Showing papers in "Heart in 1998"

Preventable causative factors leading to hospital admission with decompensated heart failure

Abstract: Objective To determine the distribution and importance of various factors, especially the preventable ones, that contribute to cardiac decompensation and subsequent hospital admission for heart failure. Methods During a one year period patients were prospectively recruited and evaluated during their hospital stay by means of a structured personal interview by trained medical staff and through clinical examination and laboratory investigation. Setting The cardiological department at a teaching affiliated general community hospital in Berlin, Germany. Patients Consecutive sample of 179 patients admitted to hospital with acute decompensation of pre-existing heart failure. Main outcome measures Proportional distribution of causative factors leading to hospital admission for heart failure; relative importance of preventable factors; details of patient compliance with diet and medication, and knowledge about medication. Results Mean (SD) age was 75.4 (9.9) years. Potential causative factors for decompensated heart failure were identified in 85.5% of patients. Lack of adherence to the medical regimen was the most commonly identified factor and was regarded as the cause of the cardiac decompensation in 41.9% of cases. Non-compliance with drugs was found in 23.5% of patients. Other factors related to hospital admission were coronary ischaemia (13.4%), cardiac arrhythmias (6.1%), uncontrolled hypertension (5.6%), and inadequate preadmission treatment (12.3%). In all, 54.2% of admissions could be regarded as preventable. Conclusions Many hospital admissions for decompensation of chronic heart failure in patients at a district hospital in Berlin are preventable. Measures are necessary to improve this situation and evaluation of programmes that include patient education, patient follow up, and physician training is needed.

Cost effective management programme for heart failure reduces hospitalisation.

Abstract: Objective—To study the effects of a management programme on hospitalisation and health care costs one year after admission for heart failure. Design—Prospective, randomised trial. Setting—University hospital with a primary catchment area of 250 000 inhabitants. Patients—190 patients (aged 65-84 years, 52.3% men) hospitalised because of heart failure. Intervention—Two types of patient management were compared. The intervention group received education on heart failure and self management, with follow up at an easy access, nurse directed outpatient clinic for one year after discharge. The control group was managed according to routine clinical practice. Main outcome measures—Time to readmission, days in hospital, and health care costs during one year. Results—The one year survival rate was 71.8% (n = 79) in the control group and 70.0% (n = 56) in the intervention group (NS). The mean time to readmission was longer in the intervention group than in the control group (141 (87) v 106 (101); p < 0.05) and number of days in hospital tended to be fewer (4.2 (7.8) v 8.2 (14.3); p = 0.07). There was a trend towards a mean annual reduction in health care costs per patient of US$1300 (US$1 = SEK 7.76) in the intervention group compared with costs in the controls (US$3594 v 2294; p = 0.07). Conclusions—A management programme for patients with heart failure discharged after hospitalisation reduces health care costs and the need for readmission. Keywords: heart failure; hospitalisation; management; health care costs; nurse led clinics

Five minute recordings of heart rate variability for population studies: repeatability and age–sex characteristics

Abstract: Objective To evaluate the stability of short recordings of heart rate variability (HRV) with time, and the association of HRV with age and sex. Design Five minute Holter recordings were made twice over a two month interval (tracking study). In addition, HRV was measured in a cross sectional study. Setting Residents of 11 Israeli kibbutzim were examined in their settlements. Subjects 32 men and 38 women (aged 31–67) participated in the tracking study and 294 (aged 35–65) were involved in the cross sectional study. Main outcome measures Time and frequency domain analyses on Holter recordings were undertaken in two breathing conditions: spontaneous and controlled breathing (15 respirations per minute). Regression was used to assess the relations of sex, age, heart rate, and logarithmically transformed HRV indices. Results HRV measures were highly consistent with time with correlations of 0.76–0.80 for high frequency and total power. Geometric mean total power declined with age by 45% in men and 32% in women, and was lower by 24% among women than among men (all p ⩽ 0.005). Men had a 34% higher very low and low frequency power and a higher ratio of low to high frequency power (p Conclusion Short recordings of HRV in a non-laboratory setting are stable over months and therefore characteristic of an individual. Strong age and sex effects were evident. HRV derived from short recordings can be informative in population based studies.

Reproducibility and responsiveness of quality of life assessment and six minute walk test in elderly heart failure patients

Abstract: Objective—To examine the reproducibility and responsiveness to change of a six minute walk test and a quality of life measure in elderly patients with heart failure. Design—Longitudinal within patient study. Subjects—60 patients with heart failure (mean age 82 years) attending a geriatric outpatient clinic, 45 of whom underwent a repeat assessment three to eight weeks later. Main outcome measures—Subjects underwent a standardised six minute walk test and completed the chronic heart failure questionnaire (CHQ), a heart failure specific quality of life questionnaire. Intraclass correlation coefficients (ICC) were calculated using a random effects one way analysis of variance as a measure of reproducibility. Guyatt's responsiveness coefficient and effect sizes were calculated as measures of responsiveness to change. Results—24 patients reported no major change in cardiac status, while seven had deteriorated and 14 had improved between the two clinic visits. Reproducibility was satisfactory (ICC > 0.75) for the six minute walk test, for the total CHQ score, and for the dyspnoea, fatigue, and emotion domains of the CHQ. Effect sizes for all measures were large (> 0.8), and responsiveness coefficients were very satisfactory (> 0.7). Effect sizes for detecting deterioration were greater than those for detecting improvement. Conclusions—Quality of life assessment and a six minute walk test are reproducible and responsive measures of cardiac status in frail, very elderly patients with heart failure. Keywords: six minute walk; elderly people; heart failure; quality of life

Fetal tachycardias: management and outcome of 127 consecutive cases

Abstract: Objective—To review the management and outcome of fetal tachycardia, and to determine the problems encountered with various treatment protocols. Study design—Retrospective analysis. Subjects—127 consecutive fetuses with a tachycardia presenting between 1980 and 1996 to a single tertiary centre for fetal cardiology. The median gestational age at presentation was 32 weeks (range 18 to 42). Results—105 fetuses had a supraventricular tachycardia and 22 had atrial flutter. Overall, 52 fetuses were hydropic and 75 non-hydropic. Prenatal control of the tachycardia was achieved in 83% of treated non-hydropic fetuses compared with 66% of the treated hydropic fetuses. Digoxin monotherapy converted most (62%) of the treated non-hydropic fetuses, and 96% survived through the neonatal period. First line drug treatment for hydropic fetuses was more diverse, including digoxin (n = 5), digoxin plus verapamil (n = 14), and flecainide (n = 27). The response rates to these drugs were 20%, 57%, and 59%, respectively, confirming that digoxin monotherapy is a poor choice for the hydropic fetus. Response to flecainide was faster than to the other drugs. Direct fetal treatment was used in four fetuses, of whom two survived. Overall, 73% (n = 38) of the hydropic fetuses survived. Postnatally, 4% of the non-hydropic group had ECG evidence of pre-excitation, compared with 16% of the hydropic group; 57% of non-hydropic fetuses were treated with long term antiarrhythmics compared with 79% of hydropic fetuses. Conclusions—Non-hydropic fetuses with tachycardias have a very good prognosis with transplacental treatment. Most arrhythmias associated with fetal hydrops can be controlled with transplacental treatment, but the mortality in this group is 27%. At present, there is no ideal treatment protocol for these fetuses and a large prospective multicentre trial is required to optimise treatment of both hydropic and non-hydropic fetuses. Keywords: fetal tachycardia; atrial flutter; supraventricular tachycardia

Secondary prevention in coronary heart disease: a randomised trial of nurse led clinics in primary care

Abstract: Objective—To evaluate whether nurse run clinics in general practice improve secondary prevention in patients with coronary heart disease. Design—Randomised controlled trial. Setting—A random sample of 19 general practices in northeast Scotland. Patients—1173 patients (685 men and 488 women) under 80 years with working diagnoses of coronary heart disease, but without terminal illness or dementia and not housebound. Intervention—Nurse run clinics promoted medical and lifestyle aspects of secondary prevention and offered regular follow up. Main outcome measures—Components of secondary prevention assessed at baseline and one year were: aspirin use; blood pressure management; lipid management; physical activity; dietary fat; and smoking status. A cumulative score was generated by counting the number of appropriate components of secondary prevention for each patient. Results—There were significant improvements in aspirin management (odds ratio 3.22, 95% confidence interval 2.15 to 4.80), blood pressure management (5.32, 3.01 to 9.41), lipid management (3.19, 2.39 to 4.26), physical activity (1.67, 1.23 to 2.26) and diet (1.47, 1.10 to 1.96). There was no effect on smoking cessation (0.78, 0.47 to 1.28). Of six possible components of secondary prevention, the baseline mean was 3.27. The adjusted mean improvement attributable to intervention was 0.55 of a component (0.44 to 0.67). Improvement was found regardless of practice baseline performance. Conclusions—Nurse run clinics proved practical to implement in general practice and effectively increased secondary prevention in coronary heart disease. Most patients gained at least one effective component of secondary prevention and, for them, future cardiovascular events and mortality could be reduced by up to a third. Keywords: coronary heart disease; secondary prevention; randomised controlled trial; nurse led clinics

Prognostic value of ECG findings for total, cardiovascular disease, and coronary heart disease death in men and women.

Abstract: Objective To study abnormalities in the resting ECG as independent predictors for all cause, cardiovascular disease (CVD), and coronary heart disease (CHD) mortality in a population based random sample of men and women, and to explore whether their prognostic value is different between sexes. Design and subjects An age and sex stratified random sample was selected from the total Belgian population aged 25 to 74 years. Baseline data were gathered and resting ECGs were classified according to Minnesota code criteria. The sample was then followed for at least 10 years with respect to cause specific death. Results are based on observations from 5208 men and 4746 women free from prevalent CHD at the start of the follow up period. Results Although the prevalence of major abnormalities in general was comparable between sexes, women had more ischaemic findings, ST segment changes, and abnormal T waves on their baseline ECG, while men showed more arrhythmias, bundle branch blocks, and left ventricular hypertrophy. Fitting the multiplicative effect on subsequent mortality between all ECG classifications under study and sex indicated that the prognostic value of ECG changes was equal in women and men. Independently of other risk factors and other major ECG changes, almost all ECG classifications were significantly related to all cause, CVD, and CHD mortality. The most predictive ECG findings for CVD death were ST segment depression (risk ratio (RR) 4.71), major ECG findings (RR 3.26), left ventricular hypertrophy (RR 2.79), bundle branch blocks (RR 2.58), T wave flattening (RR 2.47), ischaemic ECG findings (RR 2.35), and arrhythmias (RR 2.15). The prognostic value of major ECG findings for CVD and CHD death was more powerful than well established cardiovascular risk factors. Conclusions Abnormalities in the baseline ECG are strongly associated with subsequent all cause, CVD, and CHD mortality. Their predictive value was similar for men and women.

