Showing papers in "Heart in 1999"

Left atrial appendage: structure, function, and role in thromboembolism

Abstract: The left atrial appendage (LAA) is derived from the left wall of the primary atrium, which forms during the fourth week of embryonic development. It has developmental, ultrastructural, and physiological characteristics distinct from the left atrium proper. The LAA lies within the confines of the pericardium in close relation to the free wall of the left ventricle and thus its emptying and filling may be significantly affected by left ventricular function. The physiological properties and anatomical relations of the LAA render it ideally suited to function as a decompression chamber during left ventricular systole and during other periods when left atrial pressure is high. These properties include the position of the LAA high in the body of the left atrium; the increased distensibility of the LAA compared with the left atrium proper; the high concentration of atrial natriuretic factor (ANF) granules contained within the LAA; and the neuronal configuration of the LAA. Thrombus has a predilection to form in the LAA in patients with atrial fibrillation, mitral valve disease, and other conditions. The pathogenesis has not been fully elucidated; however, relative stasis which occurs in the appendage owing to its shape and the trabeculations within it is thought to play a major role. Obliteration or amputation of the LAA may help to reduce the risk of thromboembolism, but this may result in undesirable physiological sequelae such as reduced atrial compliance and a reduced capacity for ANF secretion in response to pressure and volume overload.

Aortic root dilatation in young men with normally functioning bicuspid aortic valves

Abstract: OBJECTIVE—To evaluate the dimensions of the aortic root in a selected population of young males with isolated normally functioning bicuspid aortic valve. DESIGN AND SETTING—Echocardiographic and Doppler evaluation of conscripts with bicuspid aortic valve at the time of military pre-enrolment screening in two military hospitals. SUBJECTS AND METHODS—66 consecutive young men with a normally functioning bicuspid aortic valve were studied to assess aortic size at four aortic levels: annulus, sinuses of Valsalva, supra-aortic ridge, and proximal ascending aorta; 70 consecutive normal young subjects, matched for age and body surface area, were used as controls. RESULTS—In men with a bicuspid aortic valve, the diameter of the aortic root was significantly larger than in controls at the sinuses (3.16 (0.37) v 2.87 (0.31) cm, p < 0.001), at the supra-aortic ridge (2.64 (0.46) v 2.47 (0.28) cm, p = 0.01), and at the level of the proximal ascending aorta (3.12 (0.48) v 2.69 (0.28) cm, p < 0.001). The prevalence of aortic root dilatation was 7.5% at the annulus (5/66), 19.6% at the sinuses (13/66), 15% at the supra-aortic ridge (10/66), and 43.9% at the ascending aorta (29/66); 32 subjects (48%) had aortic root dimensions comparable with controls, while 34 (52%) had definitely abnormal aortic root dimensions. CONCLUSIONS—Aortic root enlargement in people with a bicuspid aortic valve occurs independently of haemodynamic abnormalities, age, and body size. However, there appear to be different subgroups of young adults with bicuspid aortic valves, one of which is characterised by aortic dilatation, possibly caused by a congenital abnormality of the aortic wall. Keywords: bicuspid aortic valve; aortic root dilatation

Plaque erosion is a major substrate for coronary thrombosis in acute myocardial infarction

Abstract: Objective—To evaluate the prevalence of plaque erosion as a substrate for coronary thrombosis. Design—Pathological study in patients with acute myocardial infarction not treated with thrombolysis or coronary interventional procedures. Patients—298 consecutive patients (189 men, mean (SD) age 66 (11) years; 109 women, 74 (8) years) dying in hospital between 1984 and 1996 from acute myocardial infarction, diagnosed by ECG changes and rise in cardiac enzymes. Main outcome measures—Histopathological determination of plaque erosion as substrate for acute thrombosis; location and histological type of coronary thrombosis; acute and healed myocardial infarcts; ventricular rupture. Results—Acute coronary thrombi were found in 291 hearts (98%); in 74 cases (25%; 40/107 women (37.4%) and 34/184 men (18.5%); p = 0.0004), the plaque substrate for thrombosis was erosion. Healed infarcts were found in 37.5% of men v 22% of women (p = 0.01). Heart rupture was more common in women than in men (22% v 10.5%, p = 0.01). The distribution of infarcts, thrombus location, heart rupture, and healed infarcts was similar in cases of plaque rupture and plaque erosion. Conclusions—Plaque erosion is an important substrate for coronary thrombosis in patients dying of acute myocardial infarction. Its prevalence is significantly higher in women than in men. (Heart 1999;82:269‐272)

Mechanisms of progression in native coronary artery disease: role of healed plaque disruption

Abstract: OBJECTIVE To determine the role of healed plaque disruption in the generation of chronic high grade coronary stenosis. METHODS Coronary arteries obtained at necropsy were perfuse fixed with formal saline for 24 hours at 100 mg Hg. The percentage lumen diameter stenosis was measured in each 3 mm segment containing a plaque, using the lumen size at the nearest histologically normal segment as the reference point. Each segment was prepared for histological examination and stained with Sirius red and immunohistochemistry for smooth muscle actin. Healed disruption was considered to be present when under polarised light there was a break in the yellow–white dense collagen of the cap filled in by more loosely arranged green collagen. Increased smooth muscle density in the green staining areas was required. Each section was read independently by two observers; any segment with discordant views was considered negative. MATERIAL 31 men aged 51–69 dying suddenly of ischaemic heart disease. 39 coronary arteries were studied containing 256 separate plaques, after excluding coronary arteries with old total occlusions, an acute culprit thrombotic lesion, diffuse disease without normal arterial segments, and arteries related to old myocardial scars. RESULTS 16 of 99 plaques causing 2 test (p CONCLUSIONS Subclinical episodes of plaque disruption followed by healing are a stimulus to plaque growth that occurs suddenly and is a major factor in causing chronic high grade coronary stenosis. This mechanism would explain the phasic rather than linear progression of coronary disease observed in angiograms carried out annually in patients with chronic ischaemic heart disease.

