QT dispersion may be a useful adjunct for detection of myocardial infarction in the chest pain center

BACKGROUND: QT dispersion has been proposed as a noninvasive measurement of the degree of inhomogeneity in myocardial repolarization. Increased QT dispersion has been reported after myocardial infarction. We hypothesized that increased QT dispersion may be a useful adjunct for risk stratification in patients being evaluated in a chest pain center. METHODS AND RESULTS: Patients were admitted to the chest pain center for evaluation of chest pain. Exclusion criteria included (1) systolic blood pressure <90 mm Hg, (2) ischemia or infarction on the initial electrocardiograph (ECG), (3) elevated creatine kinase or MB fraction, and (4) chest pain associated with cocaine use. Serial creatine kinase and MB levels and ECGs were obtained at 0, 6, and 9 hours. Patients were monitored for (1) creatine kinase and MB rise, (2) ECG changes for infarction, (3) ST-segment changes, and (4) rest angina. A negative evaluation at the chest pain center led to an exercise stress test. Patients with a positive exercise stress test were admitted for further evaluation and patients with a negative exercise stress test result were discharged home. Patients were divided into 3 groups. Group 1 consisted of patients who were found to have an acute myocardial infarction (AMI), group 2 consisted of patients with prior history of coronary artery disease but no evidence of AMI, and group 3 consisted of patients without prior coronary artery disease or AMI. QT dispersion was measured on the initial ECG in all patients. A total of 586 patients were evaluated. Group 1 consisted of 13 patients with mean QT dispersion of 44.6+/-18.5 ms, group 2 consisted of 267 patients with a mean QT dispersion of 10.0+/-13.8 ms, and group 3 consisted of 303 patients with a mean QT dispersion of 10.5+/-10.0 ms. Analysis of variance showed a significantly higher QT dispersion in patients who had AMI compared with other patients with chest pain (P< .001). CONCLUSIONS: QT dispersion can be a useful diagnostic adjunct for detection of AMI in patients with chest pain with a normal ECG and normal cardiac enzymes.     

Spontaneous angina in the coronary care unit. 2. Electrocardiographic changes during and after chest pain

Serial ECGs of 16 patients with repetitive attacks of spontaneous angina in the CCU were studied from admission to the hospital to the follow-up phase at the cardiac clinic. Transient repolarization ECG changes occurring during unprovoked angina included ST-segment elevation and ST-segment depression, alterations of T-wave amplitude and polarity, and pseudonormalization of previously inverted T-waves. In addition, QRS complexes were altered transiently during chest pain. Such changes comprised augmentation or reduction of amplitude of R and S waves, widening of QRS complexes and a merging of R waves with the elevated ST-segments. Occasionally the ECG during attacks of angina did not show any change. During asymptomatic periods, between attacks of spontaneous angina, the ECG either returned to baseline, or displayed minor ST-segment shifts, and/or T-wave alterations of varying durations. However, such changes became either persistent or were replaced in the late course of hospitalization by ECG alterations diagnostic of transmural or nontransmural myocardial infarction. Twelve patients suffered an acute myocardial infarction. Four patients died within one month of admission. During follow-up of the 12 surviving patients in the cardiac clinic, amelioration of T-wave changes was noted in the ECGs of patients who remained asymptomatic, but new ischemic alterations were seen in the ECG of patients who had recurrent angina, or were readmitted to the hospital for evaluation. Increase in the amplitude of R-waves, disappearance of Q-waves, or reduction of Q-wave depth were noted at follow-up, in comparison with the discharge ECG, in some patients who had suffered primarily an anterior myocardial infarction.     

Normal frontal perfusion in patients with frozen gait

With the aim to compare the diagnostic efficacy as regards acute myocardial infarction of two rapid dry-strip tests, one with both creatine kinase MB (CK-MB) and myoglobin (C + M) and the other with troponin T, and to test the reliability of bedside diagnosis by the coronary care unit (CCU) nurse, 151 patients with acute chest pain admitted to the CCU were investigated. There was no difference in diagnostic performance between rapid tests and quantitative determinations. With <6-hour duration of symptoms, the sensitivity was better for C + M than for troponin T (72% vs 33%, p < 0.05). With symptoms lasting >12 hours on arrival, troponin T performed better, with 100% sensitivity and a negative predictive value of 100% in the 6-hour retest. For exclusion of damage, the two tests have similar and reliable diagnostic capacities 12 hours after the onset of symptoms. The bedside diagnosis or exclusion of acute myocardial infarction was carried out rapidly (within 20 minutes) and reliably by the CCU nurses.     

A decision tree for the early diagnosis of acute myocardial infarction in nontraumatic chest pain patients at hospital admission

STUDY OBJECTIVE: To find an accurate algorithm for the diagnosis of acute myocardial infarction in nontraumatic chest pain patients on presentation to the emergency department. DESIGN: In a prospective clinical study, we compared the diagnostic performances of clinical symptoms, presenting ECG, creatinine kinase, creatine kinase MB activity and mass concentration, myoglobin, and cardiac troponin T test results of hospital admission blood samples. By classification and regression trees, a decision tree for the diagnosis of acute myocardial infarction was developed. SETTING: Emergency room of a Department of Internal Medicine (University Hospital). PATIENTS: One hundred fourteen nontraumatic chest pain patients (median delay from onset of chest pain to hospital admission, 3 h; range, 0.33 to 22): 26 Q-wave and 19 non-Q-wave myocardial infarctions, 49 patients with unstable angina pectoris, and 20 patients with chest pain caused by other diseases. MEASUREMENTS AND RESULTS: Of each parameter taken by itself, the ECG was tendentiously most informative (areas under receiver operating characteristic plots: 0.87 +/- 0.04 [ECG], 0.80 +/- 0.08 [myoglobin], 0.80 +/- 0.04 [creatine kinase MB mass], 0.77 +/- 0.04 [creatine kinase activity], 0.69 +/- 0.06 [clinical symptoms] 0.67 +/- 0.06 [creatine kinase MB activity], 0.67 +/- 0.05 [troponin T]). In patients presenting 3 h or less after the onset of chest pain, ECG signs of acute transmural myocardial ischemia were the best discriminator between patients with and without myocardial infarction. In patients presenting more than 3 h, however, creatine kinase MB mass concentrations (discriminator value, 6.7 micrograms/L) were superior to the ECG, clinical symptoms, and all other biochemical markers tested. This algorithm for diagnosing acute myocardial infarction was superior to each parameter by itself and was characterized by 0.91 sensitivity, a 0.90 specificity, a 0.90 positive and negative predictive value, and a 0.90 efficiency. CONCLUSIONS: We found an algorithm that could accurately separate the myocardial infarction patients from the others on admission to the emergency department. Therefore, this classifier could be a valuable diagnostic aid for rapid confirmation of a suspected myocardial infarction.     

Class I-restricted cross-presentation of exogenous self-antigens leads to deletion of autoreactive CD8(+) T cells

Intracoronary thrombosis plays a key role in the pathogenesis of acute myocardial infarction (AMI), and the formation of an occlusive thrombus usually precedes the development of myocardial damage. Therefore we evaluated and compared the early sensitivities of thrombin-antithrombin III complex (TAT), D-dimer, myoglobin, creatine kinase (CK) MB mass concentration, and cardiac troponin T (cTnT) on admission to a coronary care unit (CCU) before heparin or thrombolytic therapy was started. We investigated 31 consecutive patients admitted to CCU for evolving AMI within 6 hours from the onset of infarct-related symptoms; the median delay from chest pain onset to CCU admission was 135 minutes. Of all biochemical markers tested TAT had the highest early sensitivity on admission to the CCU, and TAT was significantly more sensitive than cTnT, CKMB mass, myoglobin, and D-dimer. However, TAT increases give no information about the location of clot formation in the body, and the diagnosis of AMI must be subsequently verified by an increase in more cardiac specific proteins, such as troponins or CKMB.     

Hepatocyte growth factor/scatter factor stimulates chemotaxis and growth of malignant mesothelioma cells through c-met receptor

AIMS: To assess the ability of clinical characteristics, admission ECG and continuous ST segment monitoring in determining long-term prognosis in unstable angina. METHODS: Two hundred and twelve patients with unstable angina (mean age 59 years), presenting within 24 h of an acute episode of angina were recruited at three hospitals and treated with standardized medical therapy. All patients kept chest pain charts and underwent ST segment monitoring for 48 h. The occurrence of death, myocardial infarction, and need for revascularization was assessed over a median follow-up of 2.6 years. RESULTS: The risk of death of myocardial infarction was greatest in the first 6-8 weeks after admission. Admission ECG ST depression and the presence of transient ischaemia predicted increased risk of subsequent death or myocardial infarction, whereas a normal ECG predicted a good prognosis. In 14 patients, ST segment monitoring provided the only evidence of recurrent ischaemia, and 72% of this group suffered an adverse event. Transient ischaemia and a history of hypertension were the most powerful independent predictors of death or myocardial infarction. CONCLUSIONS: Adverse events in unstable angina occur early after admission and can be predicted by clinical and ECG characteristics, and by the presence of transient ischaemia during ST segment monitoring. Risk stratification by these simple assessments can identify patients with unstable angina at high risk.     

Acute aortic dissection complicated with acute myocardial infarction--a case report of successful operation for the case of DOA

A 61-year-old woman who suddenly manifested chest and back pain was admitted after the diagnosis of acute type A dissection complicated with acute inferior myocardial infarction at another hospital. While being transported to our hospital by ambulance, her ECG repeatedly demonstrated ventricular fibrillation of cardiac arrest. She was in the state of dead on arrival (DOA) when arrived at our hospital. ECG demonstrated complete A-V block and cardiac arrest alternately. However, soon after right ventricular pacing was done, her blood pressure increased and she recovered consciousness. We therefore performed an emergency operation. We performed reconstruction of the ascending aorta and right coronary bypass grafting, since she had aortic dissection and conus brach avulsion. The postoperative course was uneventful.     

Unstable angina in coronary intensive care units without hemodynamics: is admissible a strategy limiting the indications for coronarography?

In coronary care units (CCU) without cardiac catheterization facilities, coronary angiography is rarely carried out when a successful medical treatment in the acute phase of unstable angina has been obtained. However, the unstable angina still has an uncertain prognosis when the remission of pain is obtained with drugs. This study presents a follow-up of 147 consecutive patients (aged 66.8 +/- 10.4 years) admitted to our CCU in 1991 and 1992 for unstable angina; 33 of them (22.4%) were in Braunwald class I. 2 (1.4%) in class II and 112 (76.2%) in class III. The patients were treated according to the usual therapy protocols and class III patients received i.v. heparin. In selected cases we used thrombolysis (10 patients) and intra-aortic balloon pump (5 patients). During hospitalization 1 patient died (0.7%), 5 patients (3.4%) suffered an acute myocardial infarction and 9 patients (6.1%) had angina. Stabilization of unstable angina was achieved in 132 patients (89.9%): in 113 (76.8%) during the first 48 hours, and in 19 (12.9%) later. Coronary angiography was carried out in non-stabilized patients and in 46 (34.8%) of the 132 with successful treatment (Group I). Eighty-six patients, without indication to coronary angiography were discharged in medical therapy (Group II). During the follow-up (mean of 15.0 +/- 9.0 months) Group I 10 patients (18.2%) had cardiac events (death, myocardial infarction, or recurrent angina) vs 26 of Group II (p < 0.05). In Group I coronary angiography together with clinical criteria of high risk allowed the identification of candidates to coronary revascularization (61.8% of Group I patients while). These data show that the initial success of treatment during the acute phase of unstable angina should not be considered as a favourable prognostic index. Coronary angiography appears to be indicated for clinical evaluation and therapeutical decision.     

Direct admission to the coronary care unit by the ambulance service for patients with suspected myocardial infarction

BACKGROUND: Direct access to the coronary care unit (CCU) for general practitioner (GP) referred cases of suspected acute myocardial infarction (AMI) (fast track admission) substantially reduces the time to thrombolysis. Until now, this policy has been confined to GP referrals. OBJECTIVES: To determine the time taken to admission to CCU under the fast track policy (ambulance referrals and GP referrals) and the time taken to start administration of thrombolytics (ambulance referrals, GP referrals, and accident and emergency referrals). METHODS: Fast track admission policy was extended to include referrals from ambulance personnel who respond to emergency service calls. Ambulance personnel referred cases were also examined to see if they were referred appropriately to the CCU. RESULTS: 100 ambulance personnel referrals and 260 GP referrals to CCU with chest pain were studied. Forty accident and emergency referrals who had AMI requiring thrombolysis were also studied. In the ambulance referred group the time to admission from phone call was a median of 10 minutes (range 2 to 45), a saving of 30 minutes compared with GP referrals (median 40 minutes, range 2 to 217). The median diagnostic electrocardiogram (ECG) to thrombolysis time was longer in the accident and emergency referrals with AMI than either ambulance referrals or GP referrals admitted under the fast track policy. Diagnostic ECG to thrombolysis time: accident and emergency 50 minutes (range 15 to 385); ambulance referrals median 33 minutes (range 6 to 69); GP referrals median 29.5 minutes (range 5 to 110 minutes); (p = 0.056 accident and emergency compared with ambulance referrals, p < 0.002 accident and emergency compared with GP referrals). Of 100 ambulance referrals 52 patients exhibited symptoms suggestive of ischaemic heart disease (confirmed AMI, unstable angina, and angina) and a further 18 patients were required to stay in CCU for other cardiac problems. Thus a total of 70 (70%) were considered appropriate compared with 155 of 260 (55.8%) GP referred cases. CONCLUSIONS: Extending the fast track admission policy to ambulance personnel reduces delay to admission for patients with suspected MI without adversely affecting the appropriateness of admissions.     

Pseudoaneurysm of femoral artery after catheterisation: treatment by a mechanical compression device guided by colour Doppler ultrasound

A 28-year-old woman presented to the emergency department for evaluation of acute chest pain. She lacked risk factors for coronary artery disease and her initial electrocardiogram (ECG) was nondiagnostic. Within 45 minutes of presentation she developed nausea, vomiting, restrosternal chest pain, and ECG changes compatible with an acute inferoposterior myocardial infarction. Emergent cardiac catheterization revealed three-vessel coronary artery ectasia and two-vessel occlusion. She underwent emergency coronary artery bypass grafting. Her myocardial ischemia was believed to have been induced by methergine, which she had been taking over the preceding 3 days. The etiology and pathophysiology of coronary artery ectasia, as well as the cardiovascular effects of methergine and a related drug, ergotamine, are discussed.     

Prognosis in men and women coming to the emergency room with chest pain or other symptoms suggestive of acute myocardial infarction

BACKGROUND: Previous studies suggest a gender-related difference in prognosis among patients with ischaemic heart disease. In the present study, we aimed to describe the characteristics and prognosis among patients with suspected ischaemic heart disease in relation to gender. METHODS: During the 21 months of the study, all patients who came to the medical emergency room of one single hospital as a result of chest pain or other symptoms suggestive of acute myocardial infarction were prospectively followed for 1 year. RESULTS: A total of 5362 patients were admitted on 7157 occasions; men accounted for 55% of the admissions. The 1-year mortality rate was 11% for men compared with 10% for women. The women were older and had a higher prevalence of known congestive heart failure and hypertension, whereas the prevalence of previous myocardial infarction was higher in men. When correcting for the dissimilarities in age and history of cardiovascular diseases, male gender appeared as an independent predictor of death. Development of myocardial infarction occurred in 25% of the men and 16% of the women (P < 0.001) during 1 year. The symptoms that brought patients to the emergency room were interpreted as being caused by myocardial infarction or myocardial ischemia in 29% of men compared with 21% of women (P < 0.001). CONCLUSIONS: In a consecutive series of patients with chest pain or other symptoms suggesting acute myocardial infarction in the emergency room, male gender was an independent risk indicator for death during 1 year. This might be explained by a higher occurrence of coronary artery disease in men than in women in this patient population.     

Prediction of the need for intensive care in patients who come to the emergency departments with acute chest pain

BACKGROUND: Patients who come to the emergency department with chest pain are a heterogeneous group. Some have ischemic heart disease that may lead to serious complications, whereas others have minor disorders. We performed a study to identify clinical factors that predict which patients will have complications requiring intensive care. METHODS: We first studied 10,682 patients with acute chest pain at seven hospitals between 1984 and 1986 (derivation set) to identify potential clinical predictors of the development of major complications. We then validated these predictors in a separate set of 4676 patients at one hospital between 1990 and 1994 (validation set). RESULTS: In the derivation set of patients, we identified the following set of clinical features, which, if present in the emergency department, were associated with an increased risk of complications: ST-segment elevation or Q waves on the electrocardiogram thought to indicate acute myocardial infarction, other electrocardiographic changes indicating myocardial ischemia, low systolic blood pressure, pulmonary rales above the bases, or an exacerbation of known ischemic heart disease. On the basis of these criteria, the patients in the validation set were stratified into four groups, with the risk of major complications in the first 12 hours ranging from 0.15 to 8 percent. After 12 hours, the probability of a major complication could be updated on the basis of whether the patient had already had a complication of major severity, a complication of intermediate severity, or a myocardial infarction (independent relative risks, 18.9, 7.7 and 4.0, respectively, as compared with patients without prior complications or myocardial infarction). CONCLUSIONS: The risk of major complications in patients with acute chest pain can be estimated on the basis of the clinical presentation and new clinical observations made during the hospital course. These estimates of risk help in making rational decisions about the appropriate level of medical care for patients with acute chest pain.     

Rarity of colorectal adenomas in the African black population

CONTEXT: Early risk stratification of patients with myocardial infarction is critical to determine optimum treatment strategies and enhance outcomes, but knowledge of the prognostic importance of the initial electrocardiogram (ECG) is limited. OBJECTIVE: To assess the independent value of the initial ECG for short-term risk stratification after acute myocardial infarction. DESIGN: Retrospective analysis of the Global Utilization of Streptokinase and t-PA (alteplase) for Occluded Coronary Arteries (GUSTO-I) clinical trial database. SETTING: A total of 1081 hospitals in 15 countries. PATIENTS: From the 41 021 patients enrolled in the overall study, we selected those who presented within 6 hours of chest pain onset with ST-segment elevation and no confounding factors (paced rhythms, ventricular rhythms, or left bundle-branch block) on the ECG performed before thrombolysis was administered (n=34 166). MAIN OUTCOME MEASURE: Ability of initial ECG to predict all-cause mortality at 30 days. RESULTS: Most ECG variables were associated with 30-day mortality in a univariable analysis. In a multivariable analysis combining the initial ECG variables and clinical predictors of mortality, the sum of the absolute ST-segment deviation (both ST elevation and ST depression: odds ratio [OR], 1.53; 95% confidence interval [CI], 1.38-1.69), ECG, heart rate (OR, 1.49; 95% CI, 1.41-1.59), QRS duration (for anterior infarct: OR, 1.55; 95% CI, 1.43-1.68), and ECG evidence of prior infarction (for new inferior infarct: OR, 2.47; 95% CI, 2.02-3.00) were the strongest ECG predictors of mortality. A nomogram based on the multivariable model produced excellent discrimination of 30-day mortality (C-index, 0.830). CONCLUSIONS: In patients presenting with myocardial infarction accompanied by ST-segment elevation, components of the initial ECG help predict 30-day mortality. This information should be valuable in early risk stratification, when the opportunity to reduce mortality is greatest, and may help in assessing outcomes adjusted for patient risk.     

The effect of ischemic preconditioning on early death in acute Q-wave myocardial infarction

Ischaemic preconditioning is still a laboratory-based phenomenon, not conclusively documented in patients. In this study it was of interest whether there is any beneficial influence of ischemic preconditioning on 30-day in-hospital mortality in patients undergoing acute Q-wave myocardial infarction. All men and women admitted to our ward between December 1994 and July 1996 with their first acute Q-wave myocardial infarction were divided into two groups. I group--29 patients with prodromal angina, defined as chest pain episodes in the 24-hour period before myocardial infarction. II group--25 patients who showed no chest pain before infarction onset. Both groups did not differ statistically in view of age, sex, smoking habits and adjunctive therapy. The use of streptokinase in the I and II group was also similar--in 58.6% and 56% of patients respectively in the first and second group. In the I group there was no fatal outcome, all 5 death cases occurred in the II group. The results are statistically significant and suggest lower in-hospital mortality in Q-wave myocardial infarction patients with previous ischaemic preconditioning.     

Thallium-201 myocardial scintigraphy in patients with normal coronary arteries and normal left ventriculogram - comparison with hemodynamics, metabolic and morphologic findings (author's transl)

36 consecutive patients with chest pain and/or severe ventricular dysrhythmias, but normal coronary arteries and normal left ventriculogram, underwent thallium-201 myocardial imaging at rest and during exercise. The myocardial scintigram was abnormal in 27 patients (group A) and normal in only 9 patients patients (group B). To answer the question, whether the scintigram was false positive or a correct expression of a myocardial disorder not detectable with angiocardiographic methods, we compared the scintigraphic results with the findings of resting and exercise ECG (n = 36), mean pulmonary artery pressure during exercise (n = 27), myocardial lactate extraction during highrate atrial pacing (n = 14) and light- and electronmicropic examination of right ventricular endomyocardial biopsies (n = 14). The resting ECG was abnormal in 7 of 27 patients of group A and 1 of 9 patients of group B, the exercise ECG in 20 of 27 patients of group A and 1 of 9 patient B. An abnormally elevated exercise pulmonary artery pressure was measured in 10 of 21 patients of group A and 1 of 6 patients of group B. High rate atrial pacing induced an abnormal myocardial lactate extraction in 3 of 13 patients of group A, but not in the single investigated patient of group B. All 12 examined patients of group A and 1 of 2 patients of group B had abnormal biopsy findings. The high incidence of abnormal findings in group A compared to the rare incidence in group B suggests, that the abnormal myocardial scintigrams in patients with chest pain and normal coronary arteries is likely not false positive but reflects a myocardial disorder not being recognized on angiography.     

Beyond the twelve-lead electrocardiogram: diagnostic tests in the evaluation for suspected acute myocardial infarction in the emergency department, part I

On a daily basis the emergency physician is faced with the difficult task of determining whether or not a patient with acute chest pain is sustaining an acute myocardial infarction. In most cases, this is not a straightforward decision. Although observation units are being used more often for chest pain evaluations, many emergency physicians currently admit such patients to an intensive care setting. Because fewer than one-third of emergency department chest pain patients actually suffer an acute myocardial infarction, expensive resources are, in retrospect, used unnecessarily. Conversely, patients who are infarcting, and are inadvertently discharged home from the emergency department, have a worse prognosis than those admitted. This two-part series reviews the newer modalities available that may help the emergency physician arrive at a more accurate diagnosis. The current article, Part I, examines the use of myocardial imaging, computer assisted diagnostic protocols, and newer uses of the electrocardiogram. Part II reviews the use of biochemical assays of cardiac proteins and the Chest Pain Observation Unit.     

The "pedrada" ("coup-de-fouet") syndrome. A possibility to be considered in acute leg pain

The authors report the case of a woman admitted to hospital for minor trauma of the left hip and who presented major ST segment elevation on the second day suggesting an acute anterior wall myocardial infarction at the same time as a cerebrovascular accident. Complementary investigations and follow-up excluded the diagnosis of myocardial infarction with normalisation of the ECG on the 5th day. ECG changes during cerebrovascular accidents may be very variable ranging from extrasystoles to ST elevation mimicking myocardial infarction. They carry a poor prognosis with an increased risk of sudden death necessitating continuous ECG monitoring until the ECG reverts to normal. The cardiac involvement is not ischaemic but due to disease of the insular cortex of the brain which induces myocytolysis (centered around the intra-cardiac nerve endings) due to the sudden liberation of catecholamines. These lesions may be treated by propranolol or phentolamine.     

Diagnostic difficulties of myocardial infarct in an admissions and emergency service: influence of age

OBJECTIVE: To analyze the clinical signs and electrocardiographic and enzyme data in patients admitted to an emergency ward for myocardial infarction in order to highlight diagnostic pitfalls. PATIENTS AND METHODS: All patients admitted to our emergency ward between October 1995 and October 1996 with elevated myoglobulin or creatinine phosphokinase (CPK) levels (n = 457 patients) were included in the study series. Patient files were randomly selected (n = 257 files) for review by an emergency ward specialist and a cardiologist to identify cases of myocardial infarction (n = 88 patients, mean age 73.4 +/- 15.2 years). Clinical, electrical and enzyme data (including CPK-MB) were analyzed. RESULTS: The patients had been referred for chest pain (69%), dyspnea (24%) or another disorder (7%). Pain was located in the retrosternal area in 51%, in the lower chest in 19% and elsewhere in 30%. Delay between onset of pain and transfer to the emergency ward was 5 h 20 min +/- 6 h. Signs of left heart failure were observed in 50% of the patients. The admission electrocardiogram showed complete criteria for myocardial infarction in 43% of the cases, incomplete criteria in 21% and was non-contributive in 36%. Enzyme results were elevated in 78% of the cases at the first assay and in 98.2% at the second assay. Both typical chest pain and ECG were observed in only 30% of the cases. Chest pain was present in 55% of the patients over 75 years of age and in 81% of those under 75 years (p = 0.007). CONCLUSION: A typical syndrome is observed in less than one-third of all patients with myocardial infarction admitted to emergency wards. The frequency of atypical presentations increases with age.     

Sublabial, transseptal, transsphenoidal approach to the pituitary region guided by the ACUSTAR I system

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

ECG changes associated with spontaneous left-sided pneumothorax

A patient with chronic obstructive pulmonary disease had a 100% pneumothorax on the left side associated with marked ECG changes. The changes occurring in this situation can be confusing. Because of the high prevalence of coronary heart disease in patients presenting with left-sided chest pain, an ECG usually is obtained to rule out acute myocardial infarction, in many instances even before history taking, physical examination, or chest x-ray study is done. Therefore, familiarity with the ECG manifestations of left-sided penumothorax is necessary to avoid delay in establishing the diagnosis and in beginning therapy.