Showing papers in "European Heart Journal in 1982"

Echocardiographic assessment of left ventricular hypertrophy.

Abstract: Although methodological problems still exist echocardiography provides the best available non-invasive method for assessing left ventricular hypertrophy (LVH). Indeed, with recent technical advances two-dimensional echocardiography may provide a method that is at hast as accurate as the older angiographic techniques which are the best available invasive techniques. Further, computerised analysis of M-mode echocardiograms provides data about left ventricular function which are not readily available from any other technique. Because echocardiography is non-invasive it is particularly suitable for long-term studies of LVH, serial assessment of the ventricular consequences of valve disease and valve replacement and the effects of therapy. In addition, echocardiographic assessment of the left ventricle may allow the most appropriate form of therapy to be chosen in patients with congestive heart failure. The concepts built up during the extensive study of left ventricular disorders by echocardiography will be relevant to newer techniques such as computerised roentgenographic and positron emission tomography and nuclear magnetic resonance when they are applied in the same situations.

Vasodilation induced by transcutaneous nerve stimulation in peripheral ischemia (Raynaud‘s phenomenon and diabetic polyneuropathy)

Abstract: In four patients with Raynaud's disease and in two with diabetic polyneuropathy, low-frequency transcutaneous nerve stimulation (TNS) of remote sites for 30–45 min caused a dramatic peripheral vasodilation in the cold limbs with a rise in skin temperature of 7–10 °C (from 22–24 to 31–34 °C) for periods of 4–8 h or more. This rise was associated with relief of ischemic pain. The vasodilation is widespread, affecting the skin of all extremities, with slight temperature elevations of 0.5–2 °C in the warm body parts. It also includes the cranial vessels, as judged from the induced migraine-like headaches in some patients. The responses were more easily elicited in sympathectomized patients and in diabetic polyneuropathy, presumably due to reduced vasoconstrictive tone. Placebo effects were ruled out. The vasodilatory effect and ischemic pain were not blocked by conventional doses of the specific opiate antagonist naloxone, suggesting different mechanisms for suppression of non-ischemic pain and vascular effects. TNS may be tried as an alternative treatment in certain patients with peripheral vascular insufficiency.

Transcutaneous electrical nerve stimulation in severe angina pectoris.

Abstract: The pain-relieving effect of transcutaneous electrical nerve stimulation (TENS) was studied in 10 male patients with angina pectoris of functional class III or IV. All patients had been stabilized on long-term maximal oral treatment for at least six months. The effects of the TENS treatment were measured by means of repeated bicycle ergometer tests. All patients had an increased working capacity (16–85%) and decreased ST depression and reduced recovery time during TENS. No adverse effects were observed.

Premature beats in healthy subjects 40-79 years of age.

Abstract: In order to determine the prevalence and complexity of premature beats (PBs) in an adult population without apparent heart disease, 260 healthy subjects 40–79 years of age had a 24 h ambulatory ECG recording performed. A total of 221 subjects (87%) had one or more atrial premature beats (APBs) in the 24 h period, which was statistically significantly more than the number of subjects (179 or 69%) with ventricular premature beats (VPBs). Only 19 subjects (7%) had no PBs. More than 200 VPBs/24 h were seen in only 5% of the subjects, and a similar percentage had more than 200 APBs/24 h. There was a statistically significant increase in the number of VPBs as well as APBs with an increase in age. Multiform VPBs, VPB pairs, multiform APBs and atrial tachycardia (AT) were ‘normal’findings (seen in more than 5% of the subjects), whereas > 2 different VPB configurations, > 2 episodes of VPB pairs, ventricular bigeminy, R-on-T VPBs, ventricular tachycardia, > 2 episodes of AT and AT with more than 10 beats per episode were ‘abnormal’ findings (seen in less than 5% of the subjects). The number of VPBs was almost identical in two 24 h ECG recordings obtained at a mean interval of 22 months in 17 out of 22 subjects studied. Only two out of 22 had a significant change in the number of VPBs/24 h over the 22 month period. As a ‘normal’ range for the number of APBs as well as VPBs per 24 h a figure of 200 is proposed, and it is concluded that most complex types of PBs may occur as incidental findings in healthy adult subjects, but usually in small numbers.