High resolution in vivo intra-arterial imaging with optical coherence tomography

Abstract: Background—Optical coherence tomography (OCT) is a new method of catheter based micron scale imaging. OCT is analogous to ultrasound, measuring the intensity of backreflected infrared light rather than sound waves. Objective—To demonstrate the ability of OCT to perform high resolution imaging of arterial tissue in vivo. Methods—OCT imaging of the abdominal aorta of New Zealand white rabbits was performed using a 2.9 F OCT imaging catheter. Using an ultrashort pulse laser as a light source for imaging, an axial resolution of 10 µm was achieved. Results—Imaging was performed at 4 frames/second and data were saved in either super VHS or digital format. Saline injections were required during imaging because of the signal attenuation caused by blood. Microstructure was sharply defined within the arterial wall and correlated with histology. Some motion artefacts were noted at 4 frames/second. Conclusions—In vivo imaging of the rabbit aorta was demonstrated at a source resolution of 10 µm, but required the displacement of blood with saline. The high resolution of OCT allows imaging to be performed near the resolution of histopathology,oVering the potential to have an impact both on the identification of high risk plaques and the guidance of interventional procedures. (Heart 1999;82:128‐133)

To operate or not on elderly patients with aortic stenosis: the decision and its consequences

Abstract: Objective—To evaluate the application of guidelines in the decision making process leading to medical or surgical treatment for aortic stenosis in elderly patients. Design—Cohort analysis based on a prospective inclusive registry. Setting—205 consecutive patients (> 70 years) with clinically relevant isolated aortic stenosis and without serious comorbidity, seen for the first time in the Doppler-echocardiographic laboratories of three university hospitals in the Netherlands. Results—The initial choice was surgery in 94 patients and medical treatment in 111. Only 59% of the patients who should have had valve replacement according to the practice guidelines were actually oVered surgical treatment. These were mainly symptomatic patients under 80 years of age with a high gradient. Operative mortality (30 days) was only 2%. The three year survival was 80% in the surgical group (17 deaths among 94 patients) and 49% in the medical group (43/111). Multivariate analysis showed that only patients with a high baseline risk, mainly determined by impaired left ventricular function, had a significantly better three year survival with surgical treatment than with medical treatment. Conclusions—In daily practice, elderly patients with clinically relevant symptomatic aortic stenosis are often denied surgical treatment. This study indicates that a surgical approach, especially where there is impaired systolic left ventricular function, is associated with better survival. (Heart 1999;82:143‐148)

Contribution of modern cardiovascular treatment and risk factor changes to the decline in coronary heart disease mortality in Scotland between 1975 and 1994

Abstract: Objective—To estimate the fall in coronary heart disease (CHD) mortality in Scotland attributable to medical and surgical treatments, and risk factor changes, between 1975 and 1994. Design—A cohort model combining eVectiveness data from meta-analyses with information on treatment uptake in all patient categories in Scotland. Setting and patients—The whole Scottish population of 5.1 million, including all patients with recognised CHD. Interventions—All cardiological, medical, and surgical treatments, and all risk factor changes between 1975 and 1994. Data were obtained from epidemiological surveys, routine National Health Service sources, and local audits. Main outcome measures—Deaths from CHD in 1975 and 1994. Results—There were 15 234 deaths from CHD in 1994, 6205 fewer deaths than expected if there had been no decline from 1975 mortality rates. In 1994, the total number of deaths prevented or postponed by all treatments and risk factor reductions was estimated at 6747 (minimum 4790, maximum 10 695). Forty per cent of this benefit was attributed to treatments (initial treatments for acute myocardial infarction 10%, treatments for hypertension 9%, for secondary prevention 8%, for heart failure 8%, aspirin for angina 2%, coronary artery bypass grafting surgery 2%, and angioplasty 0.1%). Fifty one per cent of the reduction in deaths was attributed to measurable risk factor reductions (smoking 36%, cholesterol 6%, secular fall in blood pressure 6%, and changes in deprivation 3%). Other, unquantified factors apparently accounted for the remaining 9%. These proportions remained relatively consistent across a wide range of assumptions and estimates in a sensitivity analysis. Conclusions—Medical treatments and risk factor changes apparently prevented or postponed about 6750 coronary deaths in Scotland in 1994. Modest gains from individual treatments produced a large cumulative survival benefit. Reductions in major risk factors explained about half the fall in coronary mortality, emphasising the importance and future potential of prevention strategies. (Heart 1999;81:380‐386)

Transcatheter closure of atrial septal defect and interatrial communications with a new self expanding nitinol double disc device (Amplatzer septal occluder): multicentre UK experience

Abstract: OBJECTIVE To review the safety and efficacy of the Amplatzer septal occluder for transcatheter closure of interatrial communications (atrial septal defects (ASD), fenestrated Fontan (FF), patent foramen ovale (PFO)). DESIGN Prospective study following a common protocol for patient selection and technique of deployment in all participating centres. SETTING Multicentre study representing total United Kingdom experience. PATIENTS First 100 consecutive patients in whom an Amplatzer septal occluder was used to close a clinically significant ASD or interatrial communication. INTERVENTIONS All procedures performed under general anaesthesia with transoesophageal echocardiographic guidance. Interatrial communications were assessed by transoesophageal echocardiography with reference to size, position in the interatrial septum, proximity to surrounding structures, and adequacy of septal rim. Stretched diameter of the interatrial communications was determined by balloon sizing. Device selection was based on and matched to the stretched diameter of the communication. MAIN OUTCOME MEASURES Success defined as deployment of device in a stable position to occlude the interatrial communication without inducing functional abnormality or anatomical obstruction. Occlusion status determined by transoesophageal echocardiography during procedure and by transthoracic echocardiography on follow up. Clinical status and occlusion rates assessed at 24 hours, one month, and three months. RESULTS 101 procedures were performed in 100 patients (86 ASD, 7 FF, 7 PFO), age 1.7 to 64.3 years (mean (SD), 13.3 (13.9)), weight 9.2 to 100.0 kg (mean 32.5 (23.5)). Procedure time ranged from 30 to 180 minutes (mean 92.4 (29.0)) and fluoroscopy time from 6.0 to 49.0 minutes (mean 16.1 (8.0)). There were seven failures, all occurring in patients with ASD, and one embolisation requiring surgical removal. Immediate total occlusion rate was 20.4%, rising to 84.9% after 24 hours. Total occlusion rates at the one and three month follow up were 92.5% and 98.9%, respectively. Complications were: transient ST elevation (1), transient atrioventricular block (1), presumed deep vein thrombosis (1), presumed transient ischaemic attack (1). CONCLUSIONS It appears feasible to close interatrial communications and atrial septal defects up to 26 mm stretched diameter safely with the Amplatzer septal occluder. Short term results confirm an early high occlusion rate with no major complications. Careful selection of cases based on the echocardiographic morphology of the ASD and accurate assessment of their stretched diameter is of utmost importance. Further experience with the larger devices and longer term results are required before a firm conclusion regarding its use can be made.

