Use of fax facility improves decision making regarding thrombolysis in acute myocardial infarction.

BACKGROUND: Electrocardiography is the fundamental investigation for decision making regarding thrombolytic treatment in acute myocardial infarction (MI). Increasing the accuracy of ECG analysis by input from consultant staff may assist in management decisions in patients with suspected MI. AIMS: To evaluate a system whereby out of hours ECGs can be faxed to the consultant to aid in decision making regarding thrombolytic treatment. METHODS: 112 patients with suspected MI were assessed on admission by the senior house officer (SHO) who faxed to a cardiology consultant the ECG trace and a predesigned form with information on: clinical assessment of the patient; interpretation of the ECG; and views regarding administration of thrombolytic treatment including choice of agent. The consultant reviewed the information and communicated his views to the SHO. Subsequent diagnosis was recorded in all patients and the forms were analysed in regard to areas of agreement and disagreement between the SHO and the consultant. RESULTS: A diagnosis of MI was confirmed in 52 of the 112 patients (46.4%). The consultant agreed with the SHO's decision on thrombolysis in 98 patients (87.5%). The reason for disagreement in the remaining 14 patients (12.5%) was SHO misinterpretation of the ECG (10 patients) and clinical assessment (four patients). Eight patients were saved unnecessary thrombolytic treatment and four received it when they otherwise would not have. Additionally the choice of thrombolytic agent was changed in six patients from streptokinase to tissue plasminogen activator. CONCLUSION: The use of fax machine assists in decision making with regard to thrombolytic treatment and provides support to junior doctors in what can be a difficult, yet critical decision.

Assessment of the active compression-decompression device (ACD) in cardiopulmonary resuscitation using transoesophageal echocardiography.

Transoesophageal echocardiography was used to investigate the haemodynamic profile achieved during active compression-decompression cardiopulmonary resuscitation in humans. The mechanism of antegrade blood flow achieved by ACD-CPR is consistent with the cardiac pump theory. Improved right heart compression, antegrade blood flow patterns and left ventricular filling were observed in some patients during ACD-CPR.

Home or hospital care for acute myocardial infarction? A survey of general practitioners' attitudes in the thrombolytic era.

This study examines the issue of whether to give home or hospital care to patients with suspected myocardial infarction now that the value of thrombolytic therapy has been recognized. A questionnaire survey of 69 general practitioners showed that the majority were aware of the potential benefits of thrombolysis although few thought that these extended beyond six hours after the onset of symptoms. Most would opt for hospital care for patients under the age of 70 years, but would treat older patients with uncomplicated myocardial infarctions at home, depriving them of the opportunity to receive thrombolysis. The admission policies of general practitioners for patients with suspected myocardial infarction merit reappraisal so that thrombolysis can be considered for all patients up to 24 hours after the onset of symptoms.

The detection of fat embolism by transoesophageal echocardiography during reamed intramedullary nailing. A study of 24 patients with femoral and tibial fractures.

We performed transoesophageal echocardiography on 24 patients during reamed intramedullary nailing of 17 tibial and seven femoral fractures. In 14 patients there was only minimal evidence of emboli passing through the heart, but in six copious showers of small emboli (< 10 mm maximum dimension) were observed. In four other patients, there were also multiple large emboli (> 10 mm maximum dimension). Three of these patients developed fat embolism syndrome postoperatively and one died. Earlier nailing was associated with smaller quantities of emboli.

Echocardiography of transatrial embolism during cemented and uncemented hemiarthroplasty of the hip.

We performed transoesophageal echocardiography on 20 patients with femoral neck fractures randomly treated with an uncemented Austin-Moore or cemented Hastings hemiarthroplasty. Cemented arthroplasty caused greater and more prolonged embolic cascades than did uncemented arthroplasty. Some emboli were more than 3 cm in length. In some patients the cascades were associated with pulmonary hypertension, diminished oxygen tension and saturation, and the presence of fat and marrow in aspirates from the right atrium.

Transcardiac echocardiography during invasive intramedullary procedures.