Comparison of single-plane and biplane volume determination by two-dimensional echocardiography 1. Asymmetric model hearts

Abstract: In asymmetric model hearts volume was estimated by two-dimensional echocardiography (2-dE) and radiography, and the results compared to directly measured volume in the range from 10 to 320 ml (n = 22). The disc method, and the area-length and ellipsoid methods were used for both single-plane and biplane calculations. When biplane 2-dE measurements were calculated by the disc method and compared with directly measured volumes the regression equation was acceptably linear. For single-plane calculations, no linearity was found. For the disc method, the regression equation was given by y = 0.91x + 8.4, the correlation coefficient (r) was 0.989, and the standard error of estimate (s.e.e.) was ± 12.8 ml. The confidence interval was 0.85 to 0.98. With the area-length method the regression equation was y = 0.93x + 7.4, r = 0.987, s.e.e. = ± 14.0 ml. For the ellipsoid method, the regression equation was y = 0.89x + 1.2, r = 0.966, s.e.e. = ±22.0 ml. With radiographic biplane calculations compared to directly determined values the regression equation was also found to be linear. For single-plane calculations such linearity was not found. For the disc method the regression equation was y = 0.99x + 5.9, r = 0.991, and s.e.e. = ±12.6 ml. The confidence interval was 0.93 to 1.06. For the area-length method the regression equation was y = 1.01x + 9.0, r = 0.987, s.e.e. = ±15.0 ml, and for the ellipsoid method y = 0.97x − 3.3, r = 0.992, s.e.e. = ±11.2 ml. Thus, 2-dE is an accurate method for volume determination in asymmetric model hearts using biplane calculations and the disc method. Area-length and ellipsoid methods seemed to be less accurate. Compared to radiography, 2-dE yielded similar correlation coefficients and s.e.e.s. Whereas 2-dE slightly underestimated model heart volume (−4.5 ± 14.7 ml, NS), radiography overestimated the volume (+5.7 ± 12.3 ml, P <0.05). The mean difference between 2-dE and radiography was 10.2 ± 21.2 ml, P <0.05). These results ought to be taken into account when left ventricular volume determinations are done in patients with coronary artery disease.

Do endomyocardial biopsies represent the morphology of the rest of the myocardium?A quantitative light microscopic study of single v. multiple biopsies with the King's bioptome

Abstract: In this paper some possibilities have been explored for the contradictory reported results correlating morphological findings on tissue obtained by bioptome to haemodynamic and other clinical parameters. To illustrate the problem endomyocardial biopsies obtained from 79 patients, either from the right or left ventricle, have been analysed quantitatively. Emphasis was placed on the size of the biopsy, cell diameter and volume fraction of collagen as well as volume fraction of interstitium. The results have shown that great variability exists when comparing two biopsies from the same ventricle. The coefficient of variance regarding fibre diameter and volume fraction of interstitium was 18.6 and 28.9%, respectively, and amounts to 80.5% for the volume fraction of collagen. In addition, investigations as to whether or not the small tissue samples obtained by bioptome are representative of the rest of the myocardium, have been undertaken. For this purpose 23 hearts obtained at post-mortem have been analysed quantitatively, measuring the volume fraction of collagen. The results have shown that when five or more tissue samples have been obtained, quantitative representation of the interventricular septum (the rest of the myocardium?) is mirrored in the small tissue samples. It is, therefore, concluded that at least five biopsies are necessary to establish whether or not correlation between structural changes and the functional state of the heart exists. Unless this number of biopsies has been obtained, extreme caution in assessing prognosis must be exercised.

Reversal of left ventricular hypertrophy by antihypertensive therapy.