Why patients do not attend cardiac rehabilitation: role of intentions and illness beliefs

Abstract: Objective—Many patients fail to attend cardiac rehabilitation. Attempts to identify sociodemographic or clinical predictors of non-attendance have not been very successful; therfore, this study aimed to determine whether the illness beliefs held during hospitalisation by patients who had suVered acute myocardial infarction or who had undergone coronary artery bypass graft surgery could predict cardiac rehabilitation attendance. Subjects and methods—152 patients were prospectively studied of whom 41% had attended cardiac rehabilitation at six months. Results—In addition to being older, less aware of their cholesterol values, and less likely to be employed, non-attenders were less likely to believe their condition was controllable and that their lifestyle may have contributed to their illness. Conclusion—It should now be determined whether interventions aimed at optimising certain perceptions could promote cardiac rehabilitation uptake among those patients who could benefit the most. (Heart 1999;82:234‐236)

Prospective randomised comparison between thrombolysis, rescue PTCA, and primary PTCA in patients with extensive myocardial infarction admitted to a hospital without PTCA facilities: a safety and feasibility study

Abstract: OBJECTIVE—To assess the safety and feasibility of acute transport followed by rescue percutaneous transluminal coronary angioplasty (PTCA) or primary PTCA in patients with acute myocardial infarction initially admitted to a hospital without PTCA facilities. DESIGN—In a multicentre randomised open trial, three regimens of treatment of acute large myocardial infarction were compared for patients admitted to hospitals without angioplasty facilities: thrombolytic treatment with alteplase (75 patients), alteplase followed by transfer to the PTCA centre and (if indicated) rescue PTCA (74 patients), or transfer for primary PTCA (75 patients). RESULTS—Between 1995 and 1997 224 patients were included. Baseline characteristics were distributed evenly. Transport to the PTCA centre was without severe complications in all patients. Mean (SD) delay from onset of symptoms to randomisation was 130 (75) minutes and from randomisation to angiography 90 (25) minutes. Death or recurrent infarction within 42 days occurred in 12 patients in the thrombolysis group, in 10 patients in the rescue PTCA group, and in six patients in the primary PTCA group. These differences were not significant. CONCLUSIONS—Acute transfer for rescue PTCA or primary PTCA in patients with extensive myocardial infarction is feasible and safe. Efficacy of rescue PTCA or primary PTCA in this setting will have to be tested in larger series before this approach can be implemented as "routine treatment" for patients with extensive myocardial infarction. Keywords: myocardial infarction; percutaneous transluminal coronary angioplasty; primary PTCA; rescue PTCA; reperfusion

Quality of life four years after acute myocardial infarction: short form 36 scores compared with a normal population

Abstract: Objectives—To assess the impact of myocardial infarction on quality of life in four year survivors compared to data from “community norms”, and to determine factors associated with a poor quality of life. Design—Cohort study based on the Nottingham heart attack register. Setting—Two district general hospitals serving a defined urban/rural population. Subjects—All patients admitted with acute myocardial infarction during 1992 and alive at a median of four years. Main outcome measures—Short form 36 (SF 36) domain and overall scores. Results—Of 900 patients with an acute myocardial infarction in 1992, there were 476 patients alive and capable of responding to a questionnaire in 1997. The response rate was 424 (89.1%). Compared to age and sex adjusted normative data, patients aged under 65 years exhibited impairment in all eight domains, the largest diVerences being in physical functioning (mean diVerence 20 points), role physical (mean diVerence 23 points), and general health (mean diVerence 19 points). In patients over 65 years mean domain scores were similar to community norms. Multiple regression analysis revealed that impaired quality of life was closely associated with inability to return to work through ill health, a need for coronary revascularisation, the use of anxiolytics, hypnotics or inhalers, the need for two or more angina drugs, a frequency of chest pain one or more times per week, and a Rose dyspnoea score of> 2. Conclusions—The SF 36 provides valuable additional information for the practising clinician. Compared to community norms the greatest impact on quality of life is seen in patients of working age. Impaired quality of life was reported by patients unfit for work, those with angina and dyspnoea, patients with coexistent lung disease, and those with anxiety and sleep disturbances. Improving quality of life after myocardial infarction remains a challenge for physicians. (Heart 1999;81:352‐358)

Is the Framingham risk function valid for northern European populations? A comparison of methods for estimating absolute coronary risk in high risk men

Abstract: Objective To examine the validity of estimates of coronary heart disease (CHD) risk by the Framingham risk function, for European populations. Design Comparison of CHD risk estimates for individuals derived from the Framingham, prospective cardiovascular Munster (PROCAM), Dundee, and British regional heart (BRHS) risk functions. Setting Sheffield Hypertension Clinic. Patients—206 consecutive hypertensive men aged 35–75 years without preexisting vascular disease. Results There was close agreement among the Framingham, PROCAM, and Dundee risk functions for average CHD risk. For individuals the best correlation was between Framingham and PROCAM, both of which use high density lipoprotein (HDL) cholesterol. When Framingham was used to target a CHD event rate > 3% per year, it identified men with mean CHD risk by PROCAM of 4.6% per year and all had CHD event risks > 1.5% per year. Men at lower risk by Framingham had a mean CHD risk by PROCAM of 1.5% per year, with 16% having a CHD event risk > 3.0% per year. BRHS risk function estimates of CHD risk were fourfold lower than those for the other three risk functions, but with moderate correlations, suggesting an important systematic error. Conclusion There is close agreement between the Framingham, PROCAM, and Dundee risk functions as regards average CHD risk, and moderate agreement for estimates within individuals. Taking PROCAM as the external standard, the Framingham function separates high and low CHD risk groups and is acceptably accurate for northern European populations, at least in men.