We performed transoesophageal echocardiography in 111 operations (110 patients) which included medullary reaming for fresh fractures of the femur and tibia, pathological lesions of the femur, and hemiarthroplasty of the hip. Embolic events of varying intensity were seen in 97 procedures and measured pulmonary responses correlated with the severity of embolic phenomena. Twenty-four out of the 25 severe embolic responses occurred while reaming pathological lesions or during cemented hemiarthroplasty of the hip and, overall, pathological lesions produced the most severe responses. Paradoxical embolisation occurred in four patients, all with pathological lesions of the femur (21%); two died. In 12 patients large coagulative masses became trapped in the heart. Extensive pulmonary thromboembolism with reamed bone and immature clot was found at post-mortem in two patients; there was severe systemic embolisation of fat and marrow in one who had a patent foramen ovale and widespread mild systemic fat embolisation in the other without associated foraminal defect. Sequential analysis of blood from the right atrium in five patients showed considerable activation of clotting cascades during reaming.

Effect of "fast track" admission for acute myocardial infarction on delay to thrombolysis.

OBJECTIVE: To evaluate the impact of a fast track triage system for patients with acute myocardial infarction. DESIGN: Comparison of delays in admission to hospital and in receiving thrombolytic treatment before and after introducing fast track system with delays recorded in 1987-8. Patients fulfilling clinical and electrocardiographic criteria for myocardial infarction were selected for rapid access to the cardiac care team, bypassing evaluation by the medical registrar. SETTING: Major accident and emergency, cardiac and trauma centre. SUBJECTS: 359 patients admitted to the cardiac care unit during 1 February to 31 July 1990 with suspected acute infarction. MAIN OUTCOME MEASURES: Accuracy of diagnosis and delay from arrival at hospital to thrombolytic treatment. RESULTS: 248 of the 359 patients had myocardial infarction confirmed, of whom 127 received thrombolytic treatment. The fast track system correctly identified 79 out of 127 (62%) patients who subsequently required thrombolytic treatment. 95% (79/83) of patients treated with thrombolysis after fast track admission had the diagnosis confirmed by electrocardiography and enzyme analysis. The median delay from hospital admission to thrombolytic treatment fell from 93 minutes in 1987-8 to 49 minutes in fast track patients (p less than 0.001). Delay in admission to the cardiac care unit was reduced by 47% for fast tract patients (median 60 minutes in 1987-8 v 32 minutes in 1990, p less than 0.001) and by 25% for all patients (60 minutes v 45 minutes, p less than 0.001). CONCLUSION: This fast track system requires no additional staff or equipment, and it halves inhospital delay to thrombolytic treatment without affecting the accuracy of diagnosis among patients requiring thrombolysis.

Effect of socioeconomic deprivation on waiting time for cardiac surgery: retrospective cohort study.

OBJECTIVE: To determine whether the priority given to patients referred for cardiac surgery is associated with socioeconomic status. DESIGN: Retrospective study with multivariate logistic regression analysis of the association between deprivation and classification of urgency with allowance for age, sex, and type of operation. Multivariate linear regression analysis was used to determine association between deprivation and waiting time within each category of urgency, with allowance for age, sex, and type of operation. SETTING: NHS waiting lists in Scotland. PARTICIPANTS: 26 642 patients waiting for cardiac surgery, 1 January 1986 to 31 December 1997. MAIN OUTCOME MEASURES: Deprivation as measured by Carstairs deprivation category. Time spent on NHS waiting list. RESULTS: Patients who were most deprived tended to be younger and were more likely to be female. Patients in deprivation categories 6 and 7 (most deprived) waited about three weeks longer for surgery than those in category 1 (mean difference 24 days, 95% confidence interval 15 to 32). Deprived patients had an odds ratio of 0.5 (0.46 to 0.61) for having their operations classified as urgent compared with the least deprived, after allowance for age, sex, and type of operation. When urgent and routine cases were considered separately, there was no significant difference in waiting times between the most and least deprived categories. CONCLUSIONS: Socioeconomically deprived patients are thought to be more likely to develop coronary heart disease but are less likely to be investigated and offered surgery once it has developed. Such patients may be further disadvantaged by having to wait longer for surgery because of being given lower priority.

Comparison of mass and targeted screening strategies for cardiovascular risk: simulation of the effectiveness, cost-effectiveness and coverage using a cross-sectional survey of 3921 people.

