[Intensity and duration of pain in acute myocardial infarction].
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Humans↗
Biomedical subjects
A Hjalmarson
Publications and source records attributed to A Hjalmarson.
QRS complex recovery during one year after acute myocardial infarction.
The recovery of the ECG signs of anterior myocardial infarction has been studied in 70 patients. A significant increase in R-wave amplitude and decrease in Q-wave amplitude on 24-lead precordial mapping was observed during one year after infarction. Patients with lower initial heart rate showed a greater recovery of R- and Q-wave amplitudes, as did patients with smaller infarcts, as assessed by peak heat-stable lactate dehydrogenase (LDH).
Adult↗
Occurrence of anterior ST depression in inferior myocardial infarction and relation to clinical outcome.
In 229 patients admitted to the coronary care unit (CCU) at Sahlgren's Hospital developing inferior myocardial infarction, and with no previous myocardial infarction, the clinical outcome was related to the presence of ST-segment depression in 16 anterior chest leads. In all, 64% had anterior ST-segment depression. These patients differed from those not having ST depression in several aspects. They had larger infarcts, as assessed by serum enzyme activity and ECG recording. They were more prone to congestive heart failure and required more treatment for this complication. Their intensity and duration of pain during the first 4 days appeared to be more substantial. During a 5-year follow-up, patients with anterior ST depression tended to have a higher mortality. We conclude that among patients with inferior myocardial infarction and no previous infarction, those with anterior ST-segment depression form a subgroup with a more severe clinical course.
Adult↗
Five-year mortality rate in relation to enzyme-estimated infarct size in acute myocardial infarction.
In 727 patients with acute myocardial infarction, different enzyme variables reflecting infarct size were related to the 5-year mortality rate. The maximum activity of serum heat-stable lactate dehydrogenase (LD), analyzed every 12 hours for 48 to 108 hours, was significantly associated with the 5-year mortality rate when patients with a first myocardial infarction were evaluated (p less than 0.001), and similarly (p less than 0.001) when patients with a previous myocardial infarction were included in the analyses. Very similar results were found when the maximum activity of aspartate aminotransferase (ASAT) analyzed once daily for 3 days was related to the mortality rate over 5 years, whereas the maximum activity of creatine kinase (CK) and CK subunit B analyzed every 6 hours for 48 hours in a subset of patients did not predict the outcome to the same extent. The results from LD and ASAT analyses clearly indicated that the association between infarct size and 5-year mortality rate was caused by the much higher mortality rate in patients with larger infarcts during the first year after onset of infarction, whereas after the first year, incidence of death appeared to be independent of the original infarct size. Thus we conclude that although a highly significant relationship between infarct size and overall 5-year survival was found, the mortality rate seemed to be higher in patients with larger infarcts, particularly during the first year after infarction.
Adult↗
Cardiotoxic effects of catecholamines in guinea-pig (Cavia porcellus) and in albino rat (Rattus norvegicus). A comparative study.
1. Cardiotoxic effects of catecholamines in guinea-pigs and rats were compared. Substantially lesser cardiotoxic effects of isoprenaline (2 X 40 mg/kg b.w.) were found in guinea-pigs, as judged by morphologic examination. 2. When isolated hearts were perfused in vitro, noradrenaline (5 X 10(-6) M) induced less damage, judged by enzyme leakage (ASAT) and electron microscopy analysis. 3. Myocardial ATP and creatine phosphate are normally higher in guinea-pigs than in rats, and no difference was found between the two species when subjected to noradrenaline. 4. Glycogen was higher in guinea-pig myocardium, and glycogenolysis during noradrenaline perfusion was substantially greater in guinea-pig hearts than in rat hearts. 5. Obtained data are interpreted with respect to the recent findings that, not only natural history, but also some physiological traits [blood gas transporting system (Kreuzer and Turek, 1981, Medizinische Aspekte der Höhe, pp. 15-23)] make guinea-pigs similar to high altitude mammals, and to earlier findings that high altitude hypoxia adapted rats display lesser vulnerability of cardiac muscle by anoxia and by catecholamines.
Animals↗
Mortality and morbidity in suspected acute myocardial infarction in relation to ambulance transport.