Long axis function in disease

Abstract: Although longitudinally directed fibres—situated mainly in the subepicardium and subendocardium regions of the left and right ventricular free walls and the papillary muscles—comprise only a small proportion of the total ventricular myocardial mass, they play a major role in the maintenance of normal ejection fraction and in determining atrioventricular interactions.1 Not surprisingly, therefore, loss of longitudinal fibre function leads to characteristic disturbances. Longitudinal function is always reduced when ventricular cavity size is increased, in addition ejection fraction is reduced and may be absent.2 3 This relation is consistent enough for long axis amplitude, or its equivalent, the amplitude of atrioventricular ring motion, to be used as an index of ejection fraction.4It applies not only to the left ventricle, where it can be shown to relate to prognosis but also to the right, where it provides a simple method of assessing right ventricular function.5 When overall long axis amplitude is low, peak shortening and lengthening rates are reduced. In restrictive left ventricular disease, long axis amplitude is low even when cavity size is normal at end diastole, although the effects of this reduction are apparent in a reduced amplitude of wall thickening and thus of shortening fraction.6 After mitral valve replacement, long axis amplitude is strikingly reduced; this does not occur with mitral valve repair or mild mitral stenosis,7 nor is it a consistent effect of cardiopulmonary bypass done for other reasons, and so is likely to be the result of loss of papillary muscle function. Although shortening fraction is frequently normal in such patients, normal wall thickening is associated with an exaggerated amplitude of epicardial motion, possibly to compensate for loss of the component owing to long axis shortening. Regional reduction in the extent and velocity of long axis shortening is common after …

Long term outcome after out-of-hospital cardiac arrest with physician staffed emergency medical services: the Utstein style applied to a midsized urban/suburban area.

Abstract: OBJECTIVE—To test the effect of a physician staffed advanced cardiac life support (ALS) system on patient outcome following out-of-hospital cardiac arrest. DESIGN—Observational study. SETTING—Two tier basic life support (BLS) and physician staffed ALS services in the midsized urban/suburban area of Heidelberg, Germany. PATIENTS—All patients suffering out-of-hospital cardiac arrest of cardiac aetiology between January 1992 and December 1994 and who were covered by ALS services. INTERVENTIONS—Physician staffed ALS services. MAIN OUTCOME MEASURES—Return of spontaneous circulation, hospital discharge, and one year survival, according to the Utstein style. RESULTS—Of 330 000 inhabitants, 755 suffered from cardiac arrest covered by the Heidelberg ALS services. In 512 patients, cardiopulmonary resuscitation had been initiated. Of 338 patients with cardiac aetiology, return of spontaneous circulation was achieved in 164 patients (49%), 48 (14%) were discharged alive, and 40 (12%) were alive one year later; most of these patients showed good neurological outcome. Thus, 4.85 patients with cardiac aetiology were saved by the ALS services and discharged alive per 100 000 inhabitants a year. Ventricular fibrillation or tachycardia was detected in 106 patients (31%), other cardiac rhythms in 40 (12%), and asystole in 192 (57%). Hospital discharge rates (and one year survival) in these subgroups were 34.0% (29.2%), 12.5% (7.5%), and 3.6% (3.1%), respectively. Discharge rates increased if cardiac arrest was witnessed (bystander, 20.0%; BLS/ALS personnel, 21.4%; non-witnessed arrest, 3.3%; p 8 minutes, 8.1%; p < 0.001). In 69 patients with bystander witnessed cardiac arrest with ventricular fibrillation, the discharge rate was 37.7%; 21 patients were alive after one year. CONCLUSIONS—A two tier BLS and physician staffed ALS system is associated with good long term outcome of patients suffering from out-of-hospital cardiac arrest of cardiac aetiology in a midsized urban/suburban area. Further studies, however, are required to assess whether having a physician in the ALS unit is an independent determinant for improved long term outcome. Keywords: out-of-hospital cardiac arrest; emergency medical services; long term outcome; Utstein style

Spectrum of congenital heart defects and extracardiac malformations associated with chromosomal abnormalities: results of a seven year necropsy study

Abstract: OBJECTIVE—To analyse the spectrum of congenital heart malformations, the frequency of extracardiac malformations, and the proportion of chromosome aberrations among fetuses sent for necropsy. MATERIAL—Necropsies were performed on 815 fetuses—448 induced abortions (55%), 220 spontaneous abortions (27%), and 147 stillbirths (18%)—during a seven year period (1991-97) in the department of pathology of the Charite Medical Centre in Berlin. A congenital heart defect was identified in 129 cases (16%). For all 129 fetuses, karyotyping and an ultrasound examination had been performed. RESULTS—Congenital heart defects were present in 22% of induced abortions (99 cases), 9% of spontaneous abortions (20 cases), and 7% of stillbirths (10 cases). The heart malformations were classified into 13 categories. A fetus with more than one defect was included only in the category of the most serious defect. The malformations in order of frequency were: ventricular septal defect (VSD) (28%), atrioventricular septal defect (AVSD) (16%), hypoplastic left heart (HLH) (16%), double outlet right ventricle (DORV) (12%), coarctation of the aorta (CoA) (6%), transposition of the great arteries (TGA) (4%), aortic valve stenosis (AoVS) (4%), tetralogy of Fallot (TOF) (3%), truncus arteriosus communis (TAC) (3%), pulmonary valve stenosis/pulmonary valve atresia (PaVS/PaVA) (3%), tricuspid atresia (TA) (3%), single ventricle (SV) (1.5%), and atrial septal defect (ASD) (0.5%). The most common congenital heart defects were VSD, AVSD, HLH, and DORV, which made up 72% of all the cases. In 11 cases the heart defect was isolated (no other cardiovascular or extracardiac malformations present), 85 cases (66%) were associated with additional cardiac malformations, 85 cases (66%) were associated with extracardiac malformations, and chromosome anomalies were detected in 43 cases (33%). CONCLUSIONS—Fetal congenital heart malformations are common. These defects are often associated with other cardiovascular and extracardiac malformations, as well as with chromosome anomalies. Complex heart defects such as AVSD, HLH, and DORV are frequent in fetuses, as they often lead to spontaneous abortion or stillbirth or, after prenatal diagnosis, to deliberate termination of pregnancy. Keywords: congenital heart defects; extracardiac malformations; chromosomal abnormalities; necropsy examination

