Strobilurin fungicide increases the susceptibility of amphibian larvae to trematode infections

The global rise in fungal pathogens has driven the increased usage of fungicides, yet our understanding of their ecotoxicity remains largely limited to acute toxicity. While such data is critical for projecting the risk of fungicide exposure to individual species, the contamination of natural systems with fungicides also has the potential to alter species interactions within communities including host-parasite relationships. We examined the effects of the fungicide pyraclostrobin on the susceptibility of larval American bullfrogs (Rana catesbeiana) to trematode (echinostome) infections using a controlled laboratory experiment. Following a 2-wk exposure to 0, 1.0, 5.2, or 8.4 µg/L of pyraclostrobin, tadpoles were then exposed to parasites either in the 1) presence (continued/simultaneous exposure) or 2) absence (fungicide-free water) of pyraclostrobin. We found that when exposed to pyraclostrobin during parasite exposure, meta cercariae counts increased 4 to 8 times compared to control tadpoles. Additionally, parasite loads were approximately 2 times higher in tadpoles with continued fungicide exposures compared to tadpoles that were moved to fresh water following fungicide exposure. This research demonstrates that fungicides at environmentally relevant concentrations can indirectly alter host-parasite interactions, which could elevate disease risk. It also underscores the need for studies that expand beyond traditional toxicity experiments to assess the potential community and ecosystem-level implications of environmental contaminants.

Acute aquatic toxicity of two commonly used fungicides to midwestern amphibian larvae

Fungicide usage has increased globally in response to the rise in fungal pathogens, especially in the agricultural sector. However, research examining the toxicity of fungicides is still limited for many aquatic species. In this study, we examined the acute toxicity of two widely used fungicides, chlorothalonil and pyraclostrobin, on six North American larval amphibian species across multiple families using 96-h LC50 tests. We found that pyraclostrobin was approximately 3.5x more toxic than chlorothalonil; estimated LC50 values ranged from 5-18 µg/L for pyraclostrobin and 15-50 µg/L for chlorothalonil. Comparing across amphibian groups, we found that salamanders were 3x more sensitive to pyraclostrobin than anuran species and equally as sensitive to chlorothalonil. Notably, our estimated LC50 values within the range of the expected environmental concentration for these fungicides suggesting environmental exposures could lead to direct mortality in these species. Given the widespread and increasing usage of fungicides, additional work should be conducted to assess the general risk posed by these chemicals to amphibian and their associated aquatic habitats.

Effects of Referral to a Specialist for Headache

Patients consulting neurological outpatient clinics for headaches that were found not to be due to a serious structural lesion were followed up one year afterwards. Considerable improvement in symptoms was found in the sample. This was only partly attributable to any medical treatment received at the clinics or subsecquently from a general practitioner. Improvement was associated with previously expressed satisfaction with the clinic consultation, and a nonspecific ‘placebo’ response is postulated.

Varying definitions for periprocedural myocardial infarction alter event rates and prognostic implications

BACKGROUND

Periprocedural myocardial infarction (PMI) has had several definitions in the last decade, including the Society for Cardiovascular Angiography and Interventions (SCAI) definition, that requires marked biomarker elevations congruent with surgical PMI criteria.

METHODS AND RESULTS

The aim of this study was to examine the definition-based frequencies of PMI and whether they influenced the reported association between PMI and increased rates of late death/ myocardial infarction (MI). We studied 742 patients; 492 (66%) had normal troponin T (TnT) levels and 250 (34%) had elevated, but stable or falling, TnT levels. PMI, using the 2007 and the 2012 universal definition, occurred in 172 (23.2%) and in 99 (13.3%) patients, respectively, whereas 19 (2.6%) met the SCAI PMI definition (P<0.0001). Among patients with PMI using the 2012 definition, occlusion of a side branch ≤1 mm occurred in 48 patients (48.5%) and was the most common angiographic finding for PMI. The rates of death/MI at 2 years in patients with, compared to those without, PMI was 14.7% versus 10.1% (P=0.087) based on the 2007 definition, 16.9% versus 10.3% (P=0.059) based on the 2012 definition, and 29.4% versus 10.7% (P=0.015) based on the SCAI definition.

CONCLUSION

In this study, PMI, according to the SCAI definition, was associated with more-frequent late death/MI, with ≈20% of all patients, who had PMI using the 2007 universal MI definition, not having SCAI-defined PMI. Categorizing these latter patients as SCAI-defined no PMI did not alter the rate of death/MI among no-PMI patients.

Bare-metal stenting of large coronary arteries in ST-elevation myocardial infarction is associated with low rates of target vessel revascularization

BACKGROUND

During percutaneous coronary intervention (PCI) performed in the emergent setting of ST-segment elevation myocardial infarction (STEMI), uncertainty about patients' ability to comply with 12 months dual antiplatelet therapy after drug-eluting stenting is common, and thus, selective bare-metal stent (BMS) deployment could be an attractive strategy if this achieved low target vessel revascularization (TVR) rates in large infarct-related arteries (IRAs) (≥3.5 mm).

