Coordination between proteasome impairment and caspase activation leading to TAU pathology: neuroprotection by cAMP

Neurofibrillary tangles (NFTs) are hallmarks of Alzheimer's disease (AD). The main component of NFTs is TAU, a highly soluble microtubule-associated protein. However, when TAU is cleaved at Asp421 by caspases it becomes prone to aggregation leading to NFTs. What triggers caspase activation resulting in TAU cleavage remains unclear. We investigated in rat cortical neurons a potential coordination between proteasome impairment and caspase activation. We demonstrate that upon proteasome inhibition, the early accumulation of detergent-soluble ubiquitinated (SUb) proteins paves the way to caspase activation and TAU pathology. This occurs with two drugs that inhibit the proteasome by different means: the product of inflammation prostaglandin J2 (PGJ2) and epoxomicin. Our results pinpoint a critical early event, that is, the buildup of SUb proteins that contributes to caspase activation, TAU cleavage, TAU/Ub-protein aggregation and neuronal death. Furthermore, to our knowledge, we are the first to demonstrate that elevating cAMP in neurons with dibutyryl-cAMP (db-cAMP) or the lipophilic peptide PACAP27 prevents/diminishes caspase activation, TAU cleavage and neuronal death induced by PGJ2, as long as these PGJ2-induced changes are moderate. db-cAMP also stimulated proteasomes, and mitigated proteasome inhibition induced by PGJ2. We propose that targeting cAMP/PKA to boost proteasome activity in a sustainable manner could offer an effective approach to avoid early accumulation of SUb proteins and later caspase activation, and TAU cleavage, possibly preventing/delaying AD neurodegeneration.

Randomized clinical trial of VNUS® ClosureFAST™ radiofrequency ablation versus laser for varicose veins

Background

Endovenous laser ablation (EVLA) and radiofrequency ablation (RFA) are both associated with excellent technical, clinical and patient-reported outcomes for the treatment of varicose veins. The aim of this study was to compare the techniques in a randomized clinical trial.

Methods

Consecutive patients with primary great saphenous vein reflux were randomized to EVLA (980 nm) or RFA (VNUS® ClosureFAST™) at a single centre. The primary outcome measure was postprocedural pain after 3 days. Secondary outcome measures were quality of life at 6 weeks, determined by the Aberdeen Varicose Vein Questionnaire (AVVQ) and Short Form 12 (SF-12®), and clinical improvement assessed by the Venous Clinical Severity Score (VCSS). Analyses were performed on the basis of intention to treat using multivariable linear regression.

Results

Some 131 patients were randomized to EVLA (64 patients) or RFA (67). Mean(s.d.) pain scores over 3 days were 26·4(22·1) mm for RFA and 36·8(22·5) mm for EVLA (P = 0·010). Over 10 days, mean(s.d.) pain scores were 22·0(19·8) mm versus 34·3(21·1) mm for RFA and EVLA respectively (P = 0·001). The mean(s.d.) number of analgesic tablets used was lower for RFA than for EVLA over 3 days (8·8(9·5) versus 14·2(10·7); P = 0·003) and 10 days (20·4(22·6) versus 35·9(29·4) respectively; P = 0·001). Changes in AVVQ, SF-12® and VCSS scores at 6 weeks were similar in the two groups: AVVQ (P = 0·887), VCSS (P = 0·993), SF-12® physical component score (P = 0·276) and mental component score (P = 0·449).

Conclusion

RFA using VNUS® ClosureFAST™ was associated with less postprocedural pain than EVLA. However, clinical and quality-of-life improvements were similar after 6 weeks for the two treatments. Registration number: ISRCTN66818013 (http://www.controlled-trials.com).

Alterations in Purinoceptor Expression in Human Long Saphenous Vein during Varicose Disease

OBJECTIVES

Varicose veins are dilated tortuous veins of varying tone. Purinergic signalling is important in the control of tone and in mediating trophic changes in blood vessels. The expression of P2 receptors in control and varicose veins will be examined.

METHODS

Purinergic signalling in circular and longitudinal smooth muscle of the human long saphenous vein was studied in control and varicose tissues using immunohistochemistry, organ bath pharmacology and electron microscopy.

RESULTS

P2X1, P2Y1, P2Y2, P2Y4 and P2Y6 receptors were present on circular and longitudinal smooth muscle. Purine-mediated circular and longitudinal muscle contractions were weaker in varicose veins. Electron microscopy and immunohistochemistry findings support the view that smooth muscle cells change from the contractile to synthetic phenotype in varicose veins, associated with an upregulation of P2Y1 and P2Y2 receptors and a down regulation of P2X1 receptors.

CONCLUSIONS

Down regulation of P2X1 receptors on the smooth muscle of varicose veins is associated with loss of contractile activity. Upregulation of P2Y1 and P2Y2 receptors is associated with a shift from contractile to synthetic and/or proliferative roles. The phenotype change in smooth muscle is associated with weakening of vein walls and may be a causal factor in the development of varicose veins.

Blood oxygen level-dependent (BOLD) magnetic resonance imaging in patients with dypiridamole induced ischaemia; a PET comparative study

BACKGROUND

Blood oxygen level-dependent (BOLD) MRI relies on changes in deoxyhaemoglobin level in tissues under stress for signal variation and may be used for detection of ischaemic myocardium.

METHODS

15 patients with stress induced myocardial ischaemia on PET scanning underwent rest and dypiridamole stress MRI using a double breath-hold T2-weighted, ECG gated sequence to produce BOLD contrast images and cine-MRI for wall thickening assessment. Signal change on BOLD MRI and wall thickening were compared between rest and stress images in ischaemic and non-ischaemic myocardial segments.

RESULTS

Using PET, 156 segments were identified with reversible ischaemia and 324 as non-ischaemic. The ischaemic segments were found on BOLD MRI to have an average signal change between rest and stress of -16.7% compared to -14% in the non-ischaemic segments (p=0.04). The average wall thickening was 7.8 mm in the ischaemic segments compared with 9.5 mm in the non-ischaemic segments (p<0.0001).

CONCLUSION

BOLD MRI with wall thickening assessment may differentiate ischaemic from non-ischaemic myocardium in patients with stress induced myocardial ischaemia. Larger studies with improved spatial resolution would help define a threshold for detection of ischaemia as well as determine this technique's sensitivity and specificity.

Sinus of Valsalva fistula with quadricuspid aortic valve, a first reported association

Quadricuspid aortic valve and sinus of Valsalva fistula are rare congenital anomalies. We report the first case of association of these two congenital anomalies in an adult patient and the important role of Magnetic Resonance Imaging (MRI) in establishing and confirming the correct diagnosis and helping in planning the treatment.

Benign complications of expandable metal stents used in the palliation of oesophageal carcinoma: two case reports

We describe two patients who were treated with self-expanding metal stent (SEMS) insertion as palliation of malignant oesophageal strictures. Both patients re-presented with dysphagia several months after SEMS insertion due to benign strictures. Initial treatment with balloon dilation and medical management had limited success so both patients had further SEMS inserted across the secondary benign strictures. This provided very good symptomatic relief. Chemotherapy and chemo-radiation in patients with inoperable oesophageal carcinoma are prolonging patient survival. As patients survival lengthens benign complications of SEMS may become an increasing clinical problem.

Automatic detection of coronary artery disease in myocardial perfusion SPECT using image registration and voxel to voxel statistical comparisons

The purpose of this study was to compare the performance of automatic detection of coronary artery disease (CAD) with that of expert observers. A male and female normal image template was constructed from normal stress technetium-99m single photon emission computed tomography (SPECT) studies. Mean and standard deviation images for each sex were created by registering normal studies to a standard shape and position. The test group consisted of 104 patients who had been routinely referred for SPECT and angiography. The gold standard for CAD was defined by angiography. The test group studies were registered to the respective templates and the Z-score was calculated for each voxel. Voxels with a Z-score greater than 5 indicated the presence of CAD. The performance of this method and that of three observers were compared by continuous receiver operating characteristic (CROC) analysis. The overall sensitivity and specificity for automatic detection were 73% and 92%, respectively. The area (Az) under the CROC curve (+/-1 SE) for automatic detection of CAD was 0.88+/-0.06. There was no statistically significant difference between the performances of the three observers in terms of Az and that of automatic detection (P> or =0.25, univariate Z-score test). The use of this automated statistical mapping approach shows a performance comparable with experienced observers, but avoids inter-observer and intra-observer variability.