How often are angiotensin II and aldosterone concentrations raised during chronic ACE inhibitor treatment in cardiac failure

Abstract: OBJECTIVE—Angiotensin II (AII) and aldosterone are not always fully suppressed during chronic angiotensin converting enzyme (ACE) inhibitor treatment. In congestive heart failure (CHF) such failure of hormonal suppression is associated with increased mortality. This study examined how common AII and aldosterone increases are observed during routine clinical practice. PATIENTS AND METHODS—91 patients with symptomatic (mean New York Heart Association class 2.7) CHF (mean (SD) left ventricular ejection fraction 29.9 (8)%, range 9-46%) were studied 4-6 hours after ACE inhibitor dosing. A representative range of ACE inhibitors (enalapril, lisinopril, captopril, perindopril, and fosinopril) was examined. RESULTS—Supine measurements showed a wide range of AII (10.5 (25.5) pg/ml), aldosterone (130.8 (136) pg/ml), and serum ACE (12.1 (13.3) EU/l; excludes captopril data) concentrations on diuretics. AII concentrations > 10 pg/ml were seen in 15% of patients, and aldosterone concentrations > 144 pg/ml were seen in 38% of patients. AII concentrations were significantly correlated (p < 0.001) with ACE but not with aldosterone concentrations. Aldosterone concentrations were not significantly correlated with ACE concentrations. CONCLUSIONS—AII "reactivation" occurred in 15% and failure of aldosterone suppression in 38% of routine CHF patients taking ACE inhibitor treatment. AII "reactivation" was associated with both low and high levels of ACE activity, which suggests that multiple different mechanisms are at play. In patients with high plasma ACE concentrations, non-compliance should be considered along with inadequate dose titration. In patients with low plasma ACE and high AII concentrations, non-ACE mediated production of AII may be operative. Raised aldosterone concentrations appear to be more common than AII "reactivation". It is important to establish the cause of detectable or increased AII concentrations in a heart failure patient treated with an ACE inhibitor. The measurement of serum ACE may help to identify the likely cause as poor compliance or inadequate dose. Keywords: heart failure; hormone suppression; angiotensin II; aldosterone; angiotensin converting enzyme inhibitors; compliance

Pacemaker lead infection: echocardiographic features, management, and outcome

Abstract: Objective To compare transthoracic and transoesophageal echocardiography (TTE, TOE) in patients with permanent pacemaker lead infection and to evaluate the safety of medical extraction in cases of large vegetations. Methods TTE and TOE were performed in 23 patients with definite pacemaker lead infection. Seventeen patients without previous infection served as a TOE reference for non-infected leads. Results TTE was positive in seven cases (30%) whereas with TOE three different types of vegetations attached to the leads were visualised in 21 of the 23 cases (91%). Of the 20 patients with vegetations and lead culture, 17 (85%) had bacteriologically active infection. Left sided valvar endocarditis was diagnosed in two patients. In the control group, strands were visualised by TOE in five patients, and vegetations in none. Medical extraction of vegetations ⩾ 10 mm was performed in 12 patients and was successful in nine (75%) without clinical pulmonary embolism. After 31.2 (19.1) months of follow up (mean (SD)), all patients except one were cured of infection; three died from other causes. Conclusions Combined with bacteriological data, vegetations seen on TOE strongly suggest pacemaker lead infection. Normal TTE examinations do not exclude this diagnosis because of its poor sensitivity. Medical extraction of even large vegetations appeared to be safe.

Normal long axis function

Abstract: Ever since the time of Vesalius and Harvey,1 it has been recognised that the fall in cavity volume with left ventricular systole involves longitudinal as well as circumferential shortening, although the latter plays the dominant role. This asymmetry is reflected in myocardial structure—most of the left ventricular fibres are arranged circumferentially, particularly in the mid-wall and the base of the ventricle, however, with the progressive change in fibre angle across the wall, longitudinally directed fibres are found in the subendocardial and subepicardial free wall (fig 1) as well as in the papillary muscles.2 Figure 1 Diagram showing dissection in a normal left ventricular myocardium with the longitudinal fibres running between the apex and mitral ring and occupying the subendocardial and subepicardial layers. In view of the preponderance of circumferential fibres, it seems logical to deduce underlying myocardial function from the extent and velocity of their shortening3; however, the picture of the underlying function reached from observing changes in left ventricular minor axis is at first sight surprising. Normal dimensions fall by 25–40% during ejection, while the normally loaded sarcomere shortens by only 10–12%.4 Furthermore, this remarkable fall in minor axis is the result of thickening of the posterior wall to an extent much greater than would be expected from simultaneous inward movement of the epicardium.5 This apparent increase in myocardial mass that must underlie the observed extent of thickening can only be explained by concurrent shortening, and thus transverse thickening, of the longitudinally directed fibres. Without this longitudinal component, normal sarcomere shortening would lead to a shortening fraction of 12% and an ejection fraction of less than 30%. Thus, even normal changes in minor axis with ejection can be explained only on the basis of the combined action of the circumferential and longitudinal fibres.6 This …

Neuroendocrine prediction of left ventricular function and heart failure after acute myocardial infarction

