Showing papers in "European Heart Journal in 1987"

Spontaneous course of aortic valve disease

Abstract: The fate of patients with aortic valve disease of varying degrees of severity and the relationship between symptoms and haemodynamic status have been studied in 190 adults undergoing cardiac catheterization during the last two decades. During the follow-up period, 41 patients died and 86 underwent aortic valve replacement; these two events were the endpoints for the calculation of 'event-free' cumulative survival. First-year survival in haemodynamically severe disease was 60% in aortic stenosis and 96% in aortic regurgitation; in moderate and mild disease (in the absence of coronary artery disease) first-year survival was 100% in both groups. After 10 years, 9% of those with haemodynamically severe aortic stenosis and 17% of those with severe regurgitation were event-free, in contrast to 35% and 22%, respectively, of those with moderate changes and 85% and 75%, respectively, of those with mild abnormalities. In the presence of haemodynamically severe disease, 66% of the patients with stenosis and 14% of those with regurgitation were severely symptomatic (history of heart failure, syncope or New York Heart Association class III and IV); 23% of patients with moderate stenosis and 14% with moderate regurgitation were also severely symptomatic. Only 40% of those with disease that was severe both haemodynamically and symptomatically with either stenosis or regurgitation survived the first two years; only 12% in the stenosis group and none in the regurgitation group were event-free at 5 years. Patients with haemodynamically severe aortic stenosis who had few or no symptoms had a 100% survival at 2 years; the comparable figure for the aortic regurgitation group was 94%; 75% of the patients in the stenosis group and 65% in the regurgitation group were event-free at 5 years. In the moderate or mild stenosis and regurgitation groups there was no mortality within the first 2 years in the absence of coronary artery disease, regardless of symptomatic status. Haemodynamically and symptomatically severe aortic stenosis and regurgitation have a very poor prognosis and require immediate valve surgery. Asymptomatic and mildly symptomatic patients with haemodynamically severe aortic stenosis are at low risk and surgical treatment can be postponed until marked symptoms appear without a significant risk of sudden death. In severe aortic regurgitation, the decision for surgery should depend not only on symptoms but should be considered in patients with few or no symptoms because of risk of sudden death. In the absence of coronary artery disease, moderate aortic valve disease does not require valve operation for prognostic reasons.

Value, sensitivity and specificity of stroke volume ratio in routine equilibrium gated scintigraphy.

Abstract: The stroke volume ratio (SVR) is a new, non invasive method to quantify ventricular volume overload (VVO). We have analyzed its value, sensitivity and specificity in routine clinical practice. The results of 238 consecutive patients (pts) were analysed prospectively within a 3 months period. The SVR was expressed as the ratio of left ventricular (LV) stroke counts over the right ventricular (RV) stroke counts measured on the time-activity curves. One region of interest was drawn per ventricle on the phase and amplitude images. Values above 1.6 were considered as LVVO and below 0.9 as RVVO. Fifty-one patients had VVO due to valvular regurgitation or left-to-right shunt; 187 patients had no evidence of VVO. Mean value obtained for 23 normal subjects with adequate positioning was 1.27 +/- 0.14 (MV +/- SD), ranging from 0.9 to 1.47. Among patients with adequate positioning, no difference was observed in subgroups with dilated cardiopathy (DC) or anteroseptal aneurysm (AA) despite a low EF. MV for patients with LV or RV hypertrophy (H) were statistically different. Sensitivity was 82% for the 51 patients with VVO. False negatives were due to biventricular overload or mild VVO. Specificity evaluated in the 187 patients without VVO was 76%. The 45 false positives were due to poor separation of the right cardiac chambers and/or of the 2 ventricles. They were observed in 4 patients with AA, 3 patients with DC, 7 patients with LVH, 4 patients with RVH and 24 patients with inadequate positioning. No explanation was found in 3 patients. We conclude that cardiac equilibrium blood pool scintigraphy has an adequate sensitivity and specificity to evaluate patients with VVO.