Abstract: The effect of antihypertensive therapy on left ventricular hypertrophy due to essential hypertension was determined echocardiographicallv in 27 previously untreated subjects with essential hypertension. Fifteen were treated with hydrochlorothiazide alone, while 12 received additional therapy with methyldopa to control blood pressure. After a mean treatment interval of 11 months, mean blood pressure had fallen from 167/109 to 138/94 mm Hg ( P < 0.001). Simultaneously, echocardiographic left ventricular posterior wall thickness fell from 11 to 10 cm ( P < 0.07) and septal thickness fell from 1.3 to 1.2 cm ( P < 0.05). End-diastolic relative wall thickness, an index of concentric hypertrophy, fell from 0.50 to 0.45 ( P < 0.01, normal mean value = 0.33 ± 0.06). Estimated endsystolic left ventricular wall stress was normal both before and after treatment. No significant differences were demonstrable between the two treatment subgroups. We conclude that, in asymptomatic essential hypertension, treatment with diuretic or diuretic plus methyldopa can result in nearly complete reversal of left ventricular hypertrophy, provided that good blood pressure control is obtained.

Coronary blood flow in left ventricular hypertrophy: a review of experimental data

Abstract: Ischemia is a potential complication of left ventricular hypertrophy (LVH). Under resting conditions, coronary blood flow (CBF) per unit mass and its transmural distribution are usually normal and reflect total or regional myocardial oxygen needs. Studies of the coronary circulation after stimulation by pharmacological means, pacing or excercise have revealed a wide spectrum of results from a normal increase in flow (coronary flow reserve) in some cases to a significant reduction in others with altered transmural distribution and decreased ratio of endo/epicardial flow. These results suggest that subendocardial ischemia may occur in experimental LVH. They are consistent with clinical observations of angina pectoris or ECG abnormalities in patients with LVH and no detectable coronary artery lesions. Much remains to be learned regarding changes in CBF with reversal of LVH. With regard to this problem, we found that the relation of myocardial mass to the driving head of pressure for the coronary circulation, i.e. the aortic pressure, plays a highly significant role. If aortic pressure and myocardial hypertrophy vary in parallel, little disturbance is expected in maximal coronary flow but if hypertrophy exists or persists in the presence of a relatively low aortic pressure, coronary reserve could be reduced. Thus, antihypertensive drugs that lower blood pressure but not LV mass may have adverse effects on the coronary flow reserve although blood pressure returns to normal.

The athlete's heart

Abstract: Cardiac hypertrophy due to athletic training is a normal physiological response. There is no evidence that such cardiac enlargement is in any way pathological, and generally the heart weight does not exceed the ‘critical heart weight’ of approximately 500 g, which seems to be the limit for physiological hypertrophy. Tkc cardiac enlargement that occurs in athletes ix often obvious on the chest X-ray and is frequently accompanied by a wide variety of ECG changes that may, on occasions, produce diagnostic difficulties. Although some authors, using echocardiography, have described different patterns of cardiac hypertrophy in athletes undertaking physical force and endurance events, our results do not bear this out. We found the greater degree of hypertrophy in endurance athletes, who show marked enlargement of left ventricular cavity dimensions and wall thickness. In contrast, physical force athletes, who often have enormous body mass, simply have an increase in heart size commensurate with their increase in body mass. Our studies in athletes who begin competition in childhood show that they may also develop an athlete's heart even before puberty. Long-term studies of such children, following them into adolescence, suggests that the end result of such training is a heart size similar to athletes who begin training after childhood. Therefore, there is no evidence that children can develop cardiac hyperplasia as well as hypertrophy even when intensive training is begun at a very young age.

