Guidelines for the use of carotid endarterectomy: current recommendations from the Canadian Neurosurgical Society

OBJECTIVE: To assess preoperative diagnosis of intra-abdominal acute diseases manifesting as a RAAA and determine treatment options. DESIGN: Retrospective review, with a mean follow-up period of 4 years. SETTING: Vascular Department, Medical School, University "Federico II" of Naples, Italy. METHODS: In 12 patients (8.7%) with clinical suggestion of RAAA were found other intra-abdominal acute lesions, associated with asymptomatic aortic aneurysm in 10 of them and absence in one; the remainder had an intact common iliac artery aneurysm. Sonography was performed in the operating room in 5 patients (41.6%) in shock, 4 hemodynamically stable patients (33.3%) had CT scanning or MRI investigations, while 3 (25%) underwent surgery directly. INTERVENTIONS: Three patients were not operated; one half of patients were submitted to emergency laparotomy and in the remaining 3 patients a preoperative preparation was made. Simultaneous aneurysm repair and nonvascular procedures were performed in 4 patients; nonvascular operations alone were carried out in 5 patients. 4 patients underwent a successful later treatment of their aneurysms: two aneurysmectomy and two endoluminal stenting were done within 4 months. RESULTS: Weight loss and fever were found at 58.3% and 50% of patients with concomitant intra-abdominal acute diseases; both were present in 41.6%. Noninvasive imaging techniques detected associate lesions in 6 of 8 patients (75%) and absence of aneurysm in one having a bleeding adrenal mass. There were three in-hospital deaths: one patient died of metastatic disease without operation and two after surgery (22.2%). Two late deaths from cancer cachexia occurred at 11 months and 3.6 years. CONCLUSIONS: Atypical findings, such as weight loss and fever may be suggestive of coincident lesions in patients with suspected RAAA. Noninvasive assessment may identify associated diseases simulating aneurysmal rupture, without a delay in the treatment. A selective policy of medical or operative therapy may be effective to minimize risk of complications and mortality rate.     

Predictors of early mortality after heart transplantation: the Canadian transplant experience from 1981 to 1992. The CASCADE Investigators. Canadian Study of Cardiac Transplant Atherosclerosis Determinants

OBJECTIVE: To determine risk factors for early death following transplantation in the Canadian heart transplant experience. METHODS: A retrospective multicentre study of the Canadian experience in heart transplantation was performed to evaluate the role of risk factors of early death within 30 days following transplantation. Eight hundred and thirty-three patients older than 15 years underwent cardiac transplantation between 1981 and 1992 in 10 centres across Canada. The association between risk factors and early mortality was analyzed with a multivariate logistic model to examine simultaneously the effect of all risk factors. RESULTS: Seventy-eight patients (9%) died during the first month following transplantation. Recipient age (P = 0.549), sex (P = 0.554) and body mass (P = 0.313) had no effect. Baseline pulmonary vascular resistance (P < 0.001) and systolic pulmonary pressure (P = 0.021) before transplantation were related to early death. Older donors (P = 0.027) were associated with a higher rate of early death but there was no relation with donor sex (P = 0.597), body mass (P = 0.413), blood group (P = 0.227) and ischemic time (P = 0.309). Patients with pulmonary vascular resistance of 6 or greater (Wood units) and donors older than 50 years had relative risks of early death five and two times, respectively, those of patients without these risk factors. CONCLUSION: Patient survival averaged 91% one month following transplantation in the Canadian experience between 1981 and 1992. The two predictors most strongly correlated with early death were elevated pulmonary vascular resistance at baseline and older donors.     

Last ICRU recommendations for the prescription, recording and reporting of external bean therapy]

There is increasing epidemiological evidence in humans which associates low birth weight with later cardiovascular and metabolic disorders including hypertension, insulin resistance, hyperlipidaemia and death from ischaemic heart disease. The molecular mechanisms underlying this link are unknown but fetal glucocorticoid exposure may play a role. In adult mammals, glucocorticoid hormones are involved in control of several physiological processes that maintain homeostasis including coordination of responses to stress. During development, glucocorticoids have important regulatory functions to prepare the organism for metabolic adaptations necessary for extrauterine life. Fetal glucocorticoid load is, in part, regulated by placental and fetal 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) which catalyses a rapid breakdown of maternal and fetal glucocorticoids into inert products. Supraphysiological doses of glucocorticoids retard fetal growth, and human intrauterine growth retardation is associated with elevated cortisol levels. Recent studies have shown that exposing rats to excessive glucocorticoids in utero reduces birth weight and causes permanent hypertension and hyperglycaemia in the adult offspring. These observations show that glucocorticoids could be the link between low birth weight and later disease. Understanding of the molecular details involved in prenatal glucocorticoid action may provide novel insights into the pathogenesis of common cardiovascular and metabolic disorders.     

Effect of gender and left ventricular dysfunction on the incidence of hypotension induced by dobutamine stress echocardiography

BACKGROUND: Of patients who undergo dobutamine stress echocardiography (DSE), 14% to 38% experience hypotension that sometimes requires termination of the test before an adequate cardiac work-load is reached. The mechanisms of hypotension reportedly are related to peripheral vasodilation, a decrease in cardiac output, and left ventricular (LV) cavity obliteration. DSE is performed increasingly in women and in patients with LV dysfunction. However, the impact of gender and LV dysfunction on DSE-induced hypotension has not been elucidated. METHODS AND RESULTS: Clinical, hemodynamic, and echocardiographic characteristics were studied in 412 patients undergoing DSE, 82 patients with an LV ejection fraction of 40% or less, and 147 women. Hypotension, defined as a decrease in systolic blood pressure of at least 20 mm Hg, occurred in 117 (28%) patients. Hypotension was more common in women than men (36% vs 24%, P = .01). Hypotension was also more common in older adults (P = .004), persons taking diuretics (P = .025) or angiotensin-converting enzyme inhibitors (P = .01), and persons with higher baseline blood pressures (P < .0001). Hypotension was not related to the use of beta blockers, calcium channel blockers, digoxin, nitrates, LV dimensions, or ejection fraction. CONCLUSIONS: The incidence of DSE-induced hypotension is related to gender but not to the level of LV systolic function. It also is associated significantly with higher age, and use of angiotensin-converting enzyme inhibitors or diuretics.     

Early effects of coronary artery bypass surgery and cold cardioplegic ischemia on left ventricular diastolic function: evaluation by computer-assisted transesophageal echocardiography

OBJECTIVE: Although left ventricular (LV) systolic function undergoes a temporary decrease after cardiopulmonary bypass (CPB) in patients undergoing coronary artery bypass grafting (CABG), data on the effects of CABG and cardioplegic arrest on LV diastolic function are contradictory. The objective of the present study was to further evaluate the effects of CABG and CPB on LV diastolic function. DESIGN: A prospective study. SETTING: A multi-institutional investigation at a university hospital. PARTICIPANTS: 20 patients on beta-receptor antagonists, scheduled for CABG and with a preoperative ejection fraction over 0.5. INTERVENTIONS: Central hemodynamic measurements, transesophageal LV short-axis images, and mitral Doppler flow profiles were obtained before and after volume loading that in turn was performed both before surgical incision and after weaning from CPB. MEASUREMENTS AND MAIN RESULTS: Heart rate, cardiac output, and peak atrial filling velocity increased; systemic vascular resistance decreased; whereas stroke volume, LV area ejection fraction, deceleration rate and slope of early diastolic filling, time-velocity integral of early diastolic filling, and the ratio between early and atrial peak filling velocity were unchanged post-CPB compared with pre-CPB. LV end-diastolic stiffness that was calculated for each patient pre-CPB and post-CPB using the formula: P = B*eS*A), where P is the LV filling pressure and A is the end-diastolic short-axis area, was unchanged post-CPB compared with pre-CPB. CONCLUSIONS: Both the active and passive components of LV diastolic function are well maintained shortly after CABG and cardioplegic arrest in patients with a good preoperative systolic LV function.     