Obesity and hypertension: Epidemiological and clinical issues

Abstract: The relationship between obesity and hypertension has been investigated in a large number of cross-sectional population studies and a smaller number of prospective, observational studies. The results indicate that in most populations, blood pressure increases linearly with increasing body weight or body mass index. The relationship is present across all subgroups, although the magnitude of the association appears greater in whites than blacks and greater in younger than older persons. It is estimated that as much as one-third of all hypertension may be attributable to obesity in populations where hypertension and obesity are widely prevalent. Evidence from prospective studies and clinical trials suggests that hypertension in obese patients increases the risk of cardiovascular disease and that drug treatment of hypertension reduces the risk. However, it is uncertain whether the risks associated with hypertension and the benefits of treatment are as great in obese hypertensives as they are in lean hypertensives. The effects of weight reduction on blood pressure have been investigated in a small number of randomized, controlled trials involving a total of about 600 participants. Overall, the results of the trials indicate that weight reduction lowers blood pressure over intervals of up to one year. The magnitude of the blood pressure response appears to be directly proportional to the amount of weight loss achieved. However, the latter is inversely related to the length of follow-up. Adequate maintenance of weight loss remains a major problem for the much-needed, long-term trials of the effects of weight reduction on blood pressure and the cardiovascular complications of hypertension.

Chronic atrial fibrillation--epidemiologic features and 14 year follow-up: a case control study.

Abstract: In a randomly selected population of 9067 individuals, 32–64 years of age in 1967–1970, 25 (0.28%) had chronic atrial fibrillation (CAF). Eight had lone atrial fibrillation. In 1984 the cases were compared with an age- and sex-matched control group of 50 and found to have more cerebrovascular accidents (6 versus 2; P < 0.05), congestive heart failure (9 versus 1; P < 0.001), and valvular rheumatic heart disease (3 versus 0) or history consistent with rheumatic fever (6 versus 0; P < 0.01). The mortality in the CAF group was 60% higher due to an excess in cardiovascular (relative risk 6.1; P<0.05) and cerebrovascular (relative risk 12.2; P<0.05) causes. The prevalence or incidence of ischaemic or hypertensive heart disease or the presence of coronary risk factors did not significantly differ in the two groups. By M-mode echocardiography the left atrial size, left ventricular enddiastolic dimension and left ventricular mass were increased in the CAF patients, while the systolic left ventricular shortening was significantly less. Thus, the prevalence of CAF is low in a randomly selected population 32–64 years of age and CAF is not strongly associated with ischaemic heart disease or hypertension. The CAF patients have an increased risk of dying prematurely particularly from cerebrovascular causes, even in the absence of valve disease.

Cardiac and pulmonary causes of dyspnoea--validation of a scoring test for clinical-epidemiological use: the Study of Men Born in 1913.

Abstract: Dyspnoea is one of the earliest symptoms in several conditions, such as heart disease and airway obstruction. However, the early phases of these two conditions are hard to distinguish in a reproducible way. In a population study of the natural history and epidemiology of congestive heart failure a scoring test to differentiate the two conditions was developed. In this report the test is presented and evaluated against various clinical and laboratory measures in 644 men sampled from the general population. The test provides a ‘cardiac score’ and a ‘pulmonary score’, both based on history and findings at the physical examination. Men who had pulmonary scores (indicating a pulmonary cause of the dyspnoea) had significantly lower values of spirometry variables but no significant pulmonary congestion at X-ray compared to a reference group (no dyspnoea, no pulmonary scores). Men with cardiac scores had significantly larger hearts and more congestion but no significant change of variables measuring airways obstruction compared to the reference group (no dyspnoea, no cardiac scores). Even though there was a moderate overlap of impaired cardiac and pulmonary function in the dyspnoea group, perhaps due to smoking being a common causal agent, the test appears to differentiate the causes of dyspnoea in a manner similar to clinical evaluation but, in contrast to the latter, in a defined and therefore reproducible way.

Epidemiology and prevention of cardiac failure: Framingham Study insights.

Abstract: The prevalence, incidence, secular trends, precursors and prognosis of cardiac failure (CHF) is investigated over 3 decades of follow-up of 5209 subjects Some 485 men and women developed first evidence of CHF Annual incidence increased from 3 per 1000 at ages 35-64 years to 10 per 1000 at ages 65-94 years with a male predominance because of higher rates of coronary disease Half developing CHF had coronary disease, but only 10% were free of concomitant hypertension Appearance of coronary disease conferred an 8-fold increased risk of CHF Hypertension is the dominant precursor of CHF, increasing risk 2-6 fold; 70% had antecedent hypertension Systolic pressure was more predictive than diastolic Non-specific S-T and T-wave changes, intraventricular conduction disturbances and left ventricular hypertrophy were powerful predictors, even taking blood pressure into account Other independent risk factors include: low vital capacity, rapid heart rate, diabetes, cardiac enlargement, overweight (in women), serum cholesterol (in men under 65 years of age), cigarettes, proteinuria and hematocrit Risk of CHF can be estimated over a 30-fold range from profiles made up of these independent risk factors A preventive approach is essential Despite potent glycosides, diuretics, vasodilators and antihypertensive treatment CHF continues to be a lethal end-stage of heart disease with a 50% 5 year mortality rate Sudden death is a prominent terminal feature occurring at 9 times the general population rate

Prediction of cardiac risk in non-cardiac surgery

Abstract: This prospective study was carried out to develop a model for the prediction of cardiac risk in non-cardiac surgery. Detailed data were collected concerning the preoperative status of 2609 consecutive patients, who were followed closely during the postoperative course. Fatal or life-threatening cardiac complications occurred in 68 patients (2.6%). By utilizing logistic regression, a model for prediction of cardiac risk was developed. The model contained six significant preoperative predictor variables: Congestive heart failure (with 3 degrees of severity); ischaemic heart disease (with 2 degrees of severity); diabetes mellitus; serumcreatinine above 013 mmol l−lemergency operation; and the type of operation (two categories) With this model it seems possible to discriminate between patients with very different levels of cardiac risk.

Coarctation of the aorta : review of 362 operated patients. Long-term follow-up and assessment of prognostic variables

Abstract: 362 patients operated upon for coarctation of the aorta from 1961–1980 were analyzed retrospectively Age at operation was <2 years in 74 (group A ) and ≧2 years in 288 patients (group B) Associated cardiovascular malformations were common, especially in group A patients Early mortality was 12-2% for group A and 1-4% for group B patients 336 patients were followed for 6 months to 21 years (mean 89 years) Late mortality was 08% per patient year Associated cardiac defects and postoperative hypertension were responsible for most of the late deaths Late reoperations were performed because of aortic valve disease, residual coarctation (with persistent hypertension) and aortic aneurysms at the site of anastomosis The incidence of hypertension decreased from 825% preoperatively to 335% at discharge from the hospital It decreased further during follow-up in patients operated <10 years of age, but remained constant in the older patients In conclusion, morbidity and mortality after operative repair of coarctation are determined mainly by (1) associated cardiac malformations, and (2) postoperative hypertension Patients with isolated coarctation and postoperative normal blood pressure have an excellent prognosis Patients operated upon from between 2–9 years of age carry the lowest risk for residual coarctation and late postoperative hypertension

Left bundle branch block: prevalence, incidence, follow-up and outcome

Abstract: In a randomly selected population screening study of 8450 men and 9039 women 33 to 71 years of age conducted in Iceland in 1967-1977, 27 men and 17 women were found to have left bundle branch bock (LBBB). The prevalence of LBBB at that time was 0.43% for men and 0.28% for women. The incidence of LBBB was 3.2 per 10,000 per year for men and 3.7 per 10,000 per year for women. All except one of 37 alive patients with LBBB were examined in 1984 including chest X-ray, echocardiography and exercise testing (Bruce protocol). Eight men had had myocardial infarction (P less than 0.05), 12 had angina pectoris, 15 had hypertension, 7 had cardiomyopathy, 13 had primary conduction disease, and 3 had pacemakers. Five men and two women had died in comparison with 18 men and 1 woman in an age-matched control group of 176 people (P : ns). Three of 5 decreased LBBB men had cardiomyopathy at autopsy. Three men died suddenly. The two women died of noncardiac causes. Only one patient in the control group had cardiomyopathy (P less than 0.01). There was no significant difference in other cardiac diagnoses between the groups. Eleven LBBB women out of thirteen had a normal exercise duration (greater than or equal to 6 min) and 11/17 men exercised normally (less than or equal to 7 min). In comparison with the control group, the LBBB patients had an increased LV diameter 2.85 +/- 0.38 vs 2.58 +/- 0.38 cm m-2 body surface area (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Release and regulation of atrial natriuretic peptide (ANP)

Abstract: Mammalian atrial cardiocytes synthesize and secrete a hormone called atrial natriuretic peptide (ANP), which causes natriuresis, diuresis and inhibition of smooth muscle contraction, aldosterone and renin release. Volume loading, vasoconstrictor agents, immersion in water, atrial tachycardia and high salt diets have been reported to increase the release of cardiac ANP, thereby suggesting that the peptide is released in response to an increase in atrial pressure. That stretch is an important stimulus for ANP release is also suggested by clinical studies demonstrating a direct correlation between secretion rate and atrial pressure. The experiments using isolated perfused rat heart provide direct evidence that distension of the right atrium stimulates the release of ANP. Pharmacological studies in the isolated heart point to roles of cytosolic calcium, the phosphoinositide system and the cyclic AMP pathway in the regulation of ANP release. The concentration of calcium in heart muscle cells, in addition to the length of the muscle fibers, depends on many factors such as the action of humoral substances, cardiac nerve activity and heart rate, which may all contribute to the regulation of ANP secretion.

Randomized factorial trial of high-dose intravenous streptokinase, of oral aspirin and of intravenous heparin in acute myocardial infarction

Abstract: 619 patients with suspected acute myocardial infarction (MI) were randomized to receive either a high-dose short-term intravenous infusion of streptokinase (1.5 MU over one hour) or placebo. Using a '2 × 2 × 2 factorial' design, patients were also randomized to receive either oral aspirin (325 mg on alternate days for 28 days) or placebo and separately randomized to receive either intravenous heparin (1000 1U h-1 for 48 hours) or no heparin. Streptokinase (SK) was associated with a nonsignificant (NS) increase in non-fatal reinfarc–tion (3.9% SKvs 2.9% placebo) and decrease in mortality (7.5%vs9.7% in hospital plus 6.1%vs 8.7% after discharge). After SK, there were significantly fewer strokes (0.5% vs 2.4%; 2P<0.05), but significantly more minor adverse events (e.g. hypotension and bradycardial, allergies, bruises or minor bleeds, nausea). Aspirin was associated with fewer non-fatal reinfarctions (3.2% aspirin vs 39% placebo; NS), deaths (in hospital: 61% vs 10.5%; 2P<0.05, and after discharge: 7.0% vs 6.9%; NS), and strokes (0.3% vs 2.0%; NS). Heparin was associated with a decrease in reinfarction (2.2% heparin vs 4.9% no heparin; NS), though not in mortality (in hospital: 8.0% vs 8.5%; NS, and after discharge: 7.0% vs 6.9%; NS), and with a trend towards more strokes (1.6% vs 0.7%; NS) and more bruising and bleeding (14% vs 12%; NS). To assess more reliability the effects of aspirin and of this SK regimen on mortality, about 400 hospitals worldwide are now collaborating in a large (about 20 000 patients planned ) randomized trial ( ISIS-2). for which the present study was a pilot.

5-year results of a comprehensive rehabilitation programme after myocardial infarction.

Abstract: A comprehensive cardiac rehabilitation programme has been offered to a non-selected consecutive group of patients who have survived an acute myocardial infarction (MI). The programme includes follow-up at a post-MI clinic, physical training in outpatient groups, the provision of information on smoking and diet, and psychological support to patients and their families. The intervention group, consisting of the 147 patients participating in the programme has been compared with a nonselected consecutive reference group of 158 patients receiving standard care. During the five-year follow-up there was no difference in cardiac mortality between the groups, but the recurrence rate of non-fatal Ml (17.3 vs 33.3%. P = 0.02) and the rate of total cardiac events was lower in the intervention group (39.5 vs 53.2%, P = 0.05). There was an alteration of risk factors, as there were fewer smokers and uncontrolled hypertensives in the intervention group. Patients in the reference group used more sedatives and long-acting nitroglycerine ami had a lower return-to-work rate during the study period. The programme proved to be particularly effective in the age group below 55 years, where a significantly lower rate of total cardiac events was observed and more patients returned to work than in the reference group. It is concluded that the combined effect of the comprehensive programme has contributed to the long-term results, and that the programme offers an effective and safe method of secondary prevention after MI.