Effects of warfarin therapy on plasma fibrinogen, von Willebrand factor, and fibrin D-dimer in left ventricular dysfunction secondary to coronary artery disease with and without aneurysms

Cardiac impairment in patients is associated with intracardiac thrombus formation and thromboembolism. A high prothrombotic state may exist in such patients, and abnormalities in plasma markers of thrombogenesis may be indicative of such a state. The aim of this study was to determine the associations of left ventricular (LV) aneurysm formation and dysfunction with plasma fibrinogen, von Willebrand factor, and fibrin D-dimer, which are markers associated with thrombus formation (thrombogenesis) and to investigate the effects of warfarin given to patients with LV aneurysms on fibrinogen and D-dimer levels. A cross-sectional study of 112 patients with coronary artery disease was initially performed: 34 patients had normal LV function (group 1); 30 had LV dysfunction without aneurysm formation (group 2); 29 had LV aneurysms without anticoagulation (group 3a); and 19 patients had LV aneurysms with warfarin therapy (group 3b). Results were compared with 158 population controls from a random population sample. A longitudinal study of 10 patients given warfarin was also performed. In group 1, plasma fibrinogen (median difference 0.36 g/L; p = 0.0009) and von Willebrand factor (median difference 17 IU/dl; p = 0.04) were elevated, whereas plasma D-dimer levels (median difference 23.0 ng/ml; p = 0.001) were lower than those in population control subjects. There were no significant differences in plasma fibrinogen, von Willebrand factor, or D-dimer levels between groups 1 and 2. In group 3a, plasma fibrinogen was elevated when compared with group 1 (median difference 0.6 g/L; p = 0.0001), with a trend toward high von Willebrand factor levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Objective measurement of changes in regional wall motion characteristics following coronary artery bypass grafting using tomographic radionuclide ventriculography

Difficulties arise when using non-invasive methods to measure changes in regional left ventricular function. With the increasing recognition of the entity of hibernating myocardium, and the known asymmetric effects of coronary artery disease, this is an important problem, as it prevents detailed investigation of the effects of revascularization upon ventricular function. We investigated the use of tomographic radionuclide ventriculography in assessing such changes. Twenty consecutive patients (18 males, 2 females, mean age 60 years), undergoing elective coronary artery bypass surgery, were identified and imaged prior to and after surgery. The mean global left ventricular ejection fraction was 42 and 45% pre- and post-surgery, respectively. Following revascularization, it was improved in 9 patients, unchanged in 3 and deteriorated in 8. By comparison with pooled normal data from 25 subjects, 10 patients were noted to have overall resting phase values within normal limits. After surgery, an improvement was seen in 5 patients, no significant change in 11 and a deterioration in 4. With respect to regional ejection fraction, 24 of 80 segments improved, 25 remained unchanged and 31 deteriorated. For regional phase analysis, 26 improved, 45 remained unchanged and 9 deteriorated. confirmed that important regional changes in left ventricular function occur following revascularization, even without a change in global ejection fraction.