Abstract: Objective—To determine the relations of plasma levels of brain natriuretic peptide (BNP), atrial natriuretic factor (ANF), N-terminal ANF (N-ANF), cyclic guanosine monophosphate (cGMP; the cardiac peptide second messenger), and plasma catecholamines to left ventricular function and to prognosis in patients admitted with acute myocardial infarction. Design—Plasma hormones and ventricular function (radionuclide ventriculography) were measured 1‐4 days after myocardial infarction in 220 patients admitted to a single coronary care unit. Radionuclide scanning was repeated 3‐5 months after infarction. Clinical events were recorded over a mean period of 14 months. Results—Both early and late left ventricular ejection fraction (LVEF) were most closely related to plasma BNP (r = ˛0.60, n = 220, p < 0.001; and r = ˛0.53, n = 192, p < 0.001, respectively), followed by ANF, N-ANF, cGMP, and the plasma catecholamines. Early plasma BNP concentrations less than twofold the upper limit of normal (20 pmol/l) had 100% negative predictive value for LVEF < 40% at 3‐5 months after infarction. In multivariate analysis incorporating all the neurohormonal factors, only BNP remained independently predictive of LVEF < 40% (p < 0.005). Survival analysis by median levels of candidate predictors identified BNP as the most powerful discriminator for death (p < 0.0001). No early deaths (within 4 months) occurred in patients with plasma BNP concentrations below the group median (27 pmol/l), and over follow up only three of 26 deaths occurred in this subgroup. Of all episodes of left ventricular failure, 85% occurred in patients with plasma BNP above the median (p < 0.001). In multivariate analyses, BNP alone gave additional predictive information beyond sex, age, clinical history, LVEF, and plasma noradrenaline for both subsequent onset of LVF and death. Conclusions—Plasma BNP measured within 1‐4 days of acute myocardial infarction is a powerful independent predictor of left ventricular function, heart failure, or death over the subsequent 14 months, and superior to ANF, N-ANF, cGMP, and plasma catecholamines. (Heart 1999;81:114‐120)

External cardioversion of atrial fibrillation: role of paddle position on technical efficacy and energy requirements

Abstract: AIM To define the effect of defibrillator paddle position on technical success and dc shock energy requirements of external cardioversion of atrial fibrillation. METHODS 301 patients (mean (SD) age 62 (11) years) with stable atrial fibrillation were randomly assigned to elective external cardioversion using anterolateral paddle position (ventricular apex–right infraclavicular area; group AL (151 patients)) or anteroposterior paddle position (sternal body–angle of the left scapula; group AP (150 patients)). A step up protocol was used, delivering a 3 J/kg body weight dc shock, then a 4 J/kg shock (maximum 360 J), and finally a second 4 J/kg shock using the alternative paddle location. RESULTS The two groups were comparable for the all clinical variables evaluated. The cumulative percentage of patients successfully converted to sinus rhythm was 58% in group AL and 67% in group AP with low energy dc shock (NS); this rose to 76% in group AL and to 87% in group AP with high energy dc shock (p = 0.013). Thirty seven patients in group AL and 19 in group AP experienced dc shock with the alternative paddle position; atrial fibrillation persisted in 10/37 in group AL and in 10/19 in group AP. Mean dc shock energy requirements were lower for group AP patients than for group AL patients, at 383 (235) v 451 (287) J, p = 0.025. Arrhythmia duration was the only factor that affected the technical success of external cardioversion (successful: 281 patients, 80 (109) days; unsuccessful: 20 patients, 193 (229) days; p 6 months: 29 of 37 (78%) v 252 of 264 (95%); p = 0.0001. CONCLUSIONS An anteroposterior defibrillator paddle position is superior to an anterolateral location with regard to technical success in external cardioversion of stable atrial fibrillation, and permits lower dc shock energy requirements. Arrhythmia duration is the only clinical variable that can limit the restoration of sinus rhythm.

Changes in cardiorespiratory fitness, psychological wellbeing, quality of life, and vocational status following a 12 month cardiac exercise rehabilitation programme.

Abstract: OBJECTIVE To examine and evaluate improvements in cardiorespiratory fitness, psychological wellbeing, quality of life, and vocational status in postmyocardial infarction patients during and after a comprehensive 12 month exercise rehabilitation programme. SUBJECTS The sample population comprised 124 patients with a clinical diagnosis of myocardial infarction (122 men and two women). INTERVENTIONS 62 patients were randomly allocated to a regular weekly aerobic training programme, three times a week for 12 months, and compared with 62 matched controls who did not receive any formal exercise training. A five year follow up questionnaire/interview was subsequently conducted on this population to determine selected vocational/lifestyle changes. RESULTS Significant improvements in cardiorespiratory fitness (p CONCLUSIONS Regularly supervised and prolonged aerobic exercise training improves cardiorespiratory fitness, psychological status, and quality of life. The trained population also had a reduction in morbidity following myocardial infarction, and significant improvement in vocational status over a five year follow up period.

Screening of ruptured plaques in patients with coronary artery disease by intravascular ultrasound

Abstract: AIM To visualise the characteristics of ruptured plaques by intravascular ultrasound (IVUS) and to correlate plaque characteristics with clinical symptoms to establish a quantitative index of plaque vulnerability. METHODS 144 consecutive patients with angina were examined using IVUS. Ruptured plaques, characterised by a plaque cavity and a tear on the thin fibrous cap, were identified in 31 patients (group A), of whom 23 (74%) presented with unstable angina. Plaque rupture was confirmed by injecting contrast medium filling the plaque cavity during IVUS examination. Of the patients without plaque rupture (group B, n = 108), only 19 (18%) had unstable angina. RESULTS No significant differences were found between groups A and B in relation to plaque and vessel area (p > 0.05). Mean (SD) per cent stenosis in group A was less than in group B, at 56.2 (16.5)% v 67.9 (13.4)%; p 2 ) was larger than the echolucent zone in group B (1.32 (0.79) mm 2 ) (p v 0.96 (0.94) mm; p CONCLUSIONS Plaques seem to be prone to rupture when the echolucent area is larger than 4.1 (3.2) mm 2 , when the echolucent area to plaque ratio is greater than 38.5 (17.1)%, and when the fibrous cap is thinner than 0.7 mm. IVUS can identify plaque rupture and vulnerable plaques. This may influence patient management and treatment.