Long-term follow-up of acute myocarditis. Correlation of ventricular function and outcome

Abstract: Clinical, echocardiographic, haemodynamic and histological evaluation was performed at initial presentation and at 2, 6 and 12–24 monthly intervals in 23 patients with biopsy-proven acute myocarditis (ACM). Late (4–5 years) follow-up in survivors included radionuclide assessment of left ventricular function during exercise. Left ventricular ejection fraction (EF) was severely impaired in 81% of patients (EF 31 ± 4.4%; mean ± SEM). After 6–8 months follow-up two groups had emerged. Group 1: normal (EF 62 ± 1.9%; N = 9); group 2: impaired left ventricular function (EF 29 ± 4.7%; N = 8), P < 0.001. Group 1 patients remained clinically normal at long-term follow-up. Histological findings indicative of dilated cardiomyopathy were found in seven patients in group 2. At late follow-up, 7–9 patients who were clinically normal had abnormal EF response to exercise (rest 68 ± 2.8% /exercise 62 ± 3.4%; P < 0.02). Altogether, characteristic features of dilated cardiomyopathy developed in 12 patients (52% ), four of whom died. Assessment of left ventricular function 6–8 months following acute myocarditis predicts outcome. Late follow-up has shown progression to dilated cardiomyopathy in 50%, and most have persistent impairment of cardiac reserve.

Contribution for choosing the optimal prophylaxis of bacterial endocarditis

Abstract: The beneficial effect of endocarditis prophylaxis was studied in 229 patients with prosthetic heart valves, in whom 287 diagnostic interventions were performed. The prevention used was similar to that recommended earlier by the American Heart Association. Prosthetic valve endocarditis was not observed in any of these patients. This result was compared with that of 304 patients with prosthetic heart valves, in whom, without any prevention, 390 similar interventions were performed during the same observation period. The incidence of prosthetic valve endocarditis occurring within 14 days after the intervention was 1 .5/100 interventions (N = 6). All patients required re-operation. One patient died peri-operatively. Two more patients developed prosthetic valve endocarditis 8 and 13 weeks, respectively, after the initial intervention. This retrospective study documents the benefit of the endocarditis prophylaxis used.

Early intervention with nimodipine in subarachnoid haemorrhage

Abstract: Seventy-five consecutive patients with subarachnoid haemorrhage (SAH) were entered into a randomized, double-blind, placebo-controlled trial prior to angiography in order to determine the effect of early intervention with nimodipine on blood pressure (BP), cerebral blood flow (CBF), and clinical outcome. Of these patients, 50 fulfilled the criteria for the final analysis (i.e. SAH due to cerebral aneurysm and receiving 21 days of treatment). There was no difference between the BP recordings of the two treatment groups, but mean CBF decreased slightly in the nimodipine group over the 21-day treatment period. At three months, one patient on nimodipine and six patients receiving placebo had died (P = 0.049, Fisher's exact test), but no significant difference was observed between the two groups, when the ‘intent to treat’ group of 75 patients was considered. We conclude that nimodipine does not increase CBF or alter BP following SAH, but an improved clinical outcome is evident at three months for patients with SAH due to cerebral aneurysm who had been treated with nimodipine. There were no side-effects due to nimodipine.

Effect of continued rt-PA administration on the residual stenosis after initially successful recanalization in acute myocardial infarction – a quantitative coronary angiography study of a randomized trial

Abstract: Quantitative angiography was performed in 68 out of 123 patients treated with intravenous rt-PA for acute myocardial infarction. At 90 min angiography, the median minimal cross-sectional area was 1.11 mm2 and the median percentage area stenosis was 80%. A percentage area stenosis greater than 70% was seen in 78% of the patients. Patients with a patent infarct related artery at the first angiogram were randomized to receive subsequent infusions either of rt-PA + heparin or placebo + heparin. There was a persistent trend of improvement in minimal lumen diameter and percentage diameter stenosis of the residual stenosis in the infarct related artery in both treatment groups when re-examined 6–24 hours later and at the time of hospital discharge. A reduction in ‘plaque area’, the area between the detected and the reference contours of the infarct related segment, was more frequently seen in patients receiving a second infusion of rt-PA than in patients with no prolonged thrombolytic therapy (83% versus 57%, P<0.025, chi square).