Is diastolic dysfunction associated with thrombogenesis? A study of circulating markers of a prothrombotic state in patients with coronary artery disease

Clinical data on the contributory role of heart failure to thromboembolic risk does not differentiate between systolic and diastolic left ventricular dysfunction. We therefore conducted a population-controlled cross-sectional study to determine levels of plasma fibrinogen (associated with thromboembolism), fibrin D-dimer (a marker of fibrin turnover) and von Willebrand factor (a marker of endothelial dysfunction) in patients with ischaemic heart disease (a common cause of diastolic dysfunction) in whom left ventricular diastolic function was defined by echocardiography. We studied 106 patients: those with normal left ventricular function (n = 42, Group 1); those with left ventricular dysfunction but without aneurysms (n = 34, Group 2); and those with left ventricular aneurysm formation (n = 30, Group 3). Each of these groups was subdivided into those with (a) and without (b) diastolic dysfunction. Diastolic dysfunction was present in over 60% of patients, irrespective of left ventricular systolic impairment. There were no significant differences in median levels of plasma fibrinogen, fibrin D-dimer or von Willebrand factor in each group of patients with ischaemic heart disease, whether or not left ventricular diastolic dysfunction was present (Mann-Whitney test; P = N.S.). Systolic (rather than diastolic) dysfunction was the main correlate of these (analysis of variance, general linear model--ANOVA-GLM--P < 0.05) and the greatest abnormalities of fibrinogen, endothelial dysfunction and intravascular fibrin turnover were seen in patients with left ventricular aneurysms whether or not diastolic dysfunction was present. This study demonstrates that there is no evidence of a significant additional contribution to thrombotic risk (as assessed by plasma fibrinogen, von Willebrand factor and fibrin D-dimer) for patients with left ventricular diastolic dysfunction. A relationship is noted between some prothrombotic factors and Doppler indices of flow, which suggests a possible association between cardiac haemodynamics and thrombogenesis.

Do radionuclide and echocardiographic techniques give a universal cut off value for left ventricular ejection fraction that can be used to select patients for treatment with ACE inhibitors after myocardial infarction?

OBJECTIVE

To determine whether echocardiography and radionuclide angiography give comparable results when the left ventricular ejection fraction is measured early after myocardial infarction and thus whether, irrespective of the method used, a single value for the ejection fraction could be used as a guide for starting treatment with an angiotensin converting enzyme inhibitor.

DESIGN

Prospective comparison of measurement of left ventricular ejection fraction by echocardiography and radionuclide angiography.

SETTING

Coronary care units of two university teaching hospitals in Glasgow.

PATIENTS

99 patients studied within 36 hours of acute myocardial infarction.

OUTCOME MEASURES

Left ventricular ejection fraction assessed by echocardiography and radionuclide angiography.

RESULTS

70 (77%) of the 99 patients had ejection fraction measured by both echocardiographic and radionuclide techniques, 30 in centre 1 and 40 in centre 2. In centre 1 the mean difference (SD) in ejection fraction (radionuclide angiography--echocardiography) was -8 (10%); 95% CI -12 to -4%. In centre 2 the mean difference was -14 (11%); 95% CI -17 to -11%. If patients had been treated with an ACE inhibitor on the basis of a radionuclide ejection fraction of < 40% then 93% in centre 1 (28 of 30) and 98% in centre 2 (39 of 40) would have been treated. This compares with 63% (19 of 30) and 50% (20 of 40), respectively if echocardiography had been used as a guide.

CONCLUSION

Measurement of ejection fraction is highly dependent on the method used and it is therefore impossible to quote a universally applicable figure for left ventricular ejection fraction below which an ACE inhibitor should be used after myocardial infarction.

A cross-over study comparing the efficacy of a combination of atenolol and nifedipine at different doses in angina pectoris

Although the combined administration of atenolol and nifedipine has been shown to be effective in the treatment of angina pectoris the optimum dosage level of the combination has not yet been established. A double-blind, randomly assigned three period cross-over study was carried out therefore to investigate the effects of different daily doses of a fixed combination of 50 mg atenolol and 20 mg sustained-release nifedipine per capsule. Twenty-one patients with stable angina pectoris were randomized, after a 2-week run-in period, to receive treatment for 4 weeks with either 1 capsule twice daily (A), 2 capsules in the morning and 1 in the evening (B), or 2 capsules twice daily (C). A treadmill exercise tolerance test was performed together with a clinical evaluation after the run-in and each of the three treatment periods. Analysis of the results from the 19 patients who completed the study revealed there were no significant differences between the three treatment periods with respect to the general exercise test parameters, number of anginal attacks per week or nitrate consumption. Few side-effects were reported and were only mild in nature. On these findings, therefore, there would appear to be little justification for increasing the dose of the combination above the equivalent of treatment A.

Factors influencing coronary artery bypass graft patency

Coronary artery bypass surgery is one of the most frequently performed and successful operations in improving quality of life for patients with intractible angina. Unfortunately, there is accumulating evidence that angina will eventually return and consequently an increasing amount of repeat surgery is being undertaken. Subsequent operations have a reduced chance of benefit and many patients are only in early middle age at the time of initial surgery. It is obviously of paramount importance, therefore, to try and maintain graft patency for as long as possible. Various factors such as avoidance of certain surgical techniques, use of the internal mammary artery whenever possible, continued use of aspirin and attention to major risk factors are known to significantly influence graft patency. This review examines these factors in detail and provides practical advice on how to optimize long-term patency.

Have we identified the factors affecting prognosis following coronary artery bypass surgery?

Although coronary artery bypass graft (CABG) surgery has been an established therapeutic alternative for more than 20 years in the palliation of symptoms of ischaemic heart disease, the associated risk factors for subsequent mortality and morbidity in these patients remain unclear. This is pertinent, as CABG surgery does not affect the underlying pathological process and different factors affect the early and late postoperative outcomes. As one objective of CABG surgery is to provide symptomatic relief of angina, it is desirable to identify (and perhaps modify) the factors affecting prognosis and outcome. An awareness of these factors will allow better patient selection and the development of better screening and therapeutic interventions.

Images in cardiology. ECG changes of severe hyperkalaemia

Images

Polar map or novel three-dimensional display technique for the improved detection of inferior wall myocardial infarction using tomographic radionuclide ventriculography

Tomographic radionuclide ventriculography has the potential to be a significant improvement over conventional planar imaging. Although tomographic imaging can now be performed with relative ease, it is little used. This is most probably due to a perceived imbalance between potential clinical benefit and the extra complications of imaging. We investigated this matter by examining a series of 30 patients with isolated inferior or anterior myocardial infarction, identified by cardiac catheterization. Using either radionuclide imaging method, a significant wall motion abnormality was defined as matching (and appropriately located) phase and amplitude values outwith of two standard deviations from control values. These values were obtained from a series of 25 controls and represent construction values used to create a conventional polar map display. Overall detection rates for anterior myocardial infarction were 93 and 100% for planar and tomographic imaging, respectively (ns). For inferior myocardial infarction the rates were 7 and 93%, respectively (p < 0.001). Identical results were found using a novel three-dimensional method of displaying wall motion abnormalities. Tomography is therefore superior to planar imaging for the detection of inferior myocardial infarction but similar to planar imaging for the detection of anterior myocardial infarction.

Assessment of left ventricular regional wall motion with blood pool tomography: comparison of 11CO PET with 99Tcm SPECT

Left ventricular contraction is routinely assessed by radionuclide ventriculography. Although a planar image is conventionally used, tomography has been to improve the detection of wall motion abnormalities. A blood pool image is often used in positron emission tomography on which to superimpose metabolic tracers. Can this image also be used to assess left ventricular contraction? Nine healthy controls, mean (S.D.) age 55 (5) years, and 12 patients, mean (S.D.) age 61 (8) years, with normal, proven or suspected left ventricular damage underwent blood pool tomography with 11CO positron emission tomography (PET) and 99Tcm single photon emission computed tomography (SPECT). A normal value of ejection fraction and range of phase were defined. The normal left ventricular ejection fraction was > or = 37% for PET and > or = 40% for SPECT. The ejection fractions obtained by the two methods in the patient group were positively correlated (r = 0.89, P < 0.001). Abnormalities of left ventricular contraction were detected in nine patients by PET and 10 patients by SPECT imaging. The discrepancy was in a patient with a previous inferior myocardial infarction. Blood pool imaging with 11CO PET can be used to assess left ventricular ejection fraction and regional wall motion.

Improved detection of abnormal left ventricular wall motion using tomographic radionuclide ventriculography compared with planar radionuclide and single plane contrast ventriculography

Tomographic radionuclide ventriculography is a technique which could have major advantages over conventional planar imaging, such as better assessment of ventricular wall motion abnormalities. This possibility was therefore investigated in 100 consecutive patients undergoing routine cardiac catheterization. Following angiography, planar blood pool images were conventionally acquired and tomographic imaging performed using the Aberdeen Section Scanner. All derived wall motion data were subsequently analysed in an objective and blinded manner. The mean age was 56 (range 33-71) and 79% were male. 67 patients had experienced prior myocardial infarction, 27 were categorized as having significant and six insignificant coronary artery disease. The detection rates for patients with prior myocardial infarction were 95% for angiography, 57% for planar imaging and 90% for tomography. Even taking patients with only prior anterior myocardial infarction, the detection rates were 94%, 63% and 91% respectively. For those residual patients with significant coronary artery disease, the rates were 7%, 0% and 59% respectively. Overall for the detection of patients with significant coronary artery disease, the sensitivity was 70%, 40% and 81% respectively. Patients with insignificant coronary artery disease did not demonstrate any abnormalities using any method. These results demonstrate that tomography and angiography have similar detection rates in the presence of significant coronary artery disease and both are superior to planar imaging.

Management of paroxysmal atrial fibrillation

Paroxysmal atrial fibrillation is a common, poorly understood and difficult-to-treat arrhythmia. Although it tends to be treated in a similar fashion to chronic atrial fibrillation, its pathophysiology is different, and drugs commonly used for chronic atrial fibrillation may have only limited value in treating paroxysmal atrial fibrillation. A broad range of presenting clinical symptoms may be associated with this arrhythmia, and even in the asymptomatic patient, there may be a risk of serious thromboembolic events. In symptomatic patients, effective control of paroxysms with antiarrhythmic therapy can often be difficult, and the role of anticoagulation remains controversial. This review attempts to clarify these issues, by surveying the range of therapies available.

Adrenaline in allergic emergencies

Images

Association of patient delay with symptoms, cardiac enzymes, and outcome in acute myocardial infarction

The delay between the onset of symptoms and the call for help is the longest single component of the time taken for patients with acute myocardial infarction to come under coronary care and receive thrombolytic therapy. In order to investigate factors influencing patient delay, visual analogue scores for pain, shortness of breath, and anxiety were obtained retrospectively from 250 patients with acute myocardial infarction, for the time of onset of symptoms, and for the time of the call for help. The predominant symptom was chest pain, followed by anxiety and breathlessness. Although all symptoms increased in severity after their onset, the initiation of a call was largely unexplained in terms of worsening symptoms. Patient delay had a skewed distribution with modal, median and mean values of up to 1 h, 1.5 h, and 11 h respectively. Patient delay was negatively correlated with the pain score at the time of calling, but most of the variance of patient delay could not be explained in terms of symptom scores. However, patient delay was independently and negatively related to maximum serum aspartate aminotransferase. During acute myocardial infarction, patients with higher cardiac enzyme levels experience more pain and delay less. This tendency for patients with more severe infarction and a greater risk of death to call for help sooner is an added reason for administering thrombolytic treatment at the first opportunity: those patients who call early have most to gain from prompt therapy.

Six year follow up of a consecutive series of patients presenting to the coronary care unit with acute chest pain: prognostic importance of the electrocardiogram

In a retrospective 6 year follow up data were obtained for 536 of 566 (95%) consecutive patients admitted to a coronary care unit with acute chest pain. Their diagnoses were acute myocardial infarction in 290 (54%), myocardial ischaemia in 164 (31%), pericarditis in 16 (3%), and non-cardiac in 66 (12%). Six year mortality was 36%, 24%, 0%, and 16% respectively. In patients with acute myocardial infarction a higher mortality rate during follow up was associated with a higher than average age, a higher than average creatine kinase, previous myocardial infarction, Q wave infarction, and the presence of reciprocal changes. The presence of reciprocal changes was associated with higher than average concentration of serum creatine kinase, indicating more extensive infarction. Infarction complicated by ventricular fibrillation or left bundle branch block was associated with a higher death rate. The electrocardiogram recorded at the time of acute myocardial infarction contains much useful prognostic information.

Time of occurrence, duration, and ventricular rate of paroxysmal atrial fibrillation: the effect of digoxin

One hundred and thirty nine episodes of atrial fibrillation were identified from Holter recordings in 72 patients with paroxysmal atrial fibrillation. Paroxysms occurred more often by day than by night, suggesting that attacks are more closely associated with sympathetic than with vagal activity. In 41 patients who were not taking digoxin there were 79 episodes, and in 31 patients who were taking digoxin there were 60 episodes. Significantly more of the episodes that lasted for 30 minutes or more occurred in patients taking digoxin (13/17); the relative risk of a prolonged paroxysm associated with taking digoxin was 4.3 (95% confidence intervals 1.6-11.9). The mean (SD) ventricular rate at the onset of the paroxysms was not significantly different in those taking digoxin (140 (25) beats/min) and in those who were not (134 (22) beats/min). In paroxysmal atrial fibrillation, pretreatment with digoxin does not seem to reduce the frequency of paroxysms, or the ventricular rate when paroxysms occur, but it is associated with longer attacks.

Low-field cine magnetic resonance imaging in aortic valve disease

Cine magnetic resonance imaging (MRI) holds considerable promise as a means of detecting abnormal blood flow patterns with the heart and great vessels. To date, the majority of techniques employed have required moderate to high field strengths. We describe a novel, low-field-strength approach that is technically undemanding and faster than conventional methods, which we have applied to the detection of aortic valve disease. A series of 26 patients with aortic stenosis or aortic regurgitation was compared with 21 normal subjects. All 20 patients with aortic stenosis and 15 of 16 patients with aortic regurgitation were identified. There were four false positives in the aortic stenosis group; all these patients had significant aortic regurgitation. There were no false positives in the aortic regurgitation group. Low-field cine MRI is a practical and useful technique for the detection of aortic valve disease.

Stroke distance in acute myocardial infarction: a simple measurement of left ventricular function

Stroke distance was measured by means of doppler ultrasound in 100 consecutive patients with acute myocardial infarction. Mean stroke distance on days 1-5 after infarction was 72% of the predicted normal value for age and rose to 77% of normal by days 6-10. Stroke distance was lower after anterior (65%) than inferior infarction (75%), and was negatively correlated with peak serum aspartate aminotransferase (r = 0.47, p less than 0.001). Of 16 patients whose stroke distance on days 1-5 was below 50% of normal for age, 4 died, all within the first week. Of 84 patients whose stroke distance was 50% of normal or higher, only 1 died (at 13 days). The simple bedside measurement of stroke distance offers a practical method of monitoring left ventricular function in acute myocardial infarction: the measurement may have prognostic value.

The effects of treatment with felodipine as a single agent in coronary artery disease

In an earlier study one dose of the vasodilator felodipine improved haemodynamic function in patients with angina without having a negative inotropic effect. The haemodynamic response of sustained treatment with felodipine as a single agent in stable angina was investigated in a double blind crossover study of 25 patients. The dosage of felodipine was increased from 5 mg twice daily to 10 mg twice daily after two weeks. Twenty one patients completed the study, two were withdrawn because of acute myocardial infarction, and a further two because of symptoms of vasodilatation. Felodipine reduced both supine and erect blood pressure and increased the resting heart rate. Median exercise time was increased by 10% at two weeks and 7% at four weeks. There was a sustained reduction in the number of angina attacks and use of sublingual nitrate on active treatment. Felodipine has antianginal effects but these are limited and seem less than those of other related compounds. This finding is unexpected and possibly related to increased heart rate.