Relationship between physical properties of the arterial system and left ventricular performance in the course of aging and arterial hypertension

Abstract: The purpose of this work was to study interactions between physical properties of the arterial system and left ventricular performance during aging in normal and in hypertensive patients. Fifty patients were studied; 28 normal patients (age range 22 to 68 years) and 22 patients with essential hypertension (age range 23 to 63 years). Systemic arterial resistance (SAR) was determined by simultaneous measurement of cardiac output and aortic pressure, dp/dt max, ejection fraction (EF), mean velocity of fibre shortening (VCF), end-systolic pressure-end-systolic volume ratio (ESP/ESV), modulus of chamber stiffness (kp), left ventricular wall thickness (h), mass (m) and m/LVEDV ratio (LVEDV left ventricular end-diastolic volume) were obtained from simultaneous measurements of left ventricular pressure and volume (cine-angiograms). In 45 of these patients (25 normal and 20 hypertensive patients) pulse wave velocity (C) and characteristic impedance of the ascending aorta (Zc) were obtained by simultaneous measurements of aortic pressure 3.5 cm above the aortic ring and aortic radius (cine-angiography). In hypertensive patients ESP/ESV, kp, h, m, m/LVEDV, SAR, C and Zc were increased compared to normal subjects of similar age; EF, VCF, dp/dt max were unchanged. In normal patients the ESP/ESV ratio, kp, h, m, m/LVEDV ratio, SAR, C and Zc increased with age; there were no age-related changes in EF, VCF or dp/dt max. In both groups, there was a close relationship between the m/LVEDV ratio and Zc, the characteristic impedance of the ascending aorta. These results suggest that: (1) aging and arterial hypertension lead to similar changes in the physical properties of the arterial system and in left ventricular performance; (2) in both cases, the development of concentric cardiac hypertrophy is closely related to the physical properties of the arterial system.

The effect of intracoronary thrombolysis with streptokinase on myocardial thallium distribution and left ventricular function assessed by blood-pool scintigraphy

Abstract: In order to evaluate the effect of coronary recanalization in acute myocardial infarction, thallium scintigrams were made on admission in 23 patients in whom thrombolysis was attempted and in 27 patients treated conventionally. The scintigrams were repeated immediately after the procedure or after 3 h in the control group. No significant differences were apparent between the initial thallium uptake in treated patients or controls. Some degree of thallium redistribution occurred in 43 out of 50 patients. The degree of redistribution was greater in patients with open or recanalized arteries (redistribution 35%, s.d. 24% of initial defect) than in patients in whom the artery remained occluded (17%, s.d. 12%). No differences were apparent in six patients between the late scintigrams and a third series of images made after an additional injection of thallium. Global left ventricular function was analysed in 30 patients with anteroseptal infarction and in 35 patients with inferior wall infarction. Ejection fractions were lower in patients with anterior wall infarction. Between one and seven days after admission, ejection fractions were similar in patients with open or occluded arteries in pilot studies and in randomized patients with inferior wall infarction after thrombolysis or conventional treatment. In patients with anterior wall infarction, left ventricular ejection fraction after streptokinase (45%, s.d. 7%) was greater than after conventional treatment (38%, s.d. 12%). Analysis of segmental left ventricular function suggests that this difference is due in part to the improvement of segmental function in the non-infarcted areas. No differences were observed between ejection fractions measured early (1–7 days) or late (10–20 days) after myocardial infarction. The data show considerable overlap between patients treated with streptokinase and those treated conventionally. Further randomized trials are needed to determine whether thrombolysis in acute myocardial infarction does indeed result in permanent improvement of myocardial function.

Left ventricular function in men and women. Another difference between sexes

Abstract: In a group of 70 patients, 29 women and 41 men, with atypical chest pain and normal findings at coronary arteriography, some hemodynamic and angiographic parameters of left ventricular function were measured, for the purpose of determining the values of normality and to document possible differences between sexes. Of the diastolic parameters, the left ventricular end-diastolic pressure and volume was lower in women than in men, the LVEDP being 11.9 ± 3.4 against 13.7 ± 3.6 mm Hg ( P < 0.025), and ED V of 76.1 ± 15 against 89.5 ± 23 ml/m2 ( P < 0.005). Of the systolic parameters, the ejection fraction of 74 ± 7% in women was significantly higher than that of 67 ± 7% in men ( P < 0.0005), and so was the mean velocity of volume reduction of 2.59 ± 0.58 of women against that of 2.26 ± 0.35 of men ( P < 0.01). The physiological diversity between the sexes, with women showing a constant hyperdynamic condition in comparison to men, with smaller ventricular volumes and increased contraction, seems to offer a possible explanation for some intriguing aspects of the diagnosis of ischemic heart disease in the female sex.