Midodrine: a role in the management of neurocardiogenic syncope

Abstract: Objective—To determine the benefit of midodrine, an α agonist, on symptom frequency and haemodynamic responses during head up tilt in patients with neurocardiogenic syncope. Setting—Cardiovascular investigation unit (a secondary and tertiary referral centre for the investigation and management of syncope). Patients—16 outpatients (mean (SD) age 56 (18) years; five men) with frequent hypotensive symptoms (more than two syncopal episodes and fewer than 20 symptom free days per month), and reproducible syncope with glyceryl trinitrate (GTN) during head up tilt. Design and intervention—Randomised double blind placebo controlled study. Patients were randomised to receive either placebo or midodrine for one month. Symptom events were recorded during each study month. At the end of each study month patients completed a quality of life scoring scale (Short Form 36) and a global assessment of therapeutic response. They received GTN with head up tilt for measurement of heart rate (electrocardiography), phasic blood pressure (digital photoplethysmography), and thoracic fluid index (transthoracic impedance plethysmography) during symptom provocation. Results—Patients administered midodrine had an average of 7.3 more symptom free days than those who received placebo (95% confidence interval (CI) 4.6 to 9; p < 0.0001). Eleven patients reported a positive therapeutic response with midodrine (p = 0.002). All domains of quality of life showed improvement with midodrine, in particular physical function (8.1; 95% CI 3.7 to 12.2), energy and vitality (14.6; 95% CI 7.3 to 22.1), and change in health status (22.2; 95% CI 11 to 33.4 ). Fourteen patients who were given placebo had tilt induced syncope compared with six given midodrine (p = 0.01). Baseline supine systolic blood pressure was higher and heart rate lower in patients who received midodrine than in those who were given placebo ( p < 0.05). A lower thoracic fluid index in patients administered midodrine indicates increased venous return when supine and during head up tilt. There were no serious adverse effects. Conclusions—Midodrine had a conspicuous beneficial effect on symptom frequency, symptoms during head up tilt, and quality of life. Midodrine is recommended for the treatment of neurocardiogenic syncope in patients with frequent symptoms. Keywords: midodrine; neurocardiogenic syncope; head up tilt test

Long term intravenous prostaglandin (epoprostenol or iloprost) for treatment of severe pulmonary hypertension

Abstract: Objective To investigate the relation between the severity of pulmonary hypertension and the outcome of medical treatment. Methods 98 patients with primary pulmonary hypertension—nine (6%) with systemic disease and pulmonary hypertension and 39 (27%) with thromboembolic pulmonary hypertension—received medical treatment and were followed between 1982 and 1995. They were given long term intravenous prostaglandin treatment (either epoprostenol (n = 61) or iloprost (n = 13)) or conventional treatment with oral anticoagulants (n = 24) with or without calcium channel blockers. Event-free survival was measured to death or transplant surgery, or pulmonary thromboendarterectomy. Results Prognosis (hazard ratio) was affected by: New York Heart Association grade, 1.52 (95% confidence interval 1.11 to 2.09); mixed venous oxygen saturation (Svo 2 %), 0.97 (0.95 to 0.98); cardiac index, 0.72 (0.49 to 1.06); mean right atrial pressure, 1.04 (1.01 to 1.07); and pulmonary vascular resistance, 1.02 (1.00 to 1.04). The median event-free survival time of patients with Svo 2 2 ⩾ 60% between conventional treatment and prostaglandin treatment, survival being 1275 days (732 to 1818; (n = 48)) and 986 days (541 to 1431; n = 30)), respectively. Capacity for pulmonary vasodilatation did not predict outcome of treatment. Conclusions Continuous intravenous prostaglandins were more effective than anticoagulants, with or without calcium channel blockers, in prolonging survival in patients with right heart failure. In these patients a capacity to vasodilate did not predict outcome from medical treatment.

Superiority of ibutilide (a new class III agent) over DL-sotalol in converting atrial flutter and atrial fibrillation. The Ibutilide/Sotalol Comparator Study Group.

Abstract: Objective—To compare the efficacy and safety of a single dose of ibutilide, a new class III antiarrhythmic drug, with that of DL-sotalol in terminating chronic atrial fibrillation or flutter in haemodynamically stable patients. Design—Double blind, randomised study. Setting—43 European hospitals. Patients—308 patients (mean age 60 years, 70% men, 48% with heart disease) with sustained atrial fibrillation (n = 251) or atrial flutter (n = 57) (duration three hours to 45 days) were randomised to three groups to receive a 10 minute infusion of 1 mg ibutilide (n = 99), 2 mg ibutilide (n = 106), or 1.5 mg/kg DL-sotalol (n = 103). Infusion was discontinued at termination of the arrhythmia. Main outcome measure—Successful conversion of atrial fibrillation or flutter, defined as termination of arrhythmia within one hour of treatment. Results—Both drugs were more effective against atrial flutter than against atrial fibrillation. Ibutilide was superior to DL-sotalol for treating atrial flutter (70% and 56% v 19%), while the high dose of ibutilide was more effective for treating atrial fibrillation than DL-sotalol (44% v 11%) and the lower dose of ibutilide (44% v 20%, p < 0.01). The mean (SD) time to arrhythmia termination was 13 (7) minutes with 2 mg ibutilide, 19 (15) minutes with 1 mg ibutilide, and 25 (17) minutes with DL-sotalol. In all patients, the duration of arrhythmia before treatment was a predictor of arrhythmia termination, although this was less obvious in the group that received 2 mg ibutilide. This dose converted almost 48% of atrial fibrillation that was present for more than 30 days. Concomitant use of digitalis or nifedipine and prolongation of the QTc interval were not predictive of arrhythmia termination. Bradycardia (6.5%) and hypotension (3.7%) were more common side effects with DL-sotalol. Of 211 patients given ibutilide, two (0.9%) who received the higher dose developed polymorphic ventricular tachycardia, one of whom required direct current cardioversion. Conclusion—Ibutilide (given in 1 or 2 mg doses over 10 minutes) is highly effective for rapidly terminating persistent atrial fibrillation or atrial flutter. This new class III drug, under monitored conditions, is a potential alternative to currently available cardioversion options. Keywords: atrial fibrillation; atrial flutter; antiarrhythmic agents; ibutilide; sotalol

Amiodarone and the thyroid: a practical guide to the management of thyroid dysfunction induced by amiodarone therapy

Abstract: Amiodarone induces predictable changes in thyroid function tests that are largely explicable in terms of the physiological effects of iodide excess and inhibition of deiodinase activity. Clinically relevant thyroid dysfunction is not uncommon during amiodarone therapy, and requires careful diagnosis and treatment. The diagnosis and management of thyrotoxicosis is probably best supervised by a specialist endocrinologist. Control of hypothyroidism can generally be achieved simply by the addition of T4 to the therapeutic regimen, ideally after an initial assessment by an endocrinologist. The frequency with which amiodarone causes thyroid and other complications serves to emphasize the need for rational prescribing and long-term cardiological follow up.

Late complications following permanent pacemaker implantation or elective unit replacement

Abstract: Objective—To determine the rate of late complications following first implantation or elective unit replacement of a permanent pacemaker system. Design—Analysis of pacemaker data and complications prospectively acquired on a computerised database. Complications were studied over an 11 year period from January 1984 to December 1994. Setting—Tertiary referral cardiothoracic centre. Patients—Records of 2621 patients were analysed retrospectively. Main outcome measures—Complications requiring repeat procedures occurring more than six weeks after pacemaker implantation or elective unit replacement. Results—The overall rate of late complications was significantly lower after first implantation of a permanent pacemaker (34 cases, complication rate 1.4%, 95% confidence interval 0.9% to 1.9%) than after elective unit replacement (16 cases, complication rate 6.5% (3.3% to 9.7%). There were 20 cases of erosion, 18 infections, five electrode problems, and seven miscellaneous problems. Complications were more common with inexperienced operators (18.9% (6.0% to 31.8%)) than with experienced operators (0.9% (0.3% to 1.5%)). Conclusions—The incidence of late complications following pacemaker implantation is low and compares favourably with early complication rates. The majority are caused by erosion and infection. Patients who have undergone elective unit replacement are at particular risk. Keywords: permanent pacemaker; elective unit replacement; late complications; arrhythmias

Predictive value of dobutamine echocardiography and positron emission tomography in identifying hibernating myocardium in patients with postischaemic heart failure

Abstract: Objective—To compare the predictive value of dobutamine echocardiography (DE) and positron emission tomography (PET) in identifying reversible chronic left ventricular (LV) dysfunction (hibernating myocardium) in patients with coronary artery disease (CAD) and overt heart failure. Patients—30 patients (four women) with CAD and heart failure undergoing coronary artery bypass grafting (CABG). Methods—Myocardial viability was assessed with DE (5 and 10 µg/kg/min) and PET with [ 18 F] 2-fluoro-2-deoxy-Dglucose (FDG) under hyperinsulinaemic euglycaemic clamp. Regional (echo) and global LV function (MUGA) were assessed at baseline and six months after CABG. Results—192 of the 336 (57%) dysfunctional LV segments improved function following CABG (hibernating) and the LV ejection fraction (EF) increased from 23(7) to 32(9)% (p 5%). DE and PET had similar positive predictive values (68% and 66%) in the identification of hibernating myocardium, but DE had a significantly lower negative predictive value than PET (54% v 96%; p 5%, whereas the number of DE viable segments, the baseline LVEF, and wall motion were not. Conclusions—DE has a higher false negative rate than PET in identifying recoverable LV dysfunction in patients with severe postischaemic heart failure. The amount of PET viable myocardium correlates with the functional outcome following CABG. (Heart 1998;79:281‐288)

Coronary event and case fatality rates in an English population: results of the Oxford myocardial infarction incidence study. The Oxford Myocardial Infarction Incidence Study Group.

Abstract: Objectives—To determine coronary event and case fatality rates in an English population aged less than 80 years in Oxfordshire, and to compare these rates with those reported by the UK monitoring trends and determinants of cardiovascular disease (MONICA) centres in Scotland and Northern Ireland and those ascertained in Oxfordshire in 1966-67. Design—A population wide surveillance study conducted in 1994-95 using prospective and retrospective case ascertainment. Setting—A resident population in Oxfordshire of 568 800. Subjects—Patients with suspected myocardial infarction or coronary death. Outcome measures—A diagnosis of definite or possible myocardial infarction or coronary death using WHO MONICA diagnostic criteria based on symptoms, electrocardiograms, cardiac enzymes, necropsy findings, and past medical history. Results—The annual rate for a first or recurrent coronary event per 100 000 population aged less than 65 years in 1994-95 was 273 for men and 66 for women after age adjustment to a standard world population. Rates in the age group 65-79 years were 1350 for men and 677 for women. Between 1966-67 and 1994-95, the age standardised event rate in the age group 30-69 years decreased significantly by 33% (95% confidence interval (CI) 44 to 21) in men, and there was a non-significant reduction of 8% (95% CI −33 to 17) in women. The age standardised 28 day case fatality rates also decreased significantly by 28% (95% CI 41 to 15) in men and by 32% (95% CI 55 to 9) in women. Conclusions—The coronary event rate in Oxfordshire was much lower than rates reported by MONICA centres in Glasgow and Belfast, and similar to rates reported by MONICA centres in France and northern Italy. The substantially lower event rate accounts for lower coronary heart disease mortality in Oxfordshire than in Scotland and Northern Ireland. The reduced coronary mortality in this region is attributable to declines in coronary event and case fatality rates. Keywords: myocardial infarction; coronary heart disease; incidence; case fatality

Prevalence of atrial fibrillation in the general population and in high-risk groups