METHODS AND RESULTS

To evaluate this hypothesis, among 1,282 patients with STEMI who underwent PCI during their initial hospitalization, we studied 1,059 patients (83%) who received BMS, of whom 512 (48%) had large IRAs ≥3.5 mm in diameter, 333 (31%) had IRAs 3 to 3.49 mm, and 214 (20%) had IRAs <3 mm. At 1 year, TVR rate in patients with BMS was 5.8% (2.2% with large BMS [≥3.5 mm], 9.2% with BMS 3-3.49 mm [intermediate], and 9.0% with BMS <3.0 mm [small], P < .001). The rates of death/reinfarction among patients with large BMS compared with intermediate BMS or small BMS were lower (6.6% vs 11.7% vs 9.0%, P = .042). Among patients who received BMS, the independent predictors of TVR at 1 year were the following: vessel diameter <3.5 mm (odds ratio [OR] 4.39 [95% CI 2.24-8.60], P < .001), proximal left anterior descending coronary artery lesions (OR 1.89 [95% CI 1.08-3.31], P = .027), hypertension (OR 2.01 [95% CI 1.17-3.438], P = .011), and prior PCI (OR 3.46 [95% CI 1.21-9.85], P = .02). The predictors of death/myocardial infarction at 1 year were pre-PCI cardiogenic shock (OR 8.16 [95% CI 4.16-16.01], P < .001), age ≥65 years (OR 2.63 [95% CI 1.58-4.39], P < .001), left anterior descending coronary artery culprit lesions (OR 1.95 [95% CI 1.19-3.21], P = .008), female gender (OR 1.93 [95% CI 1.12-3.32], P = .019), and American College of Cardiology/American Heart Association lesion classes B2 and C (OR 2.17 [95% CI 1.10-4.27], P = .026).

CONCLUSION

Bare-metal stent deployment in STEMI patients with IRAs ≥3.5 mm was associated with low rates of TVR. Their use in this setting warrants comparison with second-generation drug-eluting stenting deployment in future randomized clinical trials.

Safety and efficacy of rescue angioplasty for ST-elevation myocardial infarction with high utilization rates of glycoprotein IIb/IIIa inhibitors

BACKGROUND

Fibrinolytic therapies remain widely used for ST-elevation myocardial infarction, and for "failed reperfusion," rescue percutaneous coronary intervention (PCI) is guideline recommended to improve outcomes. However, these recommendations are based on data from an earlier era of pharmacotherapy and procedural techniques.

METHODS AND RESULTS

To determine factors affecting prognosis after rescue PCI, we studied 241 consecutive patients (median age 55 years, interquartile range [IQR] 48-65) undergoing procedures between 2001 and 2009 (53% anterior ST-elevation myocardial infarction and 78% transferred). The median treatment-related times were 1.2 hours (IQR 0.8-2.2) from symptom onset to door, 2 hours (IQR 1.3-3.2) from symptom onset to fibrinolysis (93% tenecteplase), and 3.9 hours (IQR 3.1-5.2) from fibrinolysis to balloon. Procedural characteristics were stent deployment in 95% (11.6% drug eluting) and 78% glycoprotein IIb/IIIa inhibitor use, and Thrombolysis In Myocardial Infarction (TIMI) 3 flow rates pre-PCI and post-PCI were 41% and 91%, respectively (P < .001). At 30 days, TIMI major bleeding occurred in 16 (6.6%) patients, and 23 (9.5%) patients received transfusions; nonfatal stroke occurred in 4 (1.7%) patients (2 hemorrhagic). Predictors of TIMI major bleeding were female gender (odds ratio 3.194, 95% CI 1.063-9.597; P = .039) and pre-PCI shock (odds ratio 3.619, 95% CI,1.073-12.207; P = .038). Mortality at 30 days was 6.2%, and 3.2% in patients without pre-PCI shock. One-year mortality was 8.2% (5.3% in patients without pre-PCI cardiogenic shock), 5.2% had reinfarction, and the target vessel revascularization rate was 6.4% (2.6% in arteries ≥ 3.5 mm in diameter). Pre-PCI shock, female gender, and post-PCI TIMI flow grades ≤ 2 were significant predictors of 1-year mortality on multivariable regression modeling, but TIMI major bleeding was not.

CONCLUSIONS

Rescue PCI with contemporary treatments can achieve mortality rates similar to rates for contemporary primary PCI in patients without pre-PCI shock. Whether rates of bleeding can be reduced by different pharmacotherapies and interventional techniques needs clarification in future studies.

Evaluation of troponin T criteria for periprocedural myocardial infarction in patients with acute coronary syndromes

In patients with acute coronary syndromes undergoing percutaneous coronary intervention (PCI), the diagnosis of periprocedural myocardial infarction is often problematic when the pre-PCI levels of cardiac troponin T (TnT) are elevated. Thus, we examined different TnT criteria for periprocedural myocardial infarction when the pre-PCI TnT levels were elevated and also the associations between the post-PCI cardiac marker levels and outcomes. We established the relation between the post-PCI creatine kinase-MB (CKMB) and TnT levels in 582 patients (315 with acute coronary syndromes and 272 with stable coronary heart disease). A post-PCI increase in the CKMB levels to 14.7 μg/L (3 × the upper reference limit [URL] in men) corresponded to a TnT of 0.23 μg/L. In the 85 patients with acute coronary syndromes and normal CKMB, but elevated post peak TnT levels before PCI (performed at a median of 5 days, interquartile range 3 to 7), the post-PCI cardiac marker increases were as follows: 21 (24.7%) with a ≥ 20% increase in TnT, 10 (11.8%) with an CKMB level >3 × URL, and 12 (14%) with an absolute TnT increase of >0.09 μg/L (p <0.005 for both). In the patients with stable coronary heart disease and post-PCI cardiac markers > 3× URL compared to those without markers elevations, the rate of freedom from death or nonfatal myocardial infarction was 88% for those with TnT elevations versus 99% (p <0.001, log-rank) and 84% for those with CKMB elevations versus 98% (p <0.001, log-rank). Of the patients with acute coronary syndromes, the post-PCI marker levels did not influence the outcomes. In conclusion, in patients with acute coronary syndromes and elevated TnT levels undergoing PCI several days later, ≥20% increases in TnT were more common than absolute increments in the TnT or CKMB levels of >3× URL. Also, periprocedural cardiac marker elevations in patients with acute coronary syndromes did not have prognostic significance.