Survival and complication free survival in Marfan's syndrome: implications of current guidelines

Abstract: OBJECTIVE To evaluate survival and complication free survival in patients with Marfan’s syndrome and to assess the possible influence of recently revised guidelines for prophylactic aortic root replacement in these patients. METHODS 130 patients who had been attending one institution over 14 years were evaluated. Kaplan–Meier analysis was performed in 125 patients who did not present with aortic root dissection as the first sign of Marfan’s syndrome, with the end points: death, aortic root dissection, and prophylactic aortic root replacement after diagnosis. In the patients developing aortic root dissection, current guidelines for prophylactic aortic root replacement were retrospectively applied to investigate the number of dissections that could theoretically have been prevented. The guidelines were: (1) aortic root diameter ⩾ 55 mm, (2) positive family history of aortic dissections and aortic root diameter ⩾ 50 mm, and (3) aortic root growth ⩾ 2 mm/year. Outcomes following emergency surgery (15 patients) and prophylactic surgery of the aortic root (30 patients) were compared. RESULTS Five and 10 year survival after diagnosis was 95% and 88%, and the five and 10 year complication free survival was 78% and 66%, respectively. Thirteen patients developed dissection, 30 underwent prophylactic repair, and 82 had an uncomplicated course. Eleven dissections could theoretically have been prevented by application of the current guidelines. Five year survival following emergency and prophylactic repair of the aortic root was 51%, and 97%, respectively. CONCLUSIONS Survival in the Marfan’s syndrome in the past 14 years seems satisfactory; with application of current guidelines, it has probably even improved. However, because of the high fatality rate in Marfan patients developing aortic root dissection, more extensive screening for Marfan’s syndrome and a search for additional risk factors are desirable.

Clinical outcomes of acute myocarditis in childhood

Abstract: OBJECTIVE To describe clinical outcomes of a paediatric population with histologically confirmed lymphocytic myocarditis. DESIGN A retrospective review between November 1984 and February 1998. SETTING A major paediatric tertiary care hospital. PATIENTS 36 patients with histologically confirmed lymphocytic myocarditis. MAIN OUTCOME MEASURES Survival, cardiac transplantation, recovery of ventricular function, and persistence of dysrhythmias. RESULTS Freedom from death or cardiac transplantation was 86% at one month and 79% after two years. Five deaths occurred within 72 hours of admission, and one late death at 1.9 years. Extracorporeal membrane oxygenation support was used in four patients, and three patients underwent heart replacement. 34 patients were treated with intravenous corticosteroids. In the survivor/non-cardiac transplantation group (n = 29), the median follow up was 19 months (range 1.2–131.6 months), and the median period for recovery of a left ventricular ejection fraction to > 55% was 2.8 months (range 0–28 months). The mean (SD) final left ventricular ejection and shortening fractions were 66 (9)% and 34 (8)%, respectively. Two patients had residual ventricular dysfunction. No patient required antiarrhythmic treatment. All survivors reported no cardiac symptoms or restrictions in physical activity. CONCLUSIONS Our experience documents good outcomes in paediatric patients presenting with acute heart failure secondary to acute lymphocytic myocarditis treated with immunosuppression. Excellent survival and recovery of ventricular function, with the absence of significant arrhythmias, continued cardiac medications, or restrictions in physical activity were the normal outcomes.

Incidence of secondary pulmonary hypertension in adults with atrial septal or sinus venosus defects

Abstract: OBJECTIVE To examine the incidence of raised pulmonary artery pressure and resistance in adults with isolated atrial septal defect within the oval fossa (so called secundum defect) or sinus venosus defect. DESIGN A historical, retrospective, unrandomised study. SETTING A tertiary referral centre. METHODS Cardiac catheterisation was performed in all patients, with measurement of pulmonary artery pressure and resistance. Pulmonary to systemic flow ratio was calculated using the Fick principle. Pulmonary hypertension was defined as mean pulmonary artery pressure > 30 mm Hg, and increased resistance as an Rp/Rs ratio > 0.3. PATIENTS All patients with a secundum atrial septal or sinus venosus defect who presented between July 1988 and December 1997 were enrolled in the study. RESULTS Pulmonary artery pressure and resistance in the patients with sinus venosus defect (n = 31) was higher than in patients with atrial septal defect (n = 138). Pulmonary hypertension was present in 26% of patients with sinus venosus and in 9% of patients with atrial septal defect. The incidence of raised pulmonary vascular resistance was 16% in patients with sinus venosus and 4% in patients with atrial septal defect. The increase in resistance occurred at a younger age in sinus venosus defect than in atrial septal defect. CONCLUSIONS Patients with sinus venosus defect have higher pulmonary pressures and resistances and develop these complications at younger age than patients with atrial septal defects. Thus they should be managed differently than patients with “simple” atrial septal defects.

Stent implantation for aortic coarctation and recoarctation

Abstract: OBJECTIVE—To determine the early results of balloon expandable stent implantation for aortic coarctation or recoarctation. DESIGN—Prospective observational study. SETTING—Two paediatric cardiology tertiary referral centres. PATIENTS—17 patients, median age 17 years (range 4.4 to 45) and median weight 61 kg (17 to 92). Six had native aortic coarctation and 11 had aortic recoarctation; 14 had upper limb systolic hypertension. Of those with recoarctation, eight had had at least one previous balloon dilatation attempt and two of these patients also had further surgical interventions. INTERVENTION—Balloon expandable Palmaz iliac stent implantation. MAIN OUTCOME MEASURES—Systolic pressures gradients, minimum aortic diameter, upper limb blood pressures, and incidence of aneurysm formation. RESULTS—18 stents were implanted during 18 procedures in the 17 patients. Mean peak systolic pressure gradient fell from 26 mm Hg (95% confidence interval (CI), 21 to 31 mm Hg) before to 5 mm Hg (2 to 8 mm Hg) after stent implantation (p < 0.001), and mean minimum aortic diameter increased from 7 mm (95% CI, 6 to 8 mm) before to 11.3 mm (10 to 12.6 mm) after implantation (p < 0.001). Complications occurred in five patients (bleeding in two, stent migration in two, and aneurysm formation in one). Two patients remained borderline hypertensive and eight were receiving antihypertensive treatment at most recent assessment. CONCLUSIONS—Stent implantation for aortic recoarctation and native coarctation gives good immediate results. Careful follow up is necessary to evaluate complications and the long term effect on blood pressure. Keywords: coarctation; aortic recoarctation; stents

Abnormalities in liver function and coagulation profile following the Fontan procedure