Adherence to management of high blood pressure: recommendations of the Canadian Coalition for High Blood Pressure Prevention and Control

Adherence or compliance, in the context of medical treatment, refers to how well a patient follows and sticks to the management plan developed with her/his health care provider, which may include pharmacologic agents as well as changes in lifestyle. Adherence is of great concern in asymptomatic conditions such as hypertension, where lack of control may have serious ramifications including end organ damage and premature mortality. To address this issue, the Canadian Coalition for High Blood Pressure Prevention and Control established a national Advisory Committee on Adherence to the Management of High Blood Pressure. The Advisory Committee consisted of 11 members from different disciplines of health care providers. The Committee reviewed all evidences to date and drew up four practical recommendations with respect to patient, provider and environment. Based on Canadian Task Force on Periodic Health Examination's guidelines, all four recommendations can be classified as 'level C' with a quality of evidence of II.     

A new approach for evaluation of left ventricular diastolic function: spatial and temporal analysis of left ventricular filling flow propagation by color M-mode Doppler echocardiography

OBJECTIVES: To evaluate left ventricular diastolic function and differentiate the pseudonormalized transmitral flow pattern from the normal pattern, the propagation of left ventricular early filling flow was assessed quantitatively using color M-mode Doppler echocardiography. BACKGROUND: Because the propagation of left ventricular early filling flow is disturbed in the left ventricle with impaired relaxation, quantification of such alterations should provide useful indexes for the evaluation of left ventricular diastolic function. METHODS: Study subjects were classified into three groups according to the ratio of early to late transmitral flow velocity (E/A ratio) and left ventricular ejection fraction: 29 subjects with an ejection fraction > or = 60% (control group); 34 with an ejection fraction < 60% and E/A ratio < 1 (group I); and 25 with ejection fraction < 60% and E/A ratio > or = 1 (group II). The propagation of peak early filling flow was visualized by changing the first aliasing limit of the color Doppler signals. The rate of propagation of peak early filling flow velocity was defined as the distance/time ratio between two sampling points: the point of the maximal velocity around the mitral orifice and the point in the mid-left ventricle at which the velocity decreased to 70% of its initial value. High fidelity manometer-tipped measurement was performed in 40 randomly selected subjects. RESULTS: The rate of propagation decreased in groups I and II compared with that in the control group (33.8 +/- 13.8 [mean +/- SD] and 30.0 +/- 8.6 vs. 74.3 +/- 17.4 cm/s, p < 0.001, respectively) and correlated inversely with the time constant of left ventricular isovolumetric relaxation and the minimal first derivative of left ventricular pressure (peak negative dP/dt) (r = 0.82 and r = 0.72, respectively). CONCLUSIONS: Spatial and temporal analysis of filling flow propagation by color M-mode Doppler echocardiography was free of pseudonormalization and correlated well with the invasive variables of left ventricular relaxation.     

Transesophageal echocardiography in mitral prosthesis dysfunction: usefulness and limitations in the evaluation of mitral insufficiency

This study was performed to test the usefulness of transesophageal echocardiography in the diagnosis and assessment of pathological mitral regurgitation in patients with mitral valve prostheses. Doppler color flow imaging by transesophageal echocardiography was compared to the transthoracic echocardiography and angiographic and surgical assessment. We analyzed the influence of the spatial configuration of the jet on the semiquantitative assessment of mitral regurgitation. We studied 71 patients with prostheses in mitral position which were submitted for transesophageal echocardiography examination. 51 of these patients were found to have a pathological prosthetic regurgitation that was confirmed in 21 cases by left ventriculography and in 4 during cardiac surgery. Transesophageal echocardiography Doppler color flow imaging identified a regurgitant jet in 31 patients (60.7%). There was complete agreement with the quantitative assessment of regurgitation by angiography or surgery in 36% of the cases. All patients with prosthetic insufficiency observed by angiography or during cardiac surgery were confirmed by transesophageal echocardiography. Complete agreement in grade of severity by transthoracic echocardiography was found in 84% of cases. There was a difference in grade of severity of mitral regurgitation in only 4 patients. Regurgitant jets were classified by transesophageal echocardiography color Doppler in two groups: free jets and impinging wall jets. 21 cases presented a free jet and 31 excentrically directed impinging wall jet of mitral regurgitation. There was complete agreement with hemodynamic assessment of severity in all patients with regurgitant free jets (11/11). In presence of jet wall there was understimation of mitral regurgitation in 28.5% (4/13).(ABSTRACT TRUNCATED AT 250 WORDS)     