Abstract: Atrial fibrillation (AF) is the commonest cardiac arrhythmia and is associated with high risk of embolic stroke, which can be reduced by anticoagulation. To have an impact on the population as a whole, patients must first be identified, and screening would be most cost-effective if targeted on patients at high risk of the condition. We have investigated the prevalence of AF in different age groups in the general population, and in those in high risk groups. Methods: We have analysed the prevalence of AF and associated echocardiographic risk actors in patients in the following groups: Random population sample, aged 45+; existing clinical diagnosis of heart failure (made by GP); previous MI; hypertension; angina; and diabetes. Patients were assessed clinically and with ECG and echocardiography, as part of a large heart failure epidemiology study. Results: The table details the prevalence of AF in the patient groups. Other associated risk factors for embolic stroke (mitral valve disease, left atrial enlargement or impaired LV function) are also listed, and the proportion anticoagulated at the time of screening. AF Abnormal echo in pts with AF On warfarin Population aged 45+ 43/2552 (1.7%) 29/43 (67%) 9/43 (21%) of which: 45-54 1/858 (0.1%) 1/1 (100%) 1/1 (100%) 55-64 7/785 (0.9%) 2/7 (29%) 1/7 (14%) 65-74 9/615 (1.5%) 6/9 (67%) 4/9 (44%) 75+ 26/294 (8.8%) 20/26 (77%) 3/26 (12%) Clinical heart failure 69/279 (24.7%) 61/69 (88%) 24/69 (35%) Previous MI 8/117 (6.8%) 6/8 (75%) 3/8 (37%) Hypertension 5/192 (2.6%) 2/5 (40%) 1/5 (20%) Angina 4/120 (3.3%) 3/4 (75%) 2/4 (50%) Diabetes 3/58 (5.2%) 3/3 (100%) 2/3 (67%) Conclusions: AF prevalence in the population sample was 1.7%, and in the high-risk groups overall was 11.6%; these patients had other embolic risk factors more frequently also. Targeting screening on such patients would identify many patients at high stroke risk.

Prognostic value of non-sustained ventricular tachycardia and the potential role of amiodarone treatment in hypertrophic cardiomyopathy: assessment in an unselected non-referral based patient population

Abstract: Background Amiodarone has been reported to reduce the likelihood of sudden death in patients with hypertrophic cardiomyopathy (HCM). However, data regarding the clinical course in HCM have traditionally come from selected referral populations biased toward assessment of high risk patients. Aims To evaluate antiarrhythmic treatment for sudden death in an HCM population not subject to tertiary referral bias, closely resembling the true disease state present in the community. Methods Cardiovascular mortality was assessed in relation to the occurrence of non-sustained ventricular tachycardia (NSVT) on 24 or 48 hour ambulatory Holter recording, a finding previously regarded as a marker for sudden death, particularly when the arrhythmia was frequent, repetitive or prolonged. 167 consecutive patients were analysed by multiple Holter ECG recordings (mean (SD) 157 (129) hours) and followed for a mean of 10 (5) years. Only patients with multiple repetitive NSVT were treated with amiodarone, and in relatively low doses (220 (44) mg/day). Results Nine HCM related deaths occurred: 8 were the consequence of congestive heart failure, but only 1 was sudden and unexpected. Three groups of patients were segregated based on their NSVT profile: group 1 (n = 39), multiple (⩾ 2 runs) and repetitive bursts (on ⩾ 2 Holters) of NSVT, or prolonged runs of ventricular tachycardia, included 4 deaths due to heart failure; group 2 (n = 38), isolated infrequent bursts of NSVT, included 1 sudden death; group 3 (n = 90), without NSVT, included 4 heart failure deaths. Kaplan-Meier survival analysis showed no significant differences in survival between the three groups throughout follow up. Conclusions In an unselected patient population with HCM, isolated, non-repetitive bursts of NSVT were not associated with adverse prognosis and so this arrhythmia does not appear to justify chronic antiarrhythmic treatment. Amiodarone, administered in relatively low doses, did not carry an independent and additive risk for cardiac mortality. Amiodarone may have contributed to the absence of sudden cardiac death in patients believed to be at higher risk because of multiple repetitive NSVT.

Characterisation of coronary atherosclerotic morphology by spectral analysis of radiofrequency signal: in vitro intravascular ultrasound study with histological and radiological validation

Abstract: Objective To determine whether spectral analysis of unprocessed radiofrequency (RF) signal offers advantages over standard videodensitometric analysis in identifying the morphology of coronary atherosclerotic plaques. Methods 97 regions of interest (ROI) were imaged at 30 MHz from postmortem, pressure perfused (80 mm Hg) coronary arteries in saline baths. RF data were digitised at 250 MHz. Two different sizes of ROI were identified from scan converted images, and relative amplitudes of different frequency components were analysed from raw data. Normalised spectra was used to calculate spectral slope (dB/MHz), y-axis intercept (dB), mean power (dB), and maximum power (dB) over a given bandwidth (17–42 MHz). RF images were constructed and compared with comparative histology derived from microscopy and radiological techniques in three dimensions. Results Mean power was similar from dense fibrotic tissue and heavy calcium, but spectral slope was steeper in heavy calcium (−0.45 (0.1)) than in dense fibrotic tissue (−0.31 (0.1)), and maximum power was higher for heavy calcium (−7.7 (2.0)) than for dense fibrotic tissue (−10.2 (3.9)). Maximum power was significantly higher in heavy calcium (−7.7 (2.0) dB) and dense fibrotic tissue (−10.2 (3.9) dB) than in microcalcification (−13.9 (3.8) dB). Y-axis intercept was higher in microcalcification (−5.8 (1.1) dB) than in moderately fibrotic tissue (−11.9 (2.0) dB). Moderate and dense fibrotic tissue were discriminated with mean power: moderate −20.2 (1.1) dB, dense −14.7 (3.7) dB; and y-axis intercept: moderate −11.9 (2.0) dB, dense −5.5 (5.4) dB. Different densities of fibrosis, loose, moderate, and dense, were discriminated with both y-axis intercept, spectral slope, and mean power. Lipid could be differentiated from other types of plaque tissue on the basis of spectral slope, lipid −0.17 (0.08). Also y-axis intercept from lipid (−17.6 (3.9)) differed significantly from moderately fibrotic tissue, dense fibrotic tissue, microcalcification, and heavy calcium. No significant differences in any of the measured parameters were seen between the results obtained from small and large ROIs. Conclusion Frequency based spectral analysis of unprocessed ultrasound signal may lead to accurate identification of atherosclerotic plaque morphology.

Central role of echocardiography in the diagnosis and assessment of heart failure

Abstract: Heart failure is a common condition that is becoming more prevalent1 2 It could be defined as the inability of the heart to deliver a satisfactory output at normal filling pressures It is a complex clinical syndrome, usually marked by progressive breathlessness on effort, and often including systemic venous congestion with resulting oedema and hepatic congestion Clinical heart failure has a poor prognosis,3 and consumes very large amounts of health care resources There are widespread inaccuracies in diagnosis when clinical methods alone are used, and many patients in whom the diagnosis is made in primary care prove not to have the condition on further investigation4-6 There is some evidence of increased use of echocardiography in heart failure in UK hospitals7 It has become clear from recent studies that pharmacological interventions significantly improve outcomes in clinical heart failure due to left ventricular (LV) systolic dysfunction, in asymptomatic LV dysfunction, and following myocardial infarction8-11Echocardiography is a non-invasive technique well suited to the evaluation of LV function, and most echocardiographic departments find that estimation of LV function occupies an increasing proportion of their workload Community studies of LV systolic dysfunction by echocardiography suggest a prevalence of 15–18% in symptomatic patients aged 25–74 years, depending on whether an ejection fraction of 03 or 035 was used as the criterion, with many more than that being asymptomatic12 Almost all patients with symptoms or signs of heart failure, including those postmyocardial infarction, should have an echocardiographic evaluation as early as possible in their clinical course (table 1)4 There may be a few patients in whom, because of frailty or other complex pathology, the investigation would add little to management However, many drugs (such as angiotensin converting enzyme (ACE) inhibitors, digoxin, and potent diuretics) used in the treatment …

Recent activation of the plaque immune response in coronary lesions underlying acute coronary syndromes

Abstract: Objective—To discriminate between chronic inflammation and acute activation of the plaque immune response in culprit lesions of patients with acute coronary syndromes. Design—Retrospective study. Setting—Tertiary referral centre. Subjects—71 patients having coronary atherectomy were classified according to their ischaemic syndrome: stable angina (n = 23); stabilised unstable angina (n = 18); refractory unstable angina (n = 11); and acute myocardial infarction (n = 19). Main outcome measures—Immunohistochemical measurement of interleukin 2 receptor (IL-2R) (CD25) positive cells expressed as a percentage of the total amount of (CD3 positive) T lymphocytes in frozen sections of atherectomy specimens. Results—The number of lesions containing IL-2R (CD25) positive T cells increased with severity of the ischaemic coronary syndrome (stable angina, 52%; stabilised unstable angina, 77.8%; refractory unstable angina, 90.9%; acute myocardial infarction, 89.4%). The percentage of activated T cells (CD25/CD3 ratios ×100) increased in lesions associated with refractory unstable angina (7.8%) and acute myocardial infarction (18.5%),compared with those in lesions associated with either chronic stable angina (2.2%) or stabilised unstable angina (3.3%). Conclusions—An increase in the percentage of IL-2R positive T lymphocytes in culprit lesions of patients with acute coronary syndromes indicates recent activation and amplification of the immune response within plaques. This may result in a burst of inflammatory products with tissue degrading and vasoactive properties and, hence, could initiate or accelerate the onset of an acute coronary event. (Heart 1998;80:14‐18)

Coronary pressure measurement and fractional flow reserve.

Abstract: The shortcomings of coronary arteriography to assess the physiological significance of coronary stenoses have been recognised for decades1 2; therefore, the importance of additional physiological techniques is beyond doubt. One of the currently available physiological techniques is coronary pressure measurement, which has emerged over the past few years as a major step forward in the invasive assessment of coronary artery disease.3-9This was partly owing to major technical progress in developing pressure monitoring guidewires and partly to a theoretical innovation, the concept of coronary pressure derived fractional flow reserve (FFR), which closely relates distal coronary pressure to myocardial blood flow during maximum arteriolar vasodilatation. In the catheterisation laboratory, this new approach enables an “on the spot” diagnosis as to what extent a given epicardial stenosis contributes to reversible myocardial ischaemia and the decision whether revascularisation of the stenosis is warranted. In addition, pressure derived FFR appears to be a useful index to monitor and guide coronary intervention, particularly adequate stent deployment.10 11 This review aims to provide a short overview of the theoretical and physiological background of this new approach and to focus on its clinical applicability, both for diagnostic and therapeutic catheterisation. The functional state of a patient with a coronary artery stenosis is determined by the maximum blood flow that can reach the dependent myocardium. As soon as maximum achievable blood flow, at a given level of exercise, is no longer sufficient to match oxygen demand, myocardial ischaemia and angina pectoris will occur. Therefore, fundamentally, it is maximum blood flow that should be studied to establish the physiological significance of a coronary stenosis. Fractional flow reserve is defined as maximum myocardial blood flow in the presence of a stenosis divided by the theoretical maximum flow in the absence of the stenosis—that is, maximum flow …

Physiological cardiac reserve: development of a non-invasive method and first estimates in man.

Abstract: Objective To investigate whether physiological cardiac reserve can be measured in man without invasive procedures and whether it is a major determinant of exercise capacity. Design Development of method of measurement and an observational study. Setting A regional cardiothoracic centre. Subjects 70 subjects with a wide range of cardiac function, from heart failure patients to athletes. Methods Subjects underwent treadmill, symptom limited cardiopulmonary exercise tests to measure aerobic exercise capacity (represented by V˙o 2 max) and cardiac reserve. Cardiac output was measured non-invasively using the CO 2 rebreathing technique. Results Cardiac power output (CPO max ) at peak exercise was found to be significantly related to aerobic capacity: CPO max (W) = 0.35 + 1.5V˙o 2 max (l/min), r = 0.87, p r = 0.62, p Conclusions A non-invasive method of estimating physiological cardiac reserve was developed. The reserve was found to be a major determinant of exercise capacity in a population of normal subjects and patients with heart disease. This method may thus be used to provide a clearer definition of the extent of cardiac impairment in patients with heart failure.

Screening for atrial fibrillation in primary care

Abstract: Objective—To investigate a population of elderly people for atrial fibrillation and to determine how many of the cases identified might benefit from treatment with anticoagulants. Methods—From a practice of four primary care physicians, 1422 patients aged 65 years and over were identified, of whom 1207 (85% of the total population) underwent electrocardiographic screening to detect the presence of atrial fibrillation. Patients with the arrhythmia were further evaluated by echocardiography and interview, to stratify their risk of stroke based on echocardiographic and clinical risk factors, their perceived risk from anticoagulation, and their attitude towards this treatment. Their primary care physician was also interviewed to determine the factors influencing the prescription of anticoagulants. Results—The arrhythmia occurred in 65 patients (5.4% overall), its prevalence increasing markedly with age (2.3% in 65 to 69 years age group; 8.1% in those over 85). Warfarin was being prescribed to 21.4% of these patients, although the findings of the study indicate that a further 20% were eligible for this treatment. Symptoms suggestive of cardiac failure were common (32.1%) and coexisting pathology was often identified by cardiac ultrasound in these patients (left ventricular hypertrophy, 32.1%; impaired left ventricular contractility, 21.4%; left atrial dilatation, 80.4%; mitral annular calcification, 42.9%; mitral stenosis, 7.1%; mitral regurgitation, 48.2%; aortic stenosis, 8.9%). In all but one case, the decision to anticoagulate was based on the clinical rather than the echocardiographic findings. Conclusions—Individual risk-benefit assessment in elderly patients with atrial fibrillation suggests that almost half (41.4%) are eligible for full anticoagulation with warfarin, whereas presently only one fifth are receiving this treatment. The decision to anticoagulate can be made on clinical grounds in most cases. If these results are confirmed, a doubling of the current number of patients taking anticoagulants can be anticipated. Keywords: atrial fibrillation; primary care; anticoagulant treatment

Myocardial infarction in young people with normal coronary arteries

Abstract: Myocardial infarction occurring in young people with angiographically normal coronary arteries is well described but the pathophysiology of this condition remains unknown. Coronary artery spasm in association with thrombus formation and minimal atheromatous disease or spontaneous coronary artery dissection are possible causes. Two young men presented with severe chest pain after acute alcohol intoxication and each sustained an extensive anterior myocardial infarction. Investigations including intravascular ultrasound showed no evidence of atherosclerotic coronary artery disease. Coronary artery spasm associated with acute alcohol intoxication as well as a prothrombotic state and endothelial damage related to cigarette smoking may be mechanisms leading to acute myocardial infarction in these cases. Acute myocardial infarction occurs in young persons with normal coronary arteries and the diagnosis should be considered in young patients presenting with severe chest pain, particularly those abusing cocaine or alcohol, so that reperfusion therapy can be initiated promptly.

Results of three to 10 year follow up of balloon dilatation of the pulmonary valve

Abstract: Background—The results of immediate and short term follow up of balloon dilatation of the pulmonary valve have been well documented, but there is limited information on long term follow up. Objective—To evaluate the results of three to 10 year follow up of balloon dilatation of the pulmonary valve in children and adolescents. Setting—Tertiary care centre/university hospital. Design—Retrospective study. Methods and results—85 patients (aged between 1 day and 20 years, mean (SD) 7.0 (6.4) years) underwent balloon dilatation of the pulmonary valve during an 11 year period ending August 1994. There was a resultant reduction in the peak to peak gradient from 87 (38) to 26 (22) mm Hg. Immediate surgical intervention was not required. Residual gradients of 29 (17) mm Hg were measured by catheterisation (n = 47) and echo Doppler (n = 82) at intermediate term follow up (two years). When individual results were scrutinised, nine of 82 patients had restenosis, defined as a peak gradient of 50 mm Hg or more. Seven of these patients underwent repeat balloon dilatation of the pulmonary valve: peak gradients were reduced from 89 (40) to 38 (20) mm Hg. Clinical evaluation and echo Doppler data of 80 patients showed that residual peak instantaneous Doppler gradients were 17 (15) mm Hg at long term follow up (three to 10 years, median seven), with evidence for late restenosis in one patient (1.3%). Surgical intervention was necessary to relieve fixed infundibular stenosis in three patients and supravalvar pulmonary stenosis in one. Repeat balloon dilatation was performed to relieve restenosis in two patients. Actuarial reintervention free rates at one, two, five, and 10 years were 94%, 89%, 88%, and 84%, respectively. Pulmonary valve regurgitation was noted in 70 of 80 patients at late follow up, but neither right ventricular dilatation nor paradoxical interventricular septal motion developed. Conclusions—The results of late follow up of balloon dilatation of the pulmonary valve are excellent. Repeat balloon dilatation was performed in 11% of patients and surgical intervention for subvalvlar or supravalvar stenosis in 5%. Most patients had mild residual pulmonary regurgitation but right ventricular volume overload did not develop and surgical intervention was not required. Balloon dilatation is the treatment of choice in the management of moderate to severe stenosis of the pulmonary valve. Further follow up studies should be undertaken to evaluate the significance of residual pulmonary regurgitation. Keywords: balloon dilatation of the pulmonary valve; pulmonary stenosis; pulmonary regurgitation

Treatment of pulmonary hypertension with the continuous infusion of a prostacyclin analogue, iloprost

Abstract: Objective To compare prostacyclin with an analogue, iloprost, in treatment of severe pulmonary hypertension. Patients Eight patients with severe pulmonary hypertension: primary in five, thromboembolic pulmonary hypertension in three. Methods All patients underwent right heart catheterisation. Mean (SEM) right atrial pressure was 9.9 (2.2) mm Hg, mean pulmonary artery pressure 67.4 (3.0) mm Hg, cardiac index 1.75 (0.13) l/min/m 2 and mixed venous oxygen saturation 59.1(3.1)%. Continuous intravenous epoprostenol (prostacyclin, PGI 2 ) or iloprost was given for phase I (three to six weeks); the patients were then crossed over to receive the alternate drug in an equivalent phase II. Main outcome measures Exercise tolerance was measured at baseline and at the end of phase I and II with a 12 minute walk; distance covered, rest period, percentage drop in arterial oxygen saturation (ΔSao 2 %) and percentage rise in heart rate (ΔHR%). Results Walking distance covered rose from (mean (SEM)) 407.5 (73) to 591 (46) m with PGI 2 (p = 0.004) and to 602.5 (60) m while on iloprost (p = 0.008). Rest period decreased from 192 (73) seconds at baseline to 16 (16) seconds with PGI 2 (p = 0.01) and to 58 (34) seconds with iloprost (p = 0.008). ΔHR% was 37.5(6)% at baseline, 35(3)% on PGI 2 , and 24(6)% on iloprost (p = 0.04). Conclusions Both intravenous PGI 2 and iloprost caused significant improvement in exercise tolerance. Iloprost offers an alternative to PGI 2 treatment of severe pulmonary hypertension.