How compliant are we with guidelines for coronary angiography in clinical practice?

BACKGROUND

The American College of Cardiology and American Heart Association have published guidelines for coronary angiography. We evaluated the compliance rate with these guidelines in clinical practice, its correlation to results of angiography and aimed to identify problem areas of non-compliance.

METHODS

We prospectively evaluated 802 consecutive referrals for coronary angiography over 5 months in 2002 in a tertiary referral hospital. These referrals were assessed by two independent reviewers blinded to the results of angiography.

RESULTS

Patient age was 62 +/- 11 years (522 men, 433 inpatients, 369 day-only patients). Referrals were outside published guidelines in 34.3 and 36.2% as evaluated by the two reviewers (concordance rate 88.2%, kappa = 0.74, p < 0.001). Intraobserver agreement was 97.5%. The rate of angiography showing either normal arteries or only minor diseases (<50%) was higher for referrals outside guidelines (68.4 vs 22.6%, P < 0.001). Compliance rate was high with indications of non-ST-elevation myocardial infarction (99.2%) and ST-elevation myocardial infarction (95.8%), valvular disease (80%) and arrhythmia (80%). Compliance rate was lower with assessment of dyspnoea or heart failure (74.3%) and before non-cardiac surgery (72.7%) and was particularly low with assessment of chest pain (53.2%). Younger age (odds ratio (OR) 1.04, P < 0.001), female sex (OR 2.67, P < 0.001), day-only procedure (OR 2.27, P < 0.001) and non-invasive cardiologist referrer (OR 1.41, P = 0.046) were independent predictors of non-compliance.

CONCLUSION

Referrals for coronary angiography were outside guidelines in a significant proportion of patients. Rate of negative angiography was higher when the referrals were outside guidelines. Problematic areas of non-compliance could be identified. Measures specifically targeting these areas may be more effective in improving the overall guideline compliance in clinical practice.

Use of functional tests before angiography in patients with normal coronary arteries

BACKGROUND

Functional tests provide diagnostic and prognostic information in patients with suspected coronary disease and are recommended in investigating and guiding management of these patients. There is little data on their utilization, especially in patients with low to intermediate pre-test probability of disease.

METHODS

From 6053 consecutive patients who underwent 6830 coronary angiograms for suspected coronary disease, 758 patients were subsequently found to have normal coronary arteries. Clinical data, functional tests performed prior to angiography and referring physicians were analyzed.

RESULTS

The 758 patients had mean pre-test probability of disease of 42+/-30%. Only 483 patients had undergone functional tests before angiography. There were no differences in gender, age, and pre-test probability between patients who underwent functional tests and those who did not. Three hundred thirteen patients underwent angiography as inpatients while 445 were day-only patients. Inpatients were less likely to have undergone functional tests prior to angiography. Inpatient status was the only independent predictor of not undergoing functional tests (OR 5.9, p<0.001). Functional tests revealed inducible ischaemia in only 241 of the 483 patients. Patients referred by cardiologists were more likely to have undergone functional tests compared with those referred by other physicians. Procedural cardiologists and non-procedural cardiologists had similar rate of use of functional tests.

CONCLUSIONS

In our patients with normal coronary arteries, utilization of functional tests was low, particularly for inpatients. A significant proportion proceeded to angiography despite negative functional tests. Referrer characteristics and inpatient status, rather than pre-test probability, appeared to have greater impact on utilization of functional tests.

Adverse Reactions of Low Osmolar Non-Ionic and Ionic Contrast Media When Used Together or Separately During Percutaneous Coronary Intervention

BACKGROUND

Due to perceived advantages in the use of non-ionic contrast agents for diagnostic angiography and ionic agents for percutaneous coronary intervention (PCI), patients often receive various combinations of both types of agents.

AIM

To assess potential adverse effects of non-ionic and ionic contrast media when used together or separately during percutaneous coronary intervention.

METHODS

We retrospectively evaluated the outcomes of 532 patients undergoing percutaneous coronary intervention in our institution. Patients were divided into two groups: those that underwent diagnostic angiography and "follow on" PCI; and those that underwent "planned" PCI. The groups were subdivided on the basis of the use of the ionic agent ioxaglate or the non-ionic agent iopromide during PCI. The frequency of allergic reactions and major adverse cardiac events (MACE) were noted.

RESULTS

With respect to the "follow on" group, allergic reactions occurred in 9 of 150 patients (6.0%) who received the combination of ioxaglate and iopromide versus 1 of 93 (1.1%) who only received iopromide (p=0.094). There was no difference with respect to MACE [6 (4.0%) ioxaglate and iopromide versus 4 (4.3%) iopromide alone, p=1.00]. In the "planned" group, 7 of 165 patients (4.2%) receiving ioxaglate had an allergic reaction as opposed 0.0% (0 of 124 patients) in the iopromide group (p=0.021). All contrast reactions were mild. The incidence of a MACE was similar in both groups [1 (0.6%) ioxaglate versus 2 (1.6%) iopromide, p=0.579]. The incidence of allergic reactions was similar if ioxaglate was used alone or in combination with iopromide (p=0.478).

CONCLUSIONS

Whilst combining ionic and non-ionic contrast agents in the same procedure was not associated with any more adverse reactions than using an ionic contrast agent alone, the ionic contrast agent ioxaglate was associated with the majority of allergic reactions. With respect to choice of contrast agent, using the non-ionic agent iopromide alone for coronary intervention is associated with the lowest risk of an adverse event.

Comparison of 6 and 7 French guiding catheters for percutaneous coronary intervention: Results of a randomised trial with a vascular ultrasound endpoint

OBJECTIVE

To perform a randomized, ultrasound controlled trial to define the procedural and clinical advantages and limitations of 6 French (Fr) compared with 7 Fr transfemoral coronary intervention in the stenting era.

BACKGROUND

The use of 7 Fr guiding catheters may facilitate Percutaneous Coronary Intervention (PCI), but may be associated with increased vascular complications when compared with 6 Fr catheters.

METHODS

Patients undergoing PCI considered suitable for either a 6 or 7 Fr sheath and guiding catheter system were included. All vascular sheaths were removed with assisted manual compression. Femoral vascular ultrasounds were performed prior to hospital discharge and interpreted by a vascular surgeon blinded to treatment assignment. The primary endpoint was a composite of significant vascular complications including major haematoma, retroperitoneal haematoma, pseudoaneurysm, arterio-venous fistula, or femoral venous or arterial thrombosis.

RESULTS

During the study, 414 patients (mean age 61+/-11 years, 27% females) were randomly assigned to 6 Fr or 7 Fr sheath groups. The incidence of major vascular complications was 5.7% in the 6 Fr group and 3.9% in the 7 Fr group (P=0.383). There was no significant difference in procedural or angiographic success between the groups. The use of contrast volume was higher in the 7 Fr group (157+/-58 ml vs. 144+/-58 ml; P=0.029). There was a trend toward better operator satisfaction with the 7 Fr guide (P=0.08).

CONCLUSIONS

This prospective, randomized trial indicates no reduction in major peripheral vascular complications with the use of smaller guiding catheters in PCI. There was less contrast used in the 6 Fr group, which may benefit some patient subsets, however operators tended to prefer the larger 7 Fr system. The target coronary anatomy and need for complex device intervention should mandate the choice of guiding catheter size, not a perceived impact on vascular complications.

A randomized comparison of clopidogrel and aspirin versus ticlopidine and aspirin after coronary stent implantation

BACKGROUND

The combination of a thienopyridine and aspirin has become the standard of care after intracoronary stenting. Clopidogrel appears to be better tolerated than ticlopidine but may be associated with more adverse cardiac events. We assessed the tolerability and efficacy of 2 weeks of therapy with ticlopidine and aspirin in comparison to clopidogrel and aspirin after coronary stent implantation.

METHODS

Patients with successful intracoronary stent implantation at our institution were randomly assigned, in addition to aspirin, to receive either ticlopidine or clopidogrel. Loading doses were administered immediately after the procedure, and the drugs were continued for 2 weeks.

RESULTS

Three hundred seven patients were randomly assigned: 154 patients to clopidogrel and 153 to the ticlopidine group. The primary end point of early drug discontinuation occurred in 5 patients (3.3%) in the ticlopidine group and 1 patient (0.6%) in the clopidogrel group (P =.121). Within 30 days, thrombotic stent occlusion occurred in 1 patient (0.7%) in the ticlopidine group and 3 patients (1.9%) in the clopidogrel group (P =.623). A major adverse cardiac event occurred in 3 patients (approximately 1.9%; P = 1.00) in each group.

CONCLUSIONS

There was a nonsignificant trend to improved tolerability of a 2-week regimen of clopidogrel and aspirin when compared with ticlopidine and aspirin in patients undergoing intracoronary stent implantation. The combination of clopidogrel and aspirin results in a comparably low incidence of major adverse cardiac events when compared with ticlopidine and aspirin.

Patient tolerance and resource utilization associated with an arterial closure versus an external compression device after percutaneous coronary intervention

We assessed patient tolerance and resource utilization of using the AngioSeal closure device versus assisted manual compression using the Femostop device after percutaneous coronary intervention (PCI). Patients undergoing PCI with clean arterial access and no procedural hematoma were randomized to receive the AngioSeal or Femostop device to achieve femoral arterial hemostasis. Times from procedure end to removal from angiography table, hemostasis, ambulation, and hospital discharge were recorded. Bedside nursing/medical officer care time, vascular complications, and disposable use were also documented. Patient comfort was assessed using Present Pain Intensity and Visual Analogue scales at baseline, 4 hr, 8 hr, and the morning after the procedure. One hundred twenty-two patients were enrolled (62 AngioSeal, 60 Femostop). Patients in the AngioSeal group took longer to be removed from the angiography table (11 +/- 4 vs. 9 +/- 3 min; P = 0.002) compared with the Femostop group. Time to hemostasis (0.4 +/- 1.1 vs. 6.4 +/- 1.7 hr; P < 0.001) and ambulation (17 +/- 8 vs. 22 +/- 13 hr; P = 0.004) were less in the AngioSeal group, although time to discharge was not different. Nursing and medical officer time was no different. Disposables including device cost were higher in the AngioSeal group (209 dollars +/- 13 vs. 53 dollars +/- 9; P < 0.001). On a Visual Analogue scale, patients reported more pain at 4 hr (P < 0.001) and 8 hr (P < 0.001) in the Femostop group. The worst amount of pain at any time point was also more severe in the Femostop group (P < 0.001). Similar results were found on a Present Pain Intensity scale of pain. There were no differences in ultrasound-determined vascular complications (two each). Femoral access site closure using the AngioSeal device resulted in a small delay in leaving the angiography suite and a higher disposable cost compared to using the Femostop device. However, patients receiving the AngioSeal were able to ambulate sooner and reported less pain, which may justify the increased costs involved.

Do research interviews cause distress or interfere in management? Experience from a study of cancer patients

Research interviews with seriously ill patients are now often undertaken in quality of life research. Clinicians may be approached by researchers wishing to study their patients, and may be worried at some ethical aspects of interviewing. Concerns may include potential distress which interviews may cause, that they may interfere with the doctor-patient relationship, and perhaps, a scepticism that techniques addressing psychosocial concerns produce only 'soft' data. However, interview methods are a valuable tool for medical sociologists, nurse researchers and others. We discuss here some reflections following a study that involved interviewing severely ill patients with incurable malignant cerebral glioma. We use our observations to answer concerns and to discuss problems that arose. We suggest areas researchers and clinicians might consider before embarking on such collaboration.

Does a dedicated discharge coordinator improve the quality of hospital discharge?

OBJECTIVE

To evaluate the effectiveness of the role of a discharge coordinator whose sole responsibility was to plan and coordinate the discharge of patients from medical wards.

DESIGN

An intervention study in which the quality of discharge planning was assessed before and after the introduction of a discharge coordinator. Patients were interviewed on the ward before discharge and seven to 10 days after being discharged home.

SETTING

The three medical wards at the Homerton Hospital in Hackney, East London.

PATIENTS

600 randomly sampled adult patients admitted to the medical wards of the study hospital, who were resident in the district (but not in institutions), were under the care of physicians (excluding psychiatry), and were discharged home from one of the medical wards. The sampling was conducted in three study phases, over 18 months.

INTERVENTIONS

Phase I comprised base line data collection; in phase II data were collected after the introduction of the district discharge planning policy and a discharge form (checklist) for all patients; in phase III data were collected after the introduction of the discharge coordinator.

MAIN MEASURES

The quality and out come of discharge planning. Readmission rates, duration of stay, appropriateness of days of care, patients' health and satisfaction, problems after discharge, and receipt of services.

RESULTS

The discharge coordinator resulted in an improved discharge planning process, and there was a reduction in problems experienced by patients after discharge, and in perceived need for medical and healthcare services. There was no evidence that the discharge coordinator resulted in a more timely or effective provision of community services after discharge, or that the appropriateness or efficiency of bed use was improved.

CONCLUSIONS

The introduction of a discharge coordinator improved the quality of discharge planning, but at additional cost.

Resolution of left atrial spontaneous echocardiographic contrast after percutaneous mitral valvuloplasty: implications for thromboembolic risk

Left atrial spontaneous echocardiographic contrast (SEC) is an important marker of increased thromboembolic risk in patients with mitral stenosis. To evaluate the effect of percutaneous transseptal mitral valvuloplasty (PTMV) on SEC, we performed transesophageal echocardiography 1 day before and 3 months after PTMV on 88 consecutive patients. SEC was present in 65 (74%) patients before PTMV and was associated with absence of moderate or severe mitral regurgitation (p = 0.01), a smaller valve area (p = 0.02), an older age (p = 0.04), and atrial fibrillation (p = 0.05). At 3 months, PTMV resulted in a mean absolute and relative increase in valve area of 0.54 +/- 0.36 cm2 and 53% +/- 43%, respectively. SEC resolved in 37 patients but persisted in 28 (32%) patients at the 3-month study. The absolute and relative increase of valve area and worsened mitral regurgitation after PTMV were predictors of resolution of SEC, with the relative increase in valve area being the only significant predictor on multivariate analysis. PTMV frequently results in resolution of SEC, which may have important implications in reducing the thromboembolic risk in these patients.

Content of a discharge summary from a medical ward: views of general practitioners and hospital doctors

The objective of this study was to seek the views of general practitioners (GPs), hospital physicians and junior hospital doctors about the relative value of different items of clinical information in discharge summaries from medical wards, and so form a minimum and recommended data set for the purposes of clinical audit. GPs were selected randomly from five family health services authorities in England, and hospital consultants and junior hospital doctors were randomly selected from all 14 former health regions. Postal questionnaires were then sent to a sample of 400 GPs, 400 hospital consultants and 400 junior hospital doctors. The results have been tabulated. 'Details of drugs at discharge' (including frequency, dosage and proposed length of treatment), 'significant results of investigations, both positive and negative', 'suggested or made arrangements for follow up', and 'information given to patient about diagnosis' were ranked particularly high by all three groups of respondents.

Prognostic implications of left atrial spontaneous echo contrast in nonvalvular atrial fibrillation

OBJECTIVES

This study examined the influence of left atrial spontaneous echo contrast on the subsequent stroke or embolic event rate and on survival in patients with nonvalvular atrial fibrillation.

BACKGROUND

Left atrial spontaneous echo contrast is associated with atrial fibrillation and a history of previous stroke or other embolic events. However, the prognostic implications of spontaneous contrast in patients with nonvalvular atrial fibrillation are unknown.

METHOD

The study group comprised 272 consecutive patients with nonvalvular atrial fibrillation undergoing transesophageal echocardiography. Clinical and echocardiographic data were collected at baseline, and patients were prospectively followed up, and all strokes, other embolic events and deaths were documented. The relation between spontaneous contrast at baseline and subsequent stroke, other embolic events and survival was analyzed.

RESULTS

Left atrial spontaneous echo contrast was detected at baseline in 161 patients (59%). The mean follow-up was 17.5 months. The stroke or other embolic event rate was 12%/year (15 strokes, 3 transient ischemic attacks, 2 peripheral embolisms) in patients with, compared with 3%/year (5 strokes) in patients without, baseline spontaneous contrast (p = 0.002). In 149 patients without previous thromboembolism, the event rate was 9.5%/year in patients with and 2.2%/year in patients without spontaneous contrast (p = 0.003). There were 25 deaths in patients with and 11 deaths in patients without spontaneous contrast. Patients with spontaneous contrast had significantly reduced survival (p = 0.025). On multivariate analysis, spontaneous contrast was the only positive predictor (odds ratio 3.5, p = 0.03) and warfarin therapy on follow-up the only negative predictor (odds ratio 0.23, p = 0.02) of subsequent stroke or other embolic events.

CONCLUSIONS

Transesophageal echocardiography can risk stratify patients with nonvalvular atrial fibrillation by identifying left atrial spontaneous echo contrast. These patients have both a significantly higher risk of developing stroke or other embolic events and a reduced survival, and they may represent a subgroup in whom the risk/benefit ratio of anticoagulation may be most favorable.

Role of transoesophageal echocardiography in the diagnosis and management of aortic root abscess

OBJECTIVE

To assess and compare the roles of transthoracic and transoesophageal echocardiography in the diagnosis and management of an aortic root abscess.

DESIGN

To select patients with echocardiographic diagnosis of aortic valve endocarditis with and without an aortic root abscess and correlate this with a retrospective review of surgical and necropsy data.

SETTING

Tertiary referral centre at a university teaching hospital.

PATIENTS AND METHODS

34 patients with confirmed aortic valve endocarditis were treated over a four and a half year period. All patients underwent both transthoracic and transoesophageal echocardiography with 17 patients having biplane or multiplane imaging.

RESULT

11 patients (32%) had an aortic root abscess. Transthoracic echocardiography identified four cases of aortic root abscess whereas transoesophageal echocardiography correctly detected all 11 cases and also detected complications including mitral aortic intervalvar fibrosa fistula in two patients and right atrial involvement in another two patients. Only biplane imaging was able to show an anterior aortic root abscess in one patient and the circumferential involvement of the aortic annulus in another two patients. All patients with an aortic root abscess were treated surgically after transoesophageal echocardiographic diagnosis. After operation, prosthetic aortic regurgitation was present in seven patients and a repeat operation was performed in three patients. Only transoesophageal echocardiography detected a postoperative aorto-right atrial fistula in two patients and recurrence of the root abscess in another. There were five deaths in hospital (45%).

CONCLUSIONS

Compared with transthoracic echocardiography, transoesophageal echocardiography was more sensitive and more specific for the early diagnosis of aortic root abscess and its complications and facilitated both the preoperative and postoperative management of these patients. Biplane and multiplane imaging provide additional diagnostic information. All patients with suspected aortic valve endocarditis should have an early transoesophageal echocardiographic study.

Evaluation of transesophageal echocardiography before cardioversion of atrial fibrillation and flutter in nonanticoagulated patients

This study prospectively evaluated the role of transesophageal echocardiography (TEE) in screening for atrial thrombi before electrical cardioversion in 40 nonanticoagulated patients with nonvalvular atrial fibrillation (n = 33) or atrial flutter (n = 7). Transthoracic echocardiography did not detect atrial thrombus in any patient. TEE detected left atrial appendage thrombi in five patients (12%, p = 0.03), significantly associated with left ventricular systolic dysfunction (p = 0.02) and left atrial spontaneous echo contrast (p = 0.04). Cardioversion was cancelled in the five patients with thrombi and in two patients with spontaneous reversion before planned cardioversion. Cardioversion was successful in 25 (76%) of the 33 remaining patients. Cerebral embolism occurred 24 hours after successful cardioversion in one patient with atrial fibrillation and left ventricular dysfunction, who had left atrial spontaneous echo contrast, but no thrombus was detected by TEE before cardioversion. Repeat TEE after embolism showed a fresh left atrial appendage thrombus and increased left atrial spontaneous echo contrast. These results indicate that TEE improves the detection of left atrial appendage thrombi in candidates for cardioversion, in whom the procedure may be deferred. However, the exclusion by TEE of preexisting atrial thrombi before cardioversion does not eliminate the risk of embolism after cardioversion because of persistent atrial stasis and de novo thrombosis.

Hematologic correlates of left atrial spontaneous echo contrast and thromboembolism in nonvalvular atrial fibrillation

OBJECTIVES

This study examined the relation between left atrial spontaneous echo contrast, hematologic variables and thrombo-embolism in patients with nonvalvular atrial fibrillation.

BACKGROUND

Left atrial spontaneous echo contrast is associated with left atrial stasis and thromboembolism in patients with nonvalvular atrial fibrillation. However, its hematologic determinants in patients with nonvalvular atrial fibrillation are unknown.

METHODS

Clinical, hematologic and echocardiographic variables were prospectively measured in 135 consecutive patients with nonvalvular atrial fibrillation undergoing transesophageal echocardiography.

RESULTS

Patients with left atrial spontaneous echo contrast (n = 74, 55%) had an increased fibrinogen concentration (p = 0.029), platelet count (p = 0.045), hematocrit (p = NS) and left atrial dimension (p = 0.005). Multivariate analysis showed that left atrial spontaneous echo contrast was independently related to hematocrit (odds ratio = 2.24, p = 0.002), fibrinogen concentration (odds ratio = 2.08, p = 0.008) and left atrial dimension (odds ratio = 1.90, p = 0.004) but not platelet count. It was also associated with left atrial thrombus (n = 15, p = 0.001) and with recent embolism (n = 40, p < 0.001). In 40 clinically stable outpatients without previous embolism, left atrial spontaneous echo contrast was significantly related to hematocrit (p = 0.005), fibrinogen concentration (p = 0.035) and left atrial dimension (p = 0.029) but not to coagulation factor VII, D-dimer, erythrocyte sedimentation rate, platelet count, plasma beta-thromboglobulin, plasma glycocalicin or glycocalicin index.

CONCLUSIONS

Left atrial spontaneous echo contrast in patients with nonvalvular atrial fibrillation is independently related to hematocrit, fibrinogen concentration and left atrial dimension, indicating a relatively hypercoagulable state in addition to stasis. These findings support the hypothesis that left atrial spontaneous echo contrast is due to erythrocyte aggregation. Hematologic factors may contribute to its association with thromboembolism.

Role of transoesophageal echocardiography in evaluation of cardiogenic embolism

OBJECTIVE

To determine the value of transoesophageal echocardiography in the assessment of selected patients at risk of cardiogenic embolism or after it.

DESIGN

Prospective comparison of the results of transoesophageal and transthoracic echocardiography. Transoesophageal echocardiography was performed with a 5 MHz single plane phased array transducer.

SETTING

University teaching hospital.

PATIENTS

100 patients referred for transoesophageal echocardiography after a cerebral ischaemic event or peripheral arterial embolism (n = 63), before percutaneous balloon dilatation of the mitral valve (n = 23), or before electrical cardioversion of atrial fibrillation (n = 14).

RESULTS

Transthoracic echocardiography showed potential sources of embolism in four patients including left ventricular thrombus in two patients (with one false positive), left atrial appendage thrombus (n = 1), and patent foramen ovale (n = 1). Transoesophageal echocardiography showed 59 potential embolic sources in 45 patients including left atrial spontaneous echo contrast (n = 33), left atrial appendage thrombus (n = 13), left ventricular thrombus (n = 5), patent foramen ovale (n = 3), left ventricular spontaneous echo contrast (n = 2), mitral valve prosthesis thrombus (n = 1), mitral valve prolapse (n = 1), and pronounced aortic atheroma (n = 1). Transoesophagal echocardiography showed potential embolic sources in 36/53 (68%) patients with atrial fibrillation compared with 9/47 (19%) patients in sinus rhythm. Percutaneous balloon dilatation of the mitral valve was performed without embolic complications in 18 patients without left atrial thrombi and in three patients with small fixed thrombi in the left atrial appendage. It was cancelled in two patients with large thrombi in the left atrial appendage. Cardioversion was performed without embolic complications in 14 patients without left atrial thrombi.

CONCLUSIONS

Transoesophageal echocardiography detects potential sources of embolism better than transthoracic echocardiography in selected patients at risk of cardiogenic embolism or after it.

Left atrial spontaneous echo contrast: a clinical and echocardiographic analysis

The clinical and echocardiographic variables related to left atrial spontaneous echo contrast were prospectively evaluated in a consecutive series of 400 patients undergoing transesophageal echocardiography with a 5-MHz single plane transducer. Left atrial spontaneous echo contrast was found in 75 patients (19%) and was significantly associated with atrial fibrillation, mitral stenosis, absence of mitral regurgitation, increased left atrial dimension and a history of suspected embolism. Seventy-one (95%) of the patients with spontaneous echo contrast had atrial fibrillation or mitral stenosis. Anticoagulant therapy had no significant association with spontaneous echo contrast. Multivariate analysis in 89 patients with mitral stenosis or mitral valve replacement showed that spontaneous echo contrast was the only independent predictor (p = 0.03) of left atrial thrombus or suspected embolism, or both. In 60 patients with atrial fibrillation of nonvalvular origin, spontaneous echo contrast (p = 0.01) and age (p = 0.03) were the only independent predictors of left atrial thrombus or suspected embolism, or both. It is concluded that left atrial spontaneous echo contrast is 1) a common finding in patients undergoing transesophageal echocardiography, 2) associated with conditions favoring stasis of left atrial blood, and 3) a marker of previous thromboembolism in patients with nonvalvular atrial fibrillation and those with mitral stenosis or mitral valve replacement.