Influence of regular physical activity on blood rheology

Abstract: Blood rheology is one of the determinants of blood flow which becomes important when vasomotor reserve is limited or exhausted. It can be quantified ex vivo by measuring blood and plasma viscosity, haematocrit, red cell deformability and aggregation. To investigate the effects of regular exercise, a number of different experimental approaches were undertaken. A cross-sectional comparison of male athletes with sedentary matched controls showed that blood and plasma viscosity were lower and red cell deformability better in sportsmen. A 3-month longitudinal study of initially untrained healthy volunteers performing regular training revealed a fall of blood viscosity and an amelioration of red cell deformability. Finally a 2-month trial submitting claudicants to regular treadmill exercise showed a progressive fall in blood and plasma viscosity and a rise in red cell deformability. This suggests that an improvement in blood fluidity can be induced by regular physical exercise regardless of whether the blood rheology was normal or abnormal at baseline. The relevance of these findings could be three-fold. Firstly the "better than normal" blood rheology in athletes may contribute to enhanced blood flow in the working musculature and thus increase work output. Secondly the data supports the thesis of a link between blood rheology and atherogenesis. Thirdly regular exercise might be a way of therapeutically increasing blood flow in ischaemic vascular diseases.

Reduction of exercise tachycardia in man after propranolol, atenolol and bisoprolol in comparison to beta-adrenoceptor occupancy

Abstract: In a double blind, placebo controlled study, propranolol (240 mg), atenolol (200 mg) or bisoprolol (100 mg) were administered as a single oral dose to groups of 6 healthy male volunteers. Exercise tachycardia was monitored for 84 hours after administration of the drugs to monitor beta blockade in vivo. Plasma samples drawn in parallel with these effects were used to detect beta 1- or beta 2-adrenoceptor occupancy in two subtype selective in vitro receptor binding assays. Reduction of exercise tachycardia parallels beta 1-adrenoceptor occupancy. Furthermore, at comparable beta 1-adrenoceptor occupancy, less beta 2-adrenoceptor occupancy was observed after bisoprolol than after atenolol. The latter finding is in agreement with the two-fold higher beta 1/beta 2-selectivity ratio of bisoprolol (75-fold) versus atenolol (35-fold). It is concluded, that beta blockade observed via the reduction of exercise tachycardia can be delineated from the in vitro occupancy of beta 1-adrenoceptors by an antagonist present in plasma samples.

The Lopressor Intervention Trial: Multicentre study of metoprolol in survivors of acute myocardial infarction

Abstract: The Lopressor Intervention Trial (LIT) was a double-blind, randomized, placebo-controlled, multicentre study designed to evaluate the effect of oral metoprolol on overall mortality in patients surviving a recent acute myocardial infarction. Patient enrollment began in August 1979 and ended on 15 April 1982, with 2395 patients (1200 on placebo and 1195 on metoprolol). Hospitalized patients, 45 to 74 years of age, began therapy from 6 to 16 days after their myocardial infarction. Following a short titration period, maintenance therapy with metoprolol 100 mg b.i.d. or placebo was continued for up to 1 year. Enrollment was prematurely terminated because of a progressive and marked decline in patient accession; it was not feasible to reach the original goal of 3200 patients in a practical period of time. This target sample size was based on an anticipated 1 year placebo mortality rate of 10%, a 50% reduction in total mortality with metoprolol and premature discontinuation of study medication in no more than 15% of patients in the metoprolol group. Two primary analyses were planned: total mortality among all randomized patients at 7 and at 12 months of trial entry. After 7 months of treatment there were 54 deaths in the placebo group and 42 deaths in the metoprolol group. After 1 year there were 62 deaths in the placebo group and 65 in the metoprolol group. Thus, the 1 year placebo mortality rate of 5.2% was half that predicted at the outset. In addition, study medication was prematurely discontinued in over 30% of patients in the metoprolol group.(ABSTRACT TRUNCATED AT 250 WORDS)

Fundamental differences between the standard 12-lead electrocardiograph and the modified (Mason-Likar) exercise lead system.

Abstract: A comparison of the standard 12-lead electrocardiograph with the Mason-Likar lead system widely used for exercise stress testing shows that the two are not 'essentially identical' as was originally claimed. Placement of the limb electrodes onto the torso distorts the electrocardiograph causing a rightward shift of the mean QRS axis, a significant reduction in R-wave amplitude in leads I and aVL, and a significant increase in R-wave amplitude in leads II, III and aVF; the R-wave amplitude of the chest leads is also altered. The so-called 'inferior' leads on the exercise electrocardiography are probably modified anterior/inferior leads, since their R-wave amplitudes correlate closely with those of antero-lateral chest leads. The inferior surface of the heart is not represented in isolation on the exercise electrocardiograph, thus explaining the reported inability of the exercise test to predict the location of coronary artery disease and high incidence of false negative tests in patients with ischaemia limited to the inferior cardiac surface.