Clinical and morphological characteristics in Streptococcus bovis endocarditis: a comparison with other causative microorganisms in 177 cases

Abstract: Aim—To compare the clinical and morphological characteristics of patients with Streptococcus bovis endocarditis with those of patients with endocarditis caused by other microorganisms. Methods—177 consecutive patients (Streptococcus bovis, 22; other streptococci, 94; staphylococci, 44; other, 17) with definite infective endocarditis according to the Duke criteria were included. All patients underwent transthoracic and transoesophageal echocardiography. In 88 patients, findings from surgery/necropsy were obtained. Results—S bovis endocarditis was associated with older patients, with a higher mortality (p = 0.04), and with a higher rate of cardiac surgery (p < 0.001) than other microorganisms, although embolic events were observed less often (p = 0.02). Pathological gastrointestinal lesions were detected in 45% of the patients. Multiple valves were affected in 68% of the patients with S bovis endocarditis and in 20% of those with other organisms (p < 0.001). Moderate or severe regurgitation occurred more often in S bovis endocarditis than with other microorganisms (p = 0.05). When surgery or necropsy was performed, infectious myocardial infiltration of the left ventricle was confirmed histopathologically in 36% of the patients with S bovis endocarditis and in 10% of those with other organisms (p = 0.002). Conclusions—S bovis endocarditis is a severe illness because of the more common involvement of multiple valves, and of the frequent occurrence of haemodynamically relevant valvar regurgitation and infectious myocardial infiltration. Keywords: infective endocarditis; Streptococcus bovis; transoesophageal echocardiography; valvar disease

Aneurysms and pseudoaneurysms of saphenous vein coronary artery bypass grafts

Abstract: Aneurysms of saphenous vein grafts to coronary arteries are unusual complications of coronary artery bypass graft (CABG) surgery. Three patients (men aged 47, 62, and 68 years) are presented with spontaneous chest pains 10, 21, and 17 years after CABG surgery. In one case, the saphenous vein graft had eroded into the right atrium and had established a fistula between the graft and the right atrium. Diagnosis of saphenous vein graft aneurysms was confirmed by echocardiography, computed tomography or magnetic resonance imaging, and by arteriography. Two patients were treated surgically, the third by percutaneous coil embolisation followed by balloon angioplasty of the right coronary artery.

Comparison of peripheral endothelial dysfunction and intimal media thickness in patients with suspected coronary artery disease

Abstract: Objective Flow associated dilatation (FAD%) and intimal media thickness are established markers of early atherosclerosis. This study aimed to compare the ability of the non-invasive measurements FAD% and intimal media thickness to predict coronary artery disease. Methods FAD% and intimal media thickness were determined using high resolution ultrasound in 122 patients with clinically suspected coronary artery disease before coronary angiography. Results are given as mean (SD). Results Patients with coronary artery disease had reduced FAD% compared with those with angiographically normal coronary vessels (3.7 (4.1) v 7.0 (3.5)%, p v 0.47 (0.11)mm, p = 0.054). There was a negative correlation between FAD% and intimal media thickness ( R = −0.317, p = 0.0004). Receiver operating characteristic analysis showed that FAD% ⩽ 4.5% predicted coronary artery disease with a sensitivity of 0.71 (95% confidence interval 0.61 to 0.80) and a specificity of 0.81 (0.58 to 0.95). In contrast, intimal media thickness showed a positive correlation with the extent of coronary artery disease (number of vessels with a lesion ⩾ 50%) ( R = 0.324, p = 0.0003), without a clear cut off point. Conclusions In patients with clinically suspected coronary artery disease, FAD% discriminates between the presence or absence of coronary artery disease, whereas intimal media thickness is associated more with the extent of coronary artery disease.

von Willebrand factor, tissue plasminogen activator, and dehydroepiandrosterone sulphate predict cardiovascular death in a 10 year follow up of survivors of acute myocardial infarction

Abstract: Background—Haemostasis plays a major part in the process initiating a myocardial infarction. The impact of haemostatic variables on long term prognosis is unknown. Objective—To evaluate von Willebrand factor (vWF), tissue plasminogen activator antigen (t-PA) and its activity before and after venous occlusion, plasminogen activator inhibitor (PAI-1), dehydroepiandrosterone sulphate (DHEAS), and established clinical risk factors as long term predictors for reinfarction and mortality. Patients—123 consecutive survivors of myocardial infarction followed up for 10 years. Design—Study entry took place between 1982 and 1983. Fifty seven patients died (54 of cardiovascular disease) during the mean observation time of 10 years. Results—Cox's univariate regression analysis showed that cardiovascular mortality was significantly associated with age, hypertension, previous history of angina pectoris, DHEAS, mass concentration of t-PA, and vWF. These associations were significant for vWF and mass concentration of t-PA after adjusting for age and hypertension. Conclusions—A low concentration of DHEAS and high levels of the endothelially derived haemostatic variables vWF and mass concentration of t-PA are predictors of cardiovascular mortality in survivors of myocardial infarction. This association is independent of established clinical risk factors for mass concentration of t-PA and vWF. Keywords: myocardial infarction; risk factors; fibrinolysis; tissue plasminogen activator; plasminogen activator inhibitor; von Willebrand factor; dehydroepiandrosterone sulphate