Abstract: OBJECTIVE To investigate liver function and coagulation disorders in patients with a Fontan circulation at different time intervals after surgery. DESIGN Retrospective analysis of clinical data and cross sectional study relating liver function and coagulation profile to time since surgery, in 28 surviving patients after the modified Fontan procedure. PATIENTS 20 patients (71%) with atriopulmonary anastomosis, seven (25%) with atrioventricular anastomosis, and one (4%) with total cavopulmonary connection. Follow up ranged from 2.0 to 21.8 years (mean 11.1). RESULTS Abnormal liver function tests, mainly reflecting cholestasis, were present in 21 patients who had a significantly longer follow up (p CONCLUSIONS Mild cholestasis was mainly present in Fontan patients with a long duration of follow up. Along with laboratory procoagulant abnormalities indicating a prethrombotic state, anticoagulant abnormalities were also present. The coagulation profile varied at different time intervals after surgery. Thus detailed evaluation should be performed regularly, and the use of anticoagulants should be considered in every patient. Long term prospective studies are needed to evaluate the individual fluctuations of coagulation profile over time following a Fontan procedure.

Clinical outcome of patients treated with spinal cord stimulation for therapeutically refractory angina pectoris

Abstract: OBJECTIVE To determine morbidity and mortality characteristics in patients treated with electrical neuromodulation for refractory angina pectoris. DESIGN A retrospective multicentre study of patients treated with spinal cord stimulation between 1987 and 1997; 21 centres were contacted and 14 responded. SETTING Specialist centres worldwide. PATIENTS Questionnaires were returned on 517 patients, of whom 71% were male. One was lost to follow up. Mean (SD) age was 63.9 (10.1) years. Duration of angina pectoris was 8.1 (6.3) years. RESULTS Before spinal cord stimulation, 66% of the patients had experienced myocardial infarction, 68% had three vessel disease, and in 24% the left ventricular ejection fraction (LVEF) was ⩽ 40%. Percutaneous transluminal coronary angioplasty and bypass surgery were performed in 17% and 58% of the subjects, respectively. During a median follow up of 23 months (range 0 to 128), 103 patients died (52 from a cardiac cause, 25 from a non-cardiac cause, and 26 from an unknown cause). Annual all cause mortality was 7–8%; annual cardiovascular fatality was 3.5–5%. Mortality was univariately related to sex, number of diseased vessels, number of revascularisation procedures, previous myocardial infarction, LVEF, insulin dependent diabetes, β blocking agents, and angiotensin converting enzyme inhibitors. Multiple variate analysis showed that LVEF, sex, β blockers, and age ⩾ 71 years were independent predictors of mortality. During spinal cord stimulation, New York Heart Association functional class improved from 3.5 to 2.1 (p v 37%). CONCLUSIONS The clinical outcome of patients with intractable angina is not adversely affected by the chronic use of neurostimulation.

Serum total homocysteine and coronary heart disease: prospective study in middle aged men

Abstract: OBJECTIVES To examine the prospective relation between total homocysteine and major coronary heart disease events. DESIGN A nested case–control study carried out within the British regional heart study, a prospective investigation of cardiovascular disease in men aged 40–59 years at entry. Serum total homocysteine concentrations were analysed retrospectively and blindly in baseline samples from 386 cases who had a myocardial infarct during 12.8 years of follow up and from 454 controls, frequency matched by age and town. RESULTS Geometric mean serum total homocysteine was slightly higher in cases (14.2 μmol/l) than in controls (13.5 μmol/l), a proportional difference of 5.5% (95% confidence interval (CI) −0.02% to 10.8%, p = 0.06). Age adjusted risk of myocardial infarction increased weakly with log total homocysteine concentration; a 1 SD increase in log total homocysteine (equivalent to a 47% increase in total homo cysteine) was associated with an increase in odds of myocardial infarction of 1.15 (95% CI 1.00 to 1.32; p = 0.05). The relation was particularly marked in the top fifth of the total homocysteine distribution (values >16.5 μmol/l), which had an odds ratio of 1.77 (95% CI 1.28 to 2.42) compared with lower levels. Adjustment for other risk factors had little effect on these findings. Total homocysteine concentrations more than 16.5 μmol/l accounted for 13% of the attributable risk of myocardial infarction in this study population. Serum total homocysteine among control subjects varied between towns and was correlated with town standardised mortality ratios for coronary heart disease ( r = 0.43, p = 0.08). CONCLUSIONS Serum total homocysteine is prospectively related to increased coronary risk and may also be related to geographical variation in coronary risk within Britain. These results strengthen the case for trials of total homocysteine reduction with folate.

Chronic infection with Helicobacter pylori, Chlamydia pneumoniae, or cytomegalovirus: population based study of coronary heart disease

Abstract: OBJECTIVE—To study possible associations between coronary heart disease and serological evidence of persistent infection with Helicobacter pylori, Chlamydia pneumoniae, or cytomegalovirus. DESIGN—Population based, case-control study, nested within a randomised trial. SETTING—Five general practices in Bedfordshire, UK. INDIVIDUALS—288 patients with incident or prevalent coronary heart disease and 704 age and sex matched controls. RESULTS—High concentrations of serum IgG antibodies to H pylori were present in 54% of cases v 46% of controls, with corresponding results for C pneumoniae seropositivity (33% v 33%), and cytomegalovirus seropositivity (40% v 31%). After adjustments for age, sex, smoking, indicators of socioeconomic status, and standard risk factors, the odds ratios (95% confidence intervals) for coronary heart disease of seropositivity to these agents were: 1.28 (0.93 to 1.75) for H pylori, 0.95 (0.66 to 1.36) for C pneumoniae, and 1.40 (0.96 to 2.05) for cytomegalovirus. CONCLUSIONS—There is no good evidence of strong associations between coronary heart disease and serological markers of persistent infection with H pylori, C pneumoniae, or cytomegalovirus. To determine the existence of moderate associations between these agents and disease, however, larger scale studies will be needed that can keep residual confounders to a minimum. Keywords: ischaemic heart disease; Helicobacter pylori; Chlamydia pneumoniae; cytomegalovirus