Comparison of pharmacokinetic properties of beta-adrenoceptor blocking drugs

Abstract: Beta-adrenoceptor blocking drugs can be characterised by their pharmacokinetic properties. One of the most important factors appears to be lipid solubility. Lipophilic beta-adrenoceptor antagonists, such as propranolol, oxprenolol and metoprolol, are cleared by the liver and undergo hepatic 'first-pass' metabolism. This results in low bioavailability, substantial interpatient variability in 'steady-state' plasma drug concentrations, rapid elimination half-lives and the possibility of drug interactions with other drugs such as pentobarbitone and cimetidine which affect hepatic enzymes. In addition, lipid soluble drugs are distributed widely within the body and penetrate the brain easily and rapidly. This may result in centrally mediated adverse effects such as vivid dreams. In contrast, the more water-soluble beta-adrenoceptor blocking drugs, such as atenolol, sotalol and nadolol, are cleared by the kidney unchanged. They show less interpatient variation in plasma levels, have longer elimination half-lives and do not interact with drugs affecting hepatic enzymes. They penetrate the central nervous system less easily and cause less central side-effect. Between these two extremes, there are several drugs like betaxolol, bisoprolol and pindolol, which are cleared partly by the liver and partly by the kidney. Their clearance is only altered by severe renal or hepatic disease, and they do not appear to interact with enzyme inducers or inhibitors.

The effects of beta-adrenergic blocking agents on atherosclerosis and its complications.

Abstract: Epidemiologic and experimental data are reviewed to determine whether treatment with beta-adrenergic blocking agents (‘beta blockers’) is likely to be antiatherogenic. Both indirect and direct evidence are considered. Indirect evidence is derived from studies of the effects of beta blockers on the risk factors for atherosclerosis, or on the disease sequelae of atherosclerosis. Direct evidence refers to studies in which atherosclerosis is an endpoint. Regarding indirect evidence, the data generally are consistent with a retarding or neutral effect of beta blockers on atherosclerosis. For example stroke incidence is reduced when hypertension is treated with beta blockers. About half of these same studies also show a reduction in the incidence of myocardial infarction, a complication that may be more closely related to atherosclerosis extent and severity than is stroke, which can have a nonatherosclerosis origin. The most important potential negative effect of beta blockers occurs with respect to serum lipid concentrations. However, there is no evidence that atherosclerosis is worsened as a result of pharmacologically induced alterations of serum lipids. The direct evidence more clearly indicates a retarding effect of beta blockers on atherosclerosis, with 11 of 13 studies having outcomes in this direction. However, interpretation of these studies is complicated by the fact that all of the data are derived from animal models, some of which are not similar to human beings in the development of atherosclerosis. Also, the studies are diverse, not only in the research designs and species utilized, but also in the type of beta blocker employed, the degree of beta blockade acheived, and the anatomic location of lesions. In summary. the data suggest that treatment with beta blockers may retard atherosclerosis. A more definitive answer requires efforts in two directions: (a) studies on atherosclerosis in selected populations of human beings, using cineangiography or autopsy material; and (b) additional, well-controlled studies in appropriate animal models.

The management of clinical arrhythmias. An overview on invasive versus non-invasive electrophysiology

Abstract: Chacun appelle idees claires celles qui sont au me me degre de confusion que les stennes propres.(Everyone labels as clear those ideas that are as confused as his own.)

Cardiac events after myocardial infarction: Possible effect of relaxation therapy

Abstract: Comprehensive cardiac rehabilitation aims primarily at improving quality of life, but an effect on morbidity and mortality may also be expected, especially when changes in behaviour and life-style are induced. The value of relaxation therapy and exercise training in post myocardial infarction (M1) patients was investigated. A group of 90 post M1 patients were randomly assigned to either exercise training plus individual relaxation and breathing therapy (treatment A), or exercise training only (treatment B). The occurrence of cardiac events, consisting of cardiac death and of readmission to hospital for unstable angina pectoris, coronary artery bypass grafting (CABG) or recurrent infarction, differed significantly for the two treatment groups in the 2–3 years after infarction. Seven out of 42 patients in treatment group A (17%) experienced a cardiac event, in contrast to 17 out of 46 (37%) patients in treatment group B, (P = 005, two-tailed). The results suggest that a combination of a behavioural treatment such as relaxation therapy with exercise training is more favourable for the long-term outcome after myocardial infarction than is exercise training alone.