Coronary recanalization in acute myocardial infarction: immediate results and potential risks

Abstract: Between September 1980 and March 1982, 83 patients were catheterized during the acute phase of their myocardial infarction with the intention to recanalize their infarct-related vessel (IRV); of these 83, 30 participated in a randomized study. Five patients died during the catheterization procedure, two as a result of cardiogenic shock, two of migration of thrombotic material and one of possible heart rupture after a successful recanalization. In 15 patients the IR V was found to be patent at the first coronary injection. In the remaining 64 patients with an occluded IRV, 41 arteries were successfully recanalized. Of the surviving patients who underwent an attempt at recanalization, 29 had non-fatal complications which required treatment (ventricular fibrillation, ventricular tachycardia or ventricular premature beats, bradycardia, hypotension, artrioventricular block, atrial fibrillation). The complications were predominantly observed in hypotensive patients during angiography after recanalization had been accomplished. Of the 41 successful recanalizations, complications occurred in 20. Of all recanalized right coronary arteries, complications took place in 81%, of the left circumflex arteries in 25% and of the left anterior descending arteries in 24%. In conclusion, catheterization and attempts at recanalization of occluded arteries impose a substantial risk of fatal and non-fatal complications. These occur in particular during the first angiogram after the re-opening of an occluded right coronary artery. These observations lead to the following recommendations: (1) streptokinase infusion should not be considered before the circulation is adequately supported: (2) lidocaine and nifedipine should be administered prophylactically before the attempt at recanalization; (3) a non-ionic contrast medium should be used for angiography.

Symptom prevalence in hypertensive patients.

Abstract: The influence of blood pressure levels on the prevalence of symptoms was studied in a group of 1771 untreated hypertensive patients referred to the Saint-Joseph Hypertension Clinic in Paris. Information on symptoms was obtained from a standardized physician-conducted interview during the patient's first visit at the outpatient clinic. The most frequent symptoms were headache (40.5%), palpitation (28.5%), nocturia (20.4%), dizzines (20.8%) and tinnitus (13.8%). Except for nocturia, symptom prevalence was higher in females than in males. In males as well as in females, no correlation was found between blood pressure levels and the presence of headaches, dizziness, palpitation and tinnitus when results were adjusted for age. In contrast, the relationship between two behavioural characteristics, anxiety and lack of regular physical activity, and symptom prevalence was more pronounced than the relationship with the blood pressure level itself. Moreover, the symptom prevalence reported differed significantly between the five permanent physicians of the clinic; comparison of results obtained by physician conducted interview and self-administered questionnaire indicated that differences between physicians were not due to differences in patient's characteristics but to differences in physician behaviour.

Echocardiographic documentation of regression of left ventricular hypertrophy in patients treated for essential hypertension

Abstract: One hundred and ninety-five patients with diastoiic systemic hypertension over 90 mm Hg were studied by serial echocardiography over five years of treatment. Satisfactory studies were obtained in 68 subjects with uncomplicated, untreated hypertension. In this group of patients during the five year period, there were significant decreases in systolic and diastoiic pressure that were associated with significant decreases in heart rate, left ventricular septal and posterior wall thickness, left ventricular end-systolic volume, left ventricular mass and the ratio of mean left ventricular wall thickness to left ventricular ratio. There were significant increases in the left ventricular end-diastolic volume, left ventricular stroke volume, fractional shortening of left ventricular enddiastolic diameter and ejection fraction. Echocardiography was more specific and sensitive in detecting the presence and the regression of left ventricular hypertrophy than either electrocardiography or the chest X-ray. The chronic treatment of systemic hypertension is associated with echocardiographic evidence of regression of left ventricular hypertrophy and of improvement in ventricular function.

