Normal ECG Findings Research Articles

Accelerated diagnostic protocol using high-sensitivity cardiac troponin T in acute chest pain patients

BackgroundWe aimed to evaluate the efficacy and safety of using high-sensitivity cardiac troponin T (hs-cTnT) within an accelerated diagnostic protocol (ADP) in patients presenting with symptoms suggestive of acute myocardial infarction (AMI) for rapid rule-out of AMI. MethodsIn two independent large multicenter studies, levels of hs-cTnT at presentation and at 2h were combined with the Thrombolysis In Myocardial Infarction (TIMI) risk score and ECG findings. The ADP defined patients with normal levels of hs-cTnT at presentation and 2h, a TIMI score ≤1, and normal ECG findings as candidates for rapid rule-out of AMI and rapid discharge. Major adverse cardiac events (MACEs) occurring within 30-days were centrally adjudicated by two independent cardiologists. ResultsIn the derivation cohort, among 1085 consecutive patients 198 patients (18.2%) had a MACE. The ADP classified 374 patients (34.5%) as low-risk. None of these patients had a MACE at 30days, resulting in a negative predictive value (NPV) of 100% (95% CI, 99.0–100%) and a sensitivity of 100% (95% CI, 98.2%–100%). In the validation cohort, among 1590 consecutive patients 231 patients (14.5%) had a MACE. The ADP classified 641 patients (40.3%) as low-risk. 6 of these patients had a MACE at 30days, resulting in a NPV of 99.1% (95% CI, 98.0–99.6%) and a sensitivity of 97.4% (95% CI, 94.5–98.8%). ConclusionsThe ADP including hs-cTnT allows early identification 35 to 40% of patients to be at extremely low risk of MACE and therefore ideal candidates for outpatient management.

Values of high sensitive troponin T in long-term survivors of childhood cancer treated with anthracyclines

BackgroundCardiac biomarkers can play an important role in the early detection of subclinical heart failure. Our aims are to 1) obtain values of high sensitive cardiac troponin T (hs-cTnT) in long-term survivors of childhood cancer and 2) investigate the potential role of hs-cTnT in the detection of subclinical late-onset cardiotoxicity. MethodsHs-cTnT and N-terminal-pro-brain natriuretic peptide (NT-pro-BNP) were measured in 64 survivors. Electrocardiography and echocardiography were performed to evaluate cardiac function. ResultsMean follow-up period was 8.3years (range of 4.5 to 34.1). All survivors were clinically asymptomatic and had no history of clinical heart failure during or immediately after anthracycline treatment. Electrocardiography (available in 59 of 64 survivors) showed no signs of myocardial injury related to ischemia or abnormal QTc. Echocardiography was performed in all survivors. Mean left ventricular shortening fraction (SF) was 34% (range of 28 to 43%); mean ejection fraction (EF) was 61% (range of 48 to 74%). Seven survivors had a mildly decreased EF between 48% and 55%. Normal hs-cTnT levels were found in all 64 survivors (range of 3 to 13ng/L) and did not differ among different anthracycline dosage groups: ≤120, 120–300 and ≥300mg/m2. Yet, 5/64 survivors had elevated NT-pro-BNP levels (range of 7 to 25pg/ml) with normal SF and ECG findings and only one mildly abnormal EF of 51%. ConclusionsHs-cTnT concentrations are normal in long-term survivors of childhood cancer, even in the subpopulations with elevated NT-pro-BNP and/or a mildly decreased EF, indicating that it is not a sensitive marker for late onset subclinical anthracycline induced cardiotoxicity.

Baja tasa de infarto cerebral, infarto de miocardio y muerte vascular con el diagnóstico y tratamiento etiológico rápido del ataque isquémico transitorio

IntroductionThe 90-day risk of cerebral infarction in patients with transient ischaemic attack (TIA) is estimated at between 8% and 20%. There is little consensus as to which diagnostic strategy is most effective. This study evaluates the benefits of early transthoracic echocardiography (TTE) with carotid and transcranial Doppler ultrasound in patients with TIA. MethodsProspective study of patients with TIA in an emergency department setting. Demographic data, vascular risk factors, and ABCD2 score were analysed. TIA aetiology was classified according to TOAST criteria. All patients underwent early vascular studies (<72hours), including TTE, carotid ultrasound, and transcranial Doppler. Primary endpoints were recurrence of stroke or TIA, myocardial infarction (MI), or vascular death during the first year. ResultsWe evaluated 92 patients enrolled over 24 months. Mean age was 68.3±13 years and 61% were male. The mean ABCD2 score was 3 points (≥5 in 30%). The distribution of TIA subtypes was as follows: 12% large-artery atherosclerosis; 30% cardioembolism; 10% small-vessel occlusion; 40% undetermined cause; and 8% rare causes. Findings from the early TTE led to a change in treatment strategy in 6 patients (6.5%) who displayed normal physical examination and ECG findings. At one year of follow-up, 3 patients had experienced stroke (3.2%) and 1 patient experienced MI (1%); no vascular deaths were identified. ConclusionsIn our TIA patients, early vascular study and detecting patients with silent cardiomyopathy may have contributed to the low rate of vascular disease recurrence.