Conventional and transoesophageal echocardiography in the diagnosis of infective endocarditis

Abstract: Echocardiography is commonly accepted as the method of choice for non-invasive assessment of vegetations and valve destruction in patients with infective endocarditis. The sensitivity of the technique for diagnosing endocarditis-induced lesions increases from about 60% to more than 70% when the two-dimensional transthorucic technique is used in addition to the M-mode approach; a detection rate higher than 90% can be obtained when transoesophageal imaging is used. In addition, transoesophageal echocardiography seems to be a most-valuable tool for the pre-operative assessment of endocarditis-associated abscesses.

The Helsinki Heart Study: basic design and randomization procedure.

Abstract: The Helsinki Heart Study is a coronary primary prevention trial in a group of middle aged men with lipid abnormalities. Its aim is to investigate the effects on the incidence of coronary heart disease of simultaneously lowering serum total and low density lipoprotein (LDL)-cholesterol and elevating high density lipoprotein (HDL)-cholesterol with gemfibrozil, over a period of 5 years. Participants were selected from a population of 23 531 men between 40 and 55 years of age. The mean serum total cholesterol among 18 966 screened subjects was 6.3 mmol l-1 (245 mg dl-1) and the mean HDL-cholesterol 1.3 mmol l-1 (50.3 mg dl-1). All subjects meeting the lipid acceptance criterion of non-HDL-cholesterol (i.e. total cholesterol minus HDL-cholesterol) greater than 5.2 mmol l-1 (200 mg dl-1) on two separate occasions two to three months apart, who were free from coronary heart disease or other major illness, were invited to participate. The total cholesterol level for the final 4081 study participants was 7.5 mmol l-1 (290 mg dl-1) and HDL-cholesterol was 1.23 mmol l-1 (47.6 mg dl-1). Mean systolic and diastolic blood pressures were 141.7 and 91.3 mmHg. About 15% of participants were hypertensive and 36% were smokers. A total of 2051 men were randomly allocated to receive gemfibrozil 600 mg twice daily and 2030 matching placebo capsules. A cholesterol-lowering diet was also prescribed for all participants. The randomized treatment groups were well balanced. Equal distribution of major risk factors was achieved in relevant sub-groups. This report describes the procedures involved in setting up the study, summarizes the baseline data obtained and reviews the success of the randomization procedure. Finally, it compares the design of this study with that of some other major preventive trials.

Isolated coronary ostial stenosis: observations on the pathology.

Abstract: A 54 year old woman with isolated stenosis of the left coronary ostium died following cardiac catheterisation and emergency coronary artery bypass surgery. Histological examination showed the ostial narrowing to be a local and discrete plaque of atherosclerosis. Like most reported cases this patient was a young woman whose disease pursued an aggressive course.

Detection of persistent coxsackie B virus RNA in dilated cardiomyopathy and myocarditis

Abstract: Using a virus-specific cDNA hybridisation probe we have detected coxsackie B virus RNA sequences in 14 of 27 endomyocardial biopsy specimens from patients with histopathological evidence of active or healed myocarditis or of dilated cardiomyopathy. No coxsackie B virus-specific sequences were detected in 11 myocardial biopsies in which a viral aetiology was unlikely and the histological diagnosis negative for myocarditis or dilated cardiomyopathy.

Functional morphology of the mammalian sinuatrial node

Abstract: The primary pacemaker area is located at the site with lowest percentage of myofilaments and the highest rate of diastolic depolarization in rabbit, guinea-pig, cat and pig. All investigated sinuatrial nodes contained large amounts, 45% or more, of collagen. There was, however, substantially more collagen in the sinuatrial nodes of the cat and the pig than in the rabbit and the guinea-pig. This had, however, no consequences for the sinuatrial conduction time and the regularity of the beat-to-beat cycle length in the different species, because the rabbit and cat had comparable sinuatrial conduction times, although their nodal collagen content was very different and the beat-to-beat cycle length showed a comparable variability in the different species. We conclude that extensive proliferation of collagen and fibroblasts does not necessarily impair intercellular coupling in the sinuatrial node.