BACKGROUND: Cardiovascular primary prevention should be targeted at those with the highest global risk. However, it is unclear how best to identify such individuals from the general population. The aim of this study was to compare mass and targeted screening strategies in terms of effectiveness, cost effectiveness and coverage. METHODS: The Scottish Health Survey provided cross-sectional data on 3921 asymptomatic members of the general population aged 40-74 years. We undertook simulation models of five screening strategies: mass screening, targeted screening of deprived communities, targeted screening of family members and combinations of the latter two. RESULTS: To identify one individual at high risk of premature cardiovascular disease using mass screening required 16.0 people to be screened at a cost of pound370. Screening deprived communities targeted 17% of the general population but identified 45% of those at high risk, and identified one high-risk individual for every 6.1 people screened at a cost of pound141. Screening family members targeted 28% of the general population but identified 61% of those at high risk, and identified one high-risk individual for every 7.4 people screened at a cost of pound170. Combining both approaches enabled 84% of high risk individuals to be identified by screening only 41% of the population. Extending targeted to mass screening identified only one additional high-risk person for every 58.8 screened at a cost of pound1358. CONCLUSIONS: Targeted screening strategies are less costly than mass screening, and can identify up to 84% of high-risk individuals. The additional resources required for mass screening may not be justified.

Secondhand smoke exposure and survival following acute coronary syndrome: prospective cohort study of 1261 consecutive admissions among never-smokers.

OBJECTIVE: To determine whether exposure to secondhand smoke is associated with early prognosis following acute coronary syndrome. DESIGN, SETTING AND PARTICIPANTS: We interviewed consecutive patients admitted to nine Scottish hospitals over 23 months. Information was obtained, via questionnaire, on age, sex, smoking status, postcode of residence and admission serum cotinine concentration was measured. Follow-up data were obtained from routine hospital admission and death databases. RESULTS: Of the 5815 participants, 1261 were never-smokers. Within 30 days, 50 (4%) had died and 35 (3%) had a non-fatal myocardial infarction. All-cause deaths increased from 10 (2.1%) in those with cotinine < or =0.1 ng/ml to 22 (7.5%) in those with cotinine >0.9 ng/ml (chi(2) test for trend p<0.001). This persisted after adjustment for potential confounders (cotinine >0.9 ng/ml: adjusted OR 4.80, 95% CI 1.95 to 11.83, p = 0.003). The same dose response was observed for cardiovascular deaths and death or myocardial infarction. CONCLUSIONS: Secondhand smoke exposure is associated with worse early prognosis following acute coronary syndrome. Non-smokers need to be protected from the harmful effects of secondhand smoke.

Hospital volume of throughput and periprocedural and medium-term adverse events after percutaneous coronary intervention: retrospective cohort study of all 17,417 procedures undertaken in Scotland, 1997-2003.

OBJECTIVE: To determine whether percutaneous coronary intervention (PCI) hospital volume of throughput is associated with periprocedural and medium-term events, and whether any associations are independent of differences in case mix. DESIGN: Retrospective cohort study of all PCIs undertaken in Scottish National Health Service hospitals over a six-year period. METHODS: All PCIs in Scotland during 1997-2003 were examined. Linkage to administrative databases identified events over two years' follow up. The risk of events by hospital volume at 30 days and two years was compared by using logistic regression and Cox proportional hazards models. RESULTS: Of the 17,417 PCIs, 4900 (28%) were in low-volume hospitals and 3242 (19%) in high-volume hospitals. After adjustment for case mix, there were no significant differences in risk of death or myocardial infarction. Patients treated in high-volume hospitals were less likely to require emergency surgery (adjusted odds ratio 0.18, 95% confidence interval (CI) 0.07 to 0.54, p = 0.002). Over two years, patients in high-volume hospitals were less likely to undergo surgery (adjusted hazard ratio 0.52, 95% CI 0.35 to 0.75, p = 0.001), but this was offset by an increased likelihood of further PCI. There was no net difference in coronary revascularisation or in overall events. CONCLUSION: Death and myocardial infarction were infrequent complications of PCI and did not differ significantly by volume. Emergency surgery was less common in high-volume hospitals. Over two years, patients treated in high-volume centres were as likely to undergo some form of revascularisation but less likely to undergo surgery.

