this algorithm to resting, supine, 2-min beat-to-beat heart rate data collected in the population-based Atherosclerosis Risk in Communities study to assess the performance (success rate) of the algorithm (N = 526) and the inter-and intra-data-operator repeatability of using this computer algorithm (N = 108). Eighty-eight percent (88%) of the records could be smoothed by the computer-generated limits, an additional 4.8% by manually set limits, and 7.4% of the data could not be processed due to a large number of artifacts in the beginning or the end of the records. For the repeatability study, 108 records were selected at random, and two trained data operators applied this algorithm to the same records twice within a 6-month interval of each process (blinded to each other's results and their own prior results). The inter-data-operator reliability coefficients were 0.86, 0.92, and 0.90 for the HF, LF, and HF/LF components, respectively. The average intra-data-operator reliability coefficients were 0.99, 0.99, and 0.98 for the HF, LF, and HF/LF components, respectively. These results indicate that this computer algorithm is efficient and highly repeatable in processing short-term beat-to-beat heart rate data collected from the general population, given that the data operators are trained according to standardized protocol.