Doppler echocardiographic determination of aortic valve area using the continuity equation

The noninvasive measurement of aortic valve area by use of the continuity equation has been proposed as an accurate method for determining the severity of aortic stenosis. In 32 patients (mean age 64 +/- 14 years) with proven aortic stenosis and without significant regurgitation, aortic valve areas derived by the Gorlin equation from cardiac catheterisation data were compared with valve areas calculated from the continuity equation using Doppler echocardiography. There was a close correlation between Doppler and catheter derived aortic valve areas (r = 0.87, SEE = 0.17 cm2). The interobserver error for aortic valve area measurement in 20 patients was 9.0 +/- 6.8%. The specificity of this method for critical aortic stenosis (aortic valve area less than 0.75 cm2) was 73% and the sensitivity 88%. We conclude that in an adult, predominantly elderly population with calcific aortic stenosis, this Doppler echocardiographic method is reproducible and can be used accurately to derive aortic valve area.

Low molecular weight measles immunoglobulin M in subacute sclerosing panencephalitis and acute measles

Thirty eight patients with subacute sclerosing panencephalitis (SSPE) were investigated. Five patients who previously had measles immunoglobulin M (IgM) detected in unfractionated serum and cerebrospinal fluid (CSF) had measles IgM exclusively in the low molecular weight (LMW) fractions of serum and CSF. Measles IgM had previously not been found in unfractionated serum from 33 patients but was detected exclusively in the LMW fractions of serum from 30 patients. Seven children with acute measles had the expected high molecular weight (HMW) measles IgM in serum but 5 also had LMW measles IgM. Four young adults who had had measles in childhood had neither HMW nor LMW measles IgM in their sera.

Social dimensions of healing: a longitudinal study of outcomes of medical management of headaches

The social sciences have made few direct empirical contributions to the understanding of 'non-specific' benefits of treatment and generally the symbolic healing of indigenous non-Western medicine has received most attention in this field. This paper reports some results of a wider study of neurological clinics in England in which it is shown that a sample attending for headaches experienced considerable improvement in symptoms when followed up 1 year after attendance. Most of this improvement appeared not to be due to any intended treatments received at the clinics but could be attributed to the quality of patients' immediate responses to clinic attendance as assessed from reach interviews conducted after their consultations. This relationship between immediate 'satisfied' response and subsequent symptomatic improvement is interpreted in terms of the general levels of expectancy and sense of potential control achieved by obtaining referral to a specialist which directly enhanced recovery in those patients who felt the doctor's actions to be directly relevant to their personal concerns. Disappointment with the doctor reduced the 'non-specific' therapeutic benefits of the hospital referral. The intimate connections of patient satisfaction, treatment received and subsequent outcomes need more careful consideration in social studies of Western medicine.

Spinal myoclonus

A case of rhythmic myoclonus affecting only the lower part of the body is described. This occurred as an acute self-limiting illness. The changes in the cerebrospinal fluid (CSF) suggested a viral infection. Clinical and electrophysiological findings indicated that the involuntary movements were arising at spinal level and were independent of suprasegmental influences. There are few previously reported cases of spinal myoclonus, all different in various respects from the present one, which is reminiscent of the results of experimental inoculation of virus into feline spinal cord.

The pathology of experimental lead encephalopathy in the baboon (Papio anubis)

Hopkins, A. P., and Dayan, A. D. (1974).British Journal of Industrial Medicine,31, 128-133. The pathology of experimental lead encephalopathy in the baboon (Papio anubis). Baboons(Papio anubis) were intoxicated by intratracheal injections of lead carbonate. The main pathological findings were of widespread cerebral oedema and focal cortical necroses. The mechanism by which lead produces these changes is not known.

Conduction in unmyelinated fibres in experimental neuropathy

Conduction velocity of autonomic unmyelinated fibres has been measured in the cervical sympathetic trunk of normal rats, and in rats intoxicated by acrylamide or by isoniazid. The mean maximal conduction velocity in nerves from normal rats is 2·0 m/sec. There is no significant reduction in velocity of the unmyelinated fibres in nerves from intoxicated rats, although histological studies of the sural nerve confirmed severe degeneration of myelinated fibres in the same animals. It is shown that the amplitude of the compound nerve action potential is proportional to the resistance between the recording electrodes. If this is taken into account, there is no reduction in the amplitude of the monophasic action potential of unmyelinated fibres recorded from the cervical sympathetic trunk of intoxicated rats. The amplitude of the A component of the sural nerve compound action potential is markedly reduced in rats intoxicated by acrylamide or by isoniazid, but there is no significant reduction in the amplitude of the C component in the same nerve. It is concluded that in the rat an insignificant number of unmyelinated fibres of autonomic or dorsal root origin are affected in the neuropathy produced by acrylamide or isoniazid. The relevance of these findings to human neuropathies is discussed.

Motor and sensory nerve conduction velocity in the baboon: normal values and changes during acrylamide neuropathy

Nerve conduction velocity and the amplitude of nerve and muscle action potentials have been measured in the median and anterior tibial nerves of normal adult and infant baboons. The effect of altered temperature on velocity has also been investigated. Seven adult baboons were intoxicated with acrylamide. In animals given 10-15 mg/kg/day, the gradual development of a peripheral neuropathy was accompanied by a decline in the amplitude of both muscle and nerve action potentials. There was also a gradual fall in conduction velocity. In some cases maximal motor velocity in the median nerve fell by as much as 34%, and in the anterior tibial nerve by as much as 49%, the largest falls being seen in animals showing the greatest reductions in response amplitude. Histological studies, reported elsewhere, have shown that the main pathological change in our animals was a degeneration of the peripheral nerves, with little demyelination. Fibre diameter histograms indicated that large fibres were particularly severely affected, and it seems likely that the reduced maximal conduction velocities were due to this selective loss of large-diameter fibres.

The effect of local pressure in diphtheritic neuropathy

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