In 681 patients admitted to the coronary care unit (CCU) at Sahlgrenska hospital between 1 May 1983 and 31 May 1984, due to suspected acute myocardial infarction (MI), the hospital mortality and morbidity were related to whether the patients were transferred to hospital by ambulance or not. In the ambulance group acute MI developed in 48% (during the first 3 days in hospital) compared with 41% in the non-ambulance group (P = 0.10). The overall mortality rate was 10.4% in the ambulance group versus 3.8% in the non-ambulance group (P = 0.001). Corresponding figures for MI patients were 19.3% versus 9.1% (P = 0.02). In all, patients referred by ambulance had larger infarcts according to maximum serum enzyme activity and a higher incidence of congestive heart failure. Similar findings were observed when MI patients were analysed separately. On the other hand, the incidence of ventricular fibrillation, requirement for lidocaine, and the course of pain was fairly similar in the two groups. In a multivariate analysis, infarct size was the major independent predictor for early mortality rate. We conclude that patients who call for an ambulance due to suspected acute MI appear to have a different early mortality and morbidity pattern compared to those who do not. The most obvious observation was a higher early mortality. These patients therefore might be the most suitable candidates for early intervention studies.
Adult↗
Effect of corticosteroids on muscarinic receptors on cultured myocardial cells.
Rat myocardial cells in tissue culture were utilized to investigate modulation by corticosteroids on muscarinic receptor affinity. Competition binding experiments between tritiated quinuclidinyl benzilate and carbachol were performed on the muscarinic receptor both on whole cells and on a crude membrane preparation from cultured myocardial cells. Hydrocortisone was shown to promote a transition of the high affinity site of the muscarinic receptor towards super-high affinity. This was analogous with the effect of divalent ions. The affinity shift was detectable after 6 hr exposure to 0.1 microgram/ml of hydrocortisone in the tissue culture dishes but was abolished by concomitant incubation with a protein synthesis inhibitor (10 microM puromycin). The response on agonist binding of Gpp(NH)p in the presence of manganese ions was altered indicating that the adenylate cyclase-coupled muscarinic receptor nucleotide binding protein was modulated. No effects of corticosteroid exposure were noted on phosphatidyl inositol turnover.
Animals↗
Do results from major clinical trials indicate a change in management in the acute phase of myocardial infarction?
Since introduction of modern Coronary Care Units, hospital mortality has been reduced by about 50%. This is most likely due to a number of treatments that today are well established. Those include detection and treatment of serious arrhythmias with antiarrhythmic agents and electrical conversion, and more aggressive early treatment of congestive heart failure, of chest pain, and of atrioventricular (AV) block and bradyarrhythmias. The new goals in early management of suspected acute myocardial infarction must aim at prevention and limitation of ischemic damage. The use of beta-blockers has been widely studied. Data from 27 randomized trials with a total of about 27,000 patients have convincingly shown that early beta-blockade reduces mortality, prevents and limits infarct development and arrhythmias, and reduces infarct complications. Three large trials, the Göteborg and MIAMI Trials on metoprolol and the ISIS Trial on atenolol, have demonstrated significant beneficial effects and good tolerance. Thrombolytic therapy in patients with signs of acute myocardial infarction, mainly streptokinase, has demonstrated significant reduction of short-term mortality. The large Italian GISSI Trial, including almost 12,000 patients, showed very significant reduction in 21 day mortality by streptokinase, and the earlier treatment started, the better the reduction. Pooling all published studies in the literature also shows the same favorable effects on mortality. Early treatment with thrombolytic therapy might also prevent and limit infarct development and preserve myocardial function. Recent large scale studies have convincingly demonstrated the value of early beta-blockade and of thrombolytic therapy in selected patients with signs of acute myocardial infarction. It seems reasonable to change the management in the acute phase of myocardial infarction based upon recent major clinical trials.
Adrenergic beta-Antagonists↗
Long-term prognosis in relation to ECG findings in acute myocardial infarction.
In 680 patients with acute myocardial infarction the prognosis during the following 5 years was related to observations made in a standard electrocardiogram (ECG) and 24 precordial chest leads. Patients with a Q-wave infarction (based on a 12-lead standard ECG) had a mortality rate during hospitalization of 10.2% which was much higher than that in patients with a non-Q-wave infarction (1.9%, p less than 0.001). At 5 years' follow-up 33.6% of those with a Q-wave infarction had died versus 28.4% of those with a non-Q-wave infarction (p greater than 0.2). Corresponding mortality rate among patients with no previous infarction (n = 587) was 32.1% and 25.2%, respectively (p = 0.17). In patients with anterior infarction and no previous infarction there was no correlation between Q- and R-wave changes in the 24 chest leads 4 days after admission to hospital and 5-year mortality rate. We thus conclude that patients with a Q-wave infarction had a higher in-hospital mortality compared with non-Q-wave infarction as judged from standard ECG, whereas 5-year mortality was similar. Similarly, there was no correlation between Q- and R-wave changes in an increased number of chest leads and 5-year mortality rate.
Adult↗
[Patients with suspected and unverified myocardial infarction--prognosis].
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Humans↗
Variations in the HCN/HNC abundance ratio in the Orion molecular cloud.
We have used observations of the rare isotopes of HCN and HNC to determine the relative abundance of these two chemical isomers along the central ridge of the Orion molecular cloud. The abundance ratio [HCN]/[HNC] decreases by more than an order of magnitude from the relatively warm plateau and hot core sources toward the KL nebula to the colder, more quiescent clouds to the north and south. Even in the cooler regions, however, the ratio is an order of magnitude larger than that found in previous investigations of cold dark clouds. We determine the kinetic temperature in the regions we have studied from new observations of methylacetylene (CH3CCH), together with other recent estimates of the gas temperature near KL. The results suggest that the warmer portions of the cloud are dominated by different chemical pathways than those in the general interstellar cloud material.
Alkynes↗
Appearance of T-wave inversions without raised serum enzyme activity in suspected acute myocardial infarction: clinical outcome in relation to subendocardial infarction.
In 67 patients with a clinical history of suspected acute myocardial infarction (MI) who developed T-wave inversions in standard ECG and had normal serum aspartate aminotransferase activity (possible MI) the clinical outcome was compared with that in patients fulfilling criteria for subendocardial infarction. Patients with possible MI had a lower mortality (p = 0.02) and also a lower reinfarction rate (p = 0.14) during the first 2 years as compared with those with subendocardial MI. Although patients with subendocardial MI had more problems with chest pain in the acute phase, angina pectoris occurred more frequently in patients with possible MI during a longer follow-up period. Congestive heart failure occurred more frequently in patients with subendocardial MI during initial hospitalization, whereas treatment for heart failure appeared similar in the two groups during a longer follow-up time. We conclude that the clinical course in patients with possible MI, here defined as chest pain and appearance of T-wave inversions without elevation of serum enzyme activity, seems to differ from that in patients with subendocardial MI, particularly regarding long-term survival and incidence of angina pectoris.
Adult↗
Chest pain in acute myocardial infarction: a descriptive study according to subjective assessment and morphine requirement.
In 722 patients with suspected acute myocardial infarction (MI) we have tried to describe the course of chest pain according to their own assessment and morphine requirement. Patients were asked to score pain from 0-10 every second hour after arrival in the coronary care unit (CCU) and also to score their maximal pain at home. A very high intensity of chest pain was observed at home (mean score 7.1). At arrival in the CCU the mean pain score already had declined to 1.8, although 51% still had chest pain. Pain score declined successively during the first 12 hours in the CCU. At 24 hours after arrival, 20% still had some chest discomfort. In one quarter of the series a score of more than 0 was observed later than 24 hours after arrival in CCU. Patients developing definite MI had, as expected, a longer duration of pain and a much higher requirement of morphine compared with those with no MI. The difference between MI and no MI patients regarding subjective assessment of the initial intensity of pain at home and in hospital was, however, surprisingly low.
Adult↗
Beta blockade and chest pain in acute myocardial infarction.
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Adrenergic beta-Antagonists↗
The influence of early intervention in acute myocardial infarction on long-term mortality and morbidity as assessed in the Göteborg metoprolol trial.