Chamber compliance and myocardial stiffness in left ventricular hypertrophy.

Abstract: Left ventricular chamber stiffness is determined by the level of operating pressure and the diastolic pressurevolume relation. This relation is curvilinear and the slope of a tangent to the pressure-volume curve (operative chamber stiffness) increases as the chamber progressively fills. Such preload dependent changes in compliance occur during any acute alteration in ventricular volume. At a given diastolic pressure, operative chamber stiffness is determined by the relative values for ventricular volume and muscle mass and by the stiffness of a unit of myocardium. Thus, there may be a leftward shift of the diastolic pressure-volume curve (increase in the modulus of chamber stiffness) as a consequence of ventricular hypertrophy or an increase in the stiffness of heart muscle itself (increase in the modulus of muscle stiffness). To assess the stiffness of heart muscle, the myocardial stressstrain and stiffness-stress relations must be defined. Although some controversy exists with regard to the stiffness of hypertrophied myocardium, clinical studies suggest that chamber stiffness and myocardial stiffness can be normal or increased in the presence of left ventricular hypertrophy. These studies also suggest that increased myocardial stiffness develops in the presence of increased interstitial fibrosis. Moreover, isolated cardiac muscle experiments indicate that the increase in myocardial stiffness can be prevented when the connective tissue response is prevented. Quantitative measures of left ventricular chamber and myocardial stiffness contribute to the understanding of the pathophysiology of cardiac dyspnea and provide insight into functional and structural defects of hypertrophied myocardium.

Alcohol consumption and blood pressure in a French epidemiological study.

Abstract: We examined the relationship between alcohol consumption and blood pressure (BP) in a working population 723 men aged 20 to 59 years. In all 10-year age groups, means of both systolic and diastolic BP increased with level of alcohol intake, but this relationship was much less pronounced in subjects younger than 40 years. Similar findings were obtained for the prevalence of BP ≥ 160/94 mm Hg. There was no clear-cut evidence of a threshold level of alcohol intake in subjects aged less than 50 years. In the age group 50–59, a slightly higher mean BP non-drinkers than in moderate drinkers might be due to a higher prevalence of obesity among the former. Multivariate analysis showed that in subjects aged 40–59, the alcohol–BP association remained statistically significant when age and relative weight were controlled while it became non-significant in younger subjects. results were practically unchanged after adjustment for cigarette smoking, urinary sodium)potassium ratio, level of educational attainment. We conclude that the control of alcohol intake may be a means of preventing essential hypertension, along with the control of salt intake and adiposity.

Left ventricular wall thickness and plasma catecholamines in borderline and stable essential hypertension.

Abstract: It has been suggested that sympathetic overactivity has a pathogenetic relevance to left ventricular hypertrophic development, even apart from its effect on and in essential hypertension. To evaluate this possibility by echocardiographic and polygraphic methods, we studied left ventricular wall thickness and function and their possible relationship to plasma renin activity and plasma catecholamines in 11 normal subjects, 13 borderline hypertensives and 11 stable hypertensives without radiological or electrocardiographic signs of left ventricular hypertrophy. Compared with normal, borderline hypertensives showed an increase in interventricular septum (IVS) thickness ( P < 0.01) and IVS/posterior wall (PW) thickness ratio ( P < 0.01) together with an increased supine and upright plasma norepinephrine (NE; P < 0.01); there was also a decreased pre-ejection period (PEP; P < 0.01), PEP/left ventricular ejection time ratio ( P < 0.01) and total electromechanical systole ( P < 0.05). In stable hypertensives, PW thickness was greater than it was both in normals ( P < 0.01) and in borderline hypertensives ( P < 0.01) and IVS thickness was higher than in normals ( P < 0.05). Positive correlations between supine ( P < 0.001), upright ( P < 0.05) NE and both IVS thickness and IVS/PW thickness ratio were found in borderline but not in stable hypertensives. These results support the hypothesis recently put forward that IVS hypertrophy may represent an early stage of essential hypertension-induced LVH, which afterwards extends to the left PW; furthermore the results suggest that the sympathetic overactivity may play a role in the IVS hypertrophy development in borderline hypertensives.

Haemodynamic dose-response effects of intravenous beta-blocking drugs with different ancillary properties in patients with coronary heart disease.

Abstract: The haemodynamic dose-response effects of propranolol, practolol, oxprenolol and metoprolol were compared in a randomized single-blind study in 24 patients with stable coronary heart disease. The doses of drugs used gave approximately equal degrees of inhibition of exercise tachycardia. The haemodynamic profile in the control period was stable and similar in each group. All four drugs consistently reduced heart rate and cardiac output and increased pulmonary wedge pressure, but the changes were significantly greater after propranolol and metoprolol than after practolol and oxprenolol. There was no significant difference between the effects of the four drugs on calculated stroke volume. The increase in the calculated systemic vascular resistance was similar after all four drugs. These observations indicate that when administered intravenously to patients with coronary heart disease in equivalent negative chronotropic doses, drugs with intrinsic sympathomimetic activity (e.g. practolol and oxprenolol) resulted in less depression of left ventricular pumping function than drugs without this property. The possession of cardioselectivity (e.g. practolol and metoprolol) did not appear to confer any haemodynamic benefit.

Clinical course after attempted thrombolysis in myocardial infarction. Results of pilot studies and preliminary data from a randomized trial.

Abstract: Immediate results and follow-up are reported on 118 patients with a diagnosis of myocardial infarction who were included in studies on intracoronary thrombolysis at the Thoraxcenter. Pilot studies included 37 patients treated with streptokinase, nine with urokinase and six with nitroglycerine and nifedipine. First results of the present on-going randomized trial are described from 34 patients allocated to streptokinase therapy and 32 allocated to conventional therapy in the coronary care unit. Urokinase, nitroglycerine and nifedipine were not effective for recanalization. Streptokinase resulted in recanalization of 22 out of 29 occluded arteries in the pilot studies (71%), as well as 19 out of 23 occluded arteries in the randomized trial (83%). Five patients died during angiography and attempted recanalization. In the pilot studies, four patients died during follow-up. In none of these had recanalization been achieved. On the other hand, angina and reinfarction were observed more frequently in patients after successful recanalization. In the randomized trial no differences were observed in mortality, reinfarction rate, angina or results of predischarge stress testing between patients allocated to streptokinase treatment or controls. However, cardiac -failure during follow-up seemed to be more prominent in controls. These preliminary data indicate that the clinical course in patients after attempted thrombolysis is similar to the course of patients treated by conventional methods. Both should be monitored carefully for signs of cardiac failure and episodes of myocardial ischemia and appropriate measures, including surgery, should be considered if these appear. Further randomized trials are warranted to determine whether patients after thrombolytic therapy have a better survival and fewer complications than patients treated conventionally.

Incidence and prognosis of acute myocardial infarction among men below age 40 in Göteborg, Sweden

Abstract: All cases of acute myocardial infarction occurring in the community of Goteborg in certain age groups have been registered in an Infarction Register for more than a decade. All survivors have systematically been followed-up at a special Postmyocardial Infarction Clinic. Sixty-one cases of myocardial infarction below the age of 40 were registered through the years 1968–78. Fifteen men died either outside hospital or in hospital in the acute stage. The annual incidence of a first myocardial infarction was low — 6.1 and 29.4 per 100 000 males in the age groups 30–34 years and 35–39 years, respectively. However, the incidence among Finnish immigrants was significantly higher than among other groups, the figures being similar to those reported from Helsinki. Compared with older patients, the survivors below the age of 40 seemed to have larger and more complicated infarcts. During an II-year follow-up the mortality was significantly lower among patients below the age of 40 than in older age groups. The incidence of non-fatal reinfarctions and the prevalence of angina pectoris did not differ between the groups. The non-fatal reinfarctions could not be predicted from primary or secondary risk factors.