Delays in admission of patients with acute myocardial infarction to coronary care: implications for thrombolysis.

Of 408 patients presenting to a coronary care unit over a six month period 237 had an acute myocardial infarction. Two-thirds presented to hospital within three hours of the onset of symptoms. The median delay between arrival in hospital and admission to the Coronary Care Unit was 60 minutes. Only a minority of patients with acute myocardial infarction were eligible to receive thrombolysis, the most common exclusion criteria being an electrocardiograph that was not diagnostic of infarction at presentation. In-hospital transfer delay has increased considerably since 1972. It did not exclude many patients from receiving thrombolysis but it caused delayed thrombolysis.

The interface of hypertension and ischemic heart disease.

Myocardial infarction remains the single most common cause of death in patients with essential hypertension. This becomes particularly evident when the hypertension is associated with left ventricular hypertrophy. To combat the continuing high mortality from myocardial infarction in hypertensive heart disease, however, all aspects of the relationship must be studied. Thus, addressing the interface from an epidemiological standpoint as well as from a pathological point is critical and progress in these areas as well as in areas of management are ultimately likely to lead to a fall in morbidity and mortality from ischemic heart disease in patients with hypertension.

Gastric antral vascular ectasia: a problem of recognition and diagnosis.

Gastric antral vascular ectasia ('water melon stomach') is a poorly documented cause of occult upper gastrointestinal blood loss. We describe a case which emphasises the clinical and pathological difficulties that can be encountered in making this elusive diagnosis.

The use of coaxially aligned freeze-thawed skeletal muscle autografts in the repair of the cauda equina--in the sheep.

The aim was to develop a model for study of nerve regeneration in nerve roots above the level of the dorsal root ganglion and to investigate the use of freeze-thawed muscle autografts for repair of nerve roots at this level. Four adult sheep were used for the experiment. A laminectomy was performed at the lumbosacral junction and the S2 root identified. Both the dorsal and ventral S2 roots were divided unilaterally within the dura and a freeze-thawed muscle graft was inserted into the nerve gap. When assessed at 6 months an action potential was recordable from the ventral root in one sheep. Histological examination of the nerve roots showed evidence of regeneration across the graft in the ventral roots of all the sheep and the dorsal roots of some. This preliminary work indicates a capacity for regeneration of the cauda equina and that freeze-thawed muscle can support this. It provides a useful model for further study of nerve root repair.

Changes in the anterior chamber of the eye during acute hypoglycaemia in humans.

1. The changes in the volume and depth of the anterior chamber of the eye during acute insulin-induced hypoglycaemia were examined in nine healthy non-diabetic subjects (aged 23-31 years). The dimensions of the anterior chamber of the eye were measured by a photogrammetric technique, with Polaroid photographs taken of the lower half of the mid-sagittal plane of the eye at an angle of 55 degrees at a magnification of x16. Photographs were taken before and at regular intervals after the induction of acute hypoglycaemia using an infusion of unmodified (soluble) insulin at 2.5 m-units min-1 kg-1. Plasma adrenaline was measured regularly throughout the study. 2. Plasma glucose fell from 4.5 +/- 0.2 mmol/l (mean +/- SEM) to a nadir of 1.0 +/- 0.1 mmol/l (P < 0.01), which coincided with the onset of the acute autonomic reaction. Plasma adrenaline rose from 0.3 +/- 0.1 nmol/l to a peak of 3.2 +/- 0.6 nmol/l (P < 0.01) at 15 min after the autonomic reaction. 3. The volume of the anterior chamber decreased by 8.2% from 284.7 +/- 21.5 microliters at baseline to 264.5 +/- 17.0 microliters (P < 0.01) at the onset of the autonomic reaction. No significant alteration in axial anterior chamber depth was evident, but peripheral anterior depth decreased from 2.25 +/- 0.20 mm at baseline to 2.07 +/- 0.14 mm (P < 0.05) at the onset of the autonomic response.(ABSTRACT TRUNCATED AT 250 WORDS)