Dimensions of the proximal thoracic aorta from childhood to adult age: reference values for two-dimensional echocardiography. Ligurian Group of SIEC (Italian Society of Echocardiography)

BACKGROUND: Two-dimensional echocardiography (2-DE) represents the main tool for detecting and monitoring abnormalities of proximal thoracic aorta. However, previous studies performed to assess the reference values of aortic diameters using this technique are few and, often, involve a small number of subjects. Furthermore, such a study has not been performed on an Italian population. METHODS: To assess the reference values and the growth curves of the dimensions of the proximal thoracic aorta in an Italian population, we measured aortic diameters at the level of the anulus, of the sinuses of Valsalva and of the supraaortic ridge, by using 2-DE, in 134 healthy volunteers (78 males, 56 females), aged 35 +/- 16 years (range 5-76). Sex, age, weight, height, body surface area (BSA), heart rate, systolic and diastolic blood pressure were analyzed as determinants of proximal thoracic aorta diameters. In addition, to compare the specificity of the reference values, we have obtained with those provided by literature, we studied another independent group of 23 healthy volunteers, aged 32 +/- 15 years (range 11-65). RESULTS: In our study population, mean values and range of aortic 2-DE diameters were 2.1 +/- 0.3 cm (range 1.3-2.9) at the level of the anulus, 2.6 +/- 0.4 cm (range 1.7-3.7) at the level of the sinuses of Valsalva and 2.4 +/- 0.4 cm (range 1.5-3.4) at the level of the supraaortic ridge. At multivariate regression analysis, sex and age emerged as the only independent determinants of the aortic root diameters (r2 = 0.35, 0.43, and 0.52 for aortic diameter at the level of anulus, sinuses of Valsalva, and supraaortic ridge, respectively). On average, aortic root dimensions at the level of the anulus, of the sinuses of Valsalva and of the supraaortic ridge in females were 1.5 mm, 2.8 mm, and 1 mm, respectively, smaller than those of males of comparable age, height and weight. The growth curves showed that proximal thoracic aorta increases in size in the first 30 years of life; thereafter, it remains relatively constant in size up to 55 years, after which the proximal thoracic aorta tends to enlarge gradually. The ratios of sinuses of Valsalva to annular diameter and of supraaortic ridge to annular diameter (1.27 +/- 0.17 and 1.17 +/- 0.16, respectively) were found to be indexes of aortic root dimension independent of sex and age. No correlation was found between aortic root dimensions and systolic blood pressure. M-mode echocardiography systematically overestimated 2-DE aortic diameters at the level of the anulus, as well as at the level of the sinuses of Valsalva and of the supraaortic ridge (+0.8 +/- 0.04 cm, +0.2 +/- 0.04 cm, and +0.4 +/- 0.04 cm, respectively, p < 0.0001 for all). In the control population, our reference values demonstrated a specificity significantly higher than that of the main reference values reported in literature (97 +/- 2% versus 62 +/- 4%, p < 0.0001). CONCLUSIONS: Our study provides a prospectic, systematic and detailed analysis of 2-DE proximal thoracic aorta diameters in a wide group of healthy Italian subjects. Our data show that: 1) 2-DE aortic root dimensions are influenced by sex and age but not by body size or blood pressure; 2) the ratios of sinuses of Valsalva to annular diameter and of supraaortic ridge to annular diameter are indexes of aortic root dimension which are independent of age and sex; 3) M-mode diameter systematically overestimates 2-DE diameters of the aortic root; and 4) Italian population based reference values showed higher specificity than values provided by literature.     

Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy

OBJECTIVE: To provide Canadian physicians with comprehensive, evidence-based guidelines for the nonpharmacologic management and prevention of gestational hypertension and pre-existing hypertension during pregnancy. OPTIONS: Lifestyle modifications, dietary or nutrient interventions, plasma volume expansion and use of prostaglandin precursors or inhibitors. OUTCOMES: In gestational hypertension, prevention of complications and death related to either its occurrence (primary or secondary prevention) or its severity (tertiary prevention). In pre-existing hypertension, prevention of superimposed gestational hypertension and intrauterine growth retardation. EVIDENCE: Articles retrieved from the pregnancy and childbirth module of the Cochrane Database of Systematic Reviews; pertinent articles published from 1966 to 1996, retrieved through a MEDLINE search; and review of original randomized trials from 1942 to 1996. If evidence was unavailable, consensus was reached by the members of the consensus panel set up by the Canadian Hypertension Society. VALUES: High priority was given to prevention of adverse maternal and neonatal outcomes in pregnancies with established hypertension and in those at high risk of gestational hypertension through the provision of effective nonpharmacologic management. BENEFITS, HARMS AND COSTS: Reduction in rate of long-term hospital admissions among women with gestational hypertension, with establishment of safe home-care blood pressure monitoring and appropriate rest. Targeting prophylactic interventions in selected high-risk groups may avoid ineffective use in the general population. Cost was not considered. RECOMMENDATION: Nonpharmacologic management should be considered for pregnant women with a systolic blood pressure of 140-150 mm Hg or a diastolic pressure of 90-99 mm Hg, or both, measured in a clinical setting. A short-term hospital stay may be required for diagnosis and for ruling out severe gestational hypertension (preeclampsia). In the latter case, the only effective treatment is delivery. Palliative management, dependent on blood pressure, gestational age and presence of associated maternal and fetal risk factors, includes close supervision, limitation of activities and some bed rest. A normal diet without salt restriction is advised. Promising preventive interventions that may reduce the incidence of gestational hypertension, especially with proteinuria, include calcium supplementation (2 g/d), fish oil supplementation and low-dose acetylsalicylic acid therapy, particularly in women at high risk for early-onset gestational hypertension. Pre-existing hypertension should be managed the same way as before pregnancy. However, additional concerns are the effects on fetal well-being and the worsening of hypertension during the second half of pregnancy. There is, as yet, no treatment that will prevent exacerbation of the condition. VALIDATION: The guidelines share the principles in consensus reports from the US and Australia on the nonpharmacologic management of hypertension in pregnancy.     

Effect of myocardial hypertrophy on systolic and diastolic function in children: insights from the force-frequency and relaxation-frequency relationships

OBJECTIVE: The objective of this study was to evaluate the effect of myocardial hypertrophy on systolic and diastolic properties of the left ventricle in children. BACKGROUND: In children with myocardial hypertrophy, ejection phase indices are invariably increased. However, indices of force-generation, e.g., end-systolic elastance and invasive indices of diastolic properties, have been studied infrequently in children with myocardial hypertrophy. METHODS: We studied 10 children with congenital aortic stenosis or coarctation of aorta and nine control patients. Systolic properties were assessed from shortening fraction, end-systolic fiber elastance (Ef(es)) measured at resting heart rates, and force-frequency relationship measured at heart rates increasing from 110 to 160 beats per minute. Diastolic properties were assessed from time constant of relaxation (tau) at matched heart rates, chamber stiffness constant, myocardial stiffness constant, and relaxation-frequency relationship measured at gradually increasing heart rates. RESULTS: Ef(es) remained unchanged by myocardial hypertrophy, however, tau was prolonged (tauL: 27.3+/-2.3 vs. 21.8+/-2.2 ms, p < 0.001; and tauD: 43.2+/-3.1 vs. 34.3+/-3.3 ms, p < 0.001). Both chamber and myocardial stiffness constants remained unchanged. Incremental increases in heart rate produced incremental improvement in both contraction and relaxation. Slopes of force-frequency and relaxation-frequency relationships remained unchanged in the experimental group. However, the relaxation-frequency relationship manifested a parallel shift upward. CONCLUSIONS: In conscious, sedated children with myocardial hypertrophy, systolic function assessed by an index of force generation remains unchanged. However, relaxation is prolonged but passive diastolic properties remain unaffected. The combined effect of hypertrophy and heart rate does not alter the force-frequency and relaxation-frequency relationships.     

Carcinoma of the male breast: a review and recommendations for management

OBJECTIVES: To investigate whether occupational exposure to organic solvents increases the risk of dementia. METHODS: Cases of dementia were identified from the computed tomography records of eight neuroradiology centres in England and Wales, and were compared with two sets of controls investigated at the same centres. The first set of controls were patients with brain cancer and the second set were patients with other disorders that were not chronically disabling. Lifetime occupational histories were obtained through a postal questionnaire completed by the subjects or their next of kin. Associations between dementia and occupation were examined by logistic regression. RESULTS: Usable questionnaires were returned for 204 (61%) of the cases, 225 (51%) of the controls with brain cancer, and 441 (61%) of the other controls. The findings with each of the two sets of controls were similar. In comparison with all controls combined, cases had less often worked ever as a painter or printer (odds ratio (OR) 0.6, 95% confidence interval (95% CI) 0.3 to 1.2), and were less likely to have worked for > 1 year as a printer, painter, or launderer or dry cleaner (OR 0.6, 95% CI 0.3 to 1.4). CONCLUSIONS: These findings provide no support for the hypothesis that occupational exposure to solvents is a cause of dementia. An excess risk in subsets of workers with extremes of exposure cannot be discounted, but the data indicate that any influence of exposure to solvents on the overall incidence of severe dementia in the general population of England and Wales is small.     

Accuracy and feasibility of contrast echocardiography for detection of perfusion defects in routine practice: comparison with wall motion and technetium-99m sestamibi single-photon emission computed tomography. The Nycomed NC100100 Investigators

OBJECTIVES: We sought to assess the feasibility and accuracy of myocardial contrast echocardiography (MCE) using standard imaging approaches for the detection of perfusion defects in patients who had a myocardial infarction (MI). BACKGROUND: Myocardial contrast echocardiography may be more versatile than perfusion scintigraphy for identifying the presence and extent of perfusion defects after MI. However, its reliability in routine practice is unclear. METHODS: Fundamental or harmonic MCE was performed with continuous or triggered imaging in 203 patients with a previous MI using bolus doses of a perfluorocarbon-filled contrast agent (NC100100). All patients underwent single-photon emission computed tomography (SPECT) after the injection of technetium-99m (Tc-99m) sestamibi at rest. Quantitative and semiquantitative SPECT, wall motion and digitized echocardiographic data were interpreted independently. The accuracy of MCE was assessed for detection of segments and patients with moderate and severe sestamibi-SPECT defects, as well as for detection of patients with extensive perfusion defects (>12% of left ventricle). RESULTS: In segments with diagnostic MCE, the segmental sensitivity ranged from 14% to 65%, and the specificity varied from 78% to 95%, depending on the dose of contrast agent. Using both segment- and patient-based analysis, the greatest accuracy and proportion of interpretable images were obtained using harmonic imaging in the triggered mode. For the detection of extensive defects, the sensitivity varied from 13% to 48%, with specificity from 63% to 100%. Harmonic imaging remained the most accurate approach. Time since MI and SPECT defect location and intensity were all determinants of the MCE response. The extent of defects on MCE was less than the extent of either abnormal wall motion or SPECT abnormalities. The combination of wall motion and MCE assessment gave the best balance of sensitivity (46% to 55%) and specificity (82% to 83%). CONCLUSIONS: Although MCE is specific, it has limited sensitivity for detection of moderate or severe perfusion defects, and it underestimates the extent of SPECT defects. The best results are obtained by integration with wall motion. More sophisticated methods of acquisition and interpretation are needed to enhance the feasibility of this technique in routine practice.