Complications of exercise testing. A survey in three German-speaking countries.

Abstract: A survey was carried out of 1 065 923 individual exercise tests performed at 198 sites in three German-speaking countries. Seventeen deaths were reported among 712 285 patients, in 80% of whom coronary heart disease was either established, suspected, or ruled out. Fatal complications were unrelated to exercise technique, attained workload, or selection. The cause of death in these patients was myocardial infarction; 10 additional non-fatal infarctions were reported. Among 353 638 young, apparently healthy, athletes, no deaths or life-threatening complications were reported. The most common non-fatal, life-threatening complication was ventricular fibrillation, which occurred at a rate of 1.4 per 10 000 tests employing bicycle ergometry. It was not observed among 83 000 procedures with an arm-assisted step test. In comparison to the results from the United States in the National Survey of Exercise Stress Testing (1980) the mortality rate in Europe appears to be lower (Europe 0.25 per 10 000, U.S.A. 0.5 per 10 000). In addition, the total number of severe complications was lower in Europe (Europe 1.4 per 10 000, U.S.A. 8.8 per 10 000). It is concluded that exercise testing is a relatively safe procedure when all possible precautions, including the availability of a defibrillator, have been taken. The observed differences in the non-fatal complication rates for various types of exercise require further clarification.

Platelet counts and aggregates in coronary artery disèase

Abstract: Platelet counts and aggregates have been measured in arterial, coronary sinus and peripheral venous blood in groups of patients with and without coronary artery disease, and under various conditions associated with myocardial ischaemia. No changes in platelet counts were observed. An increase in platelet aggregates across the coronary vascular bed was observed during spontaneous or ergometrine-induced ischaemia, but not with pacing-induced angina nor at the onset of coronary occlusion causing infarction. Platelet aggregates were high in systemic blood samples from patients with frequent episodes of spontaneous angina but not in samples from patients with stable effort angina, nor were they increased with exercise-induced angina or after myocardial infarction. The findings suggest that platelet aggregates are found in coronary sinus blood when there is very severe proximal narrowing (but not complete occlusion) of a coronary artery sufficient to cause cardiac pain at rest, but not when proximal constriction is less severe and the ischaemia is pacing-induced. Increased platelet aggregates in systemic blood samples may be a marker of recent episodes of rest pain.

Serum myoglobin determinations in the assessment of acute myocardial infarction.

Abstract: Serum myoglobin (SMb) changes following acute myocardial infarction were studied in 67 patients admitted to the coronary care unit soon after the onset of symptoms (mean delay 2.8 ± 2.2 h; CK on admission < 150 iu/l). A typical rise and fall of SMb concentrations was seen in all cases. The maximum SMb level (718 ± 301 ng/ml) was reached 7.2 ± 3.7 h after admission. Return to values lower than 80 ng/ml was observed after a mean time of 36.2 ± 20.9 h. SMb peak concentration correlated significantly with both serum enzyme peak level and cumulated CK activity (r=0.64, P < 0.0001). The myoglobin release patterns were recorded in 121 patients. The twenty-four patients whose SMb levels remained higher than 100 ng/ml 48 h following admission demonstrated a higher incidence of left ventricular failure (Killip classes III and IV) and a mortality rate of 33%. Patients who died within three months following hospitalization (n=10) showed significantly more elevated myoglobin concentrations throughout the investigation period as compared to survivors (n=111). Myoglobin determined 4 h following admission correlated with serum lactate dehydrogenase activity, and high SMb levels were associated with an increased mortality rate. Our results suggest that SMb measurements might allow a stratification of patient risk as early as 9 to 12 h following the onset of myocardial infarction.