The mortality and morbidity were assessed during a 2-year follow-up in an acute intervention trial in suspected acute myocardial infarction with metoprolol (a selective beta 1-blocker). On admission to the trial, the 1395 participating patients were randomly allocated to metoprolol or placebo for 3 months. Thereafter, if there was no contraindication, patients with infarction and/or angina pectoris were continued on metoprolol for 2 years. A lower mortality was observed after 3 months in patients randomised to metoprolol. The difference remained after 2 years. The difference in 2-year mortality rate was restricted to patients randomised early after onset of pain. Late infarction was observed more often in the placebo group during the first 3 months. When the two groups thereafter were treated similarly, the difference successively declined and did not remain after 2 years. A similar incidence of angina pectoris was observed in the two groups at each check up. During the early recovery period, more patients in the metoprolol group returned to work. No such difference was observed later on.
Adult↗
Variability of chest pain in suspected acute myocardial infarction according to subjective assessment and requirement of narcotic analgesics.
In 653 patients with suspected acute myocardial infarction the course of pain according to subjective assessment and morphine requirement is described. Patients were asked to score pain from 0-10 until a pain-free interval of 12 hours appeared. Different categories of patients constructed from clinical aspects were compared. Although the variability between groups was fairly small, subgroups were found in which the initial intensity of pain was more marked and the duration of pain was longer. Thus patients with larger infarcts according to maximum serum enzyme activity and patients with Q-wave infarction had more severe pain initially and also a longer duration and a higher morphine requirement compared with patients with a lower serum enzyme activity or a non-Q-wave infarction. Other groups with a more severe course of chest pain were those with more intensive pain at home, electrocardiographic signs of acute myocardial infarction on admission to hospital, and finally those with a high systolic blood pressure or a high rate-pressure product on admission to the Coronary Care Unit. We thus conclude that there is a variability of chest pain in suspected acute myocardial infarction and that there are defined groups of patients in which a more severe course of chest pain could be expected.
Adult↗
Natural evolution of left ventricular haemodynamics following uncomplicated acute myocardial infarction.
In an attempt to investigate the changes in left ventricular haemodynamics following uncomplicated myocardial infarction 95 patients with definite electrocardiographic signs of infarction, without clinical signs of cardiac failure, were monitored with a Swan Ganz catheter for the first 24 hours after admission to hospital. The median delay from onset of symptoms was 6.8 hours. Mean heart rate increased (83-86 beats/min; P less than 0.05) while stroke volume index fell (38.4-36.6 ml/m2; P less than 0.05); cardiac index therefore remained unchanged during the observation period. As a result of a fall in arterial pressure both systemic vascular resistance and left ventricular stroke work index fell significantly (P less than 0.01). Pulmonary wedge pressure also fell (13.6-10.5 mm Hg; P less than 0.001), but this fall was confined to patients whose initial reading was above the median of 13 mm Hg. Pulmonary wedge pressure fell both among the 41 patients who required some medical therapy (15.6-10.8 mm Hg; P less than 0.001) and the 54 who received no medication throughout the 24 hours (12.0-9.8 mm Hg; P less than 0.05). The 39 patients with anterior wall infarction had higher baseline pulmonary wedge pressure and systemic vascular resistance than the 42 with inferior wall infarction. Later the stroke volume and stroke work index were persistently lower reflecting the greater degree of impairment of left ventricular function in anterior wall infarction. In conclusion, following an uncomplicated myocardial infarction, cardiac index was maintained, despite a fall in stroke volume, by an increase in heart rate. Pulmonary wedge pressure showed both a spontaneous fall and a fall in those patients given additional medical therapy during the study period.
Aged↗
Observational astrochemistry.
Astronomers have identified some 70 molecular species in dense interstellar clouds and the envelopes expelled by evolved stars. Some 75% of these are organic, including molecules with up to 13 atoms and with weights up to 147 daltons. Elements found in interstellar compounds include H, C, N, O, S, Si, and probably Cl. A recent addition to the list of interstellar molecules is the first hydrocarbon ring, cyclopropenylidene (C3H2). Current research in astrochemistry is concentrating on the determination of accurate chemical abundances as a function of environment. Both basic similarities and intriguing differences among clouds are found, which may provide clues to processes associated with cloud evolution and star formation.
Astronomical Phenomena↗