The new Seattle Criteria reduce the prevalence of abnormal ECG findings in professional football players

Purpose: To compare the new "Seattle Criteria" for ECG interpretation in athletes, with former recommendations from ESC. Methods: In 2008, 574 professional football players (mean age 25, range 18-38 years) in Norway underwent preparticipation ECG-screening (CARDIOLINE, RealClick version 3.5.4., Milan, Italy). ECGs were read manually by one investigator, measuring the global QRST complex with calipers. Analyzes were performed according to the definitions of Corrado et al. 2010, as "updated" by Uberoi et al. 2011, and the new "Seattle criteria" by Drezner et al. 2013, and the results were compared. Results: Main differences are presented in Table 1. Altogether 111 (19%) players had abnormal ECG-findings according to the "Seattle Criteria", compared to 292 (51%) applying the former ESC recommendations (p<0.001). Table 1. Main differences in normal and abnormal ECG findings between ESC versus "Seattle criteria" in interpreting athletes' ECG *Except in Africans. NA, not applicable; TWI, T-wave inversion. Conclusions: The significant reduction of 32% abnormal ECG-findings applying the new "Seattle Criteria" versus the ESC's recommendations will probably reduce the need and costs of extended examinations after preparticipation ECG-screening of athletes.

Unusual Vasospastic Angina: A Documented Asymptomatic Spasm with Normal ECG-A Case Report and a Review of the Literature.

We report the case of a 53-years-old patient, known to have coronary artery disease, presenting with typical angina at rest with normal ECG and laboratory findings. His angina is relieved by sublingual nitroglycerin. He had undergone a cardiac catheterisation two weeks prior to his presentation for the same complaints. It showed nonsignificant coronary lesions. Another catheterisation was performed during his current admission. He developed coronary spasm during the procedure, still with no ECG changes. The spasm was reversed by administration of 2 mg of intracoronary isosorbide dinitrate. Variant (Prinzmetal's) angina was diagnosed in the absence of electrical ECG changes during pain episodes.

Prognostic Value of Electrocardiographic Findings in Hemodynamically Stable Patients With Acute Symptomatic Pulmonary Embolism

The aim of this study was to determine the prognostic value of electrocardiography in hemodynamically stable patients with a diagnosis of acute symptomatic pulmonary embolism (PE). This prospective study included all hemodynamically stable outpatients who were diagnosed with PE at a university hospital. The electrocardiographic abnormalities investigated were: a) sinus tachycardia (>100 beats/min); b) ST-segment or T-wave abnormalities; c) right bundle branch block; d) an S1Q3T3 pattern, and e) recent-onset atrial arrhythmia. The study included 644 patients. Overall, 5% of those with an ECG abnormality died due to PE in the 15 days after diagnosis compared with 2% of those with normal ECG findings (relative risk [RR]=2.4; 95% confidence interval [CI], 1-5,8; P=.05). Multivariate analysis showed that sinus tachycardia was associated with a 2.2-fold increased risk of death due to all causes in the month after PE diagnosis. After adjusting for age, a history of cancer, immobility, ECG abnormalities, and sinus tachycardia, the presence of recent-onset atrial arrhythmia was significantly associated with death due to PE in the first 15 days (RR=2.8; 95% CI, 1-8.3; P=.05). The negative predictive value of atrial arrhythmia for 15-day PE-related mortality was 97%, while the negative likelihood ratio was 0.79. In hemodynamically stable patients with acute symptomatic PE, the presence of sinus tachycardia and atrial arrhythmia were independent predictors of a poor prognosis. However, the usefulness of these factors for stratifying risk in PE patients is limited.

Midterm Outcome of Percutaneous Transcatheter Coil Occlusion of Coronary Artery Fistula

The mid- to long-term outcome of pediatric patients with coronary artery fistula (CAF) after transcatheter closure remains unknown. This study reports the midterm outcome of CAF closure by transcatheter Gianturco coil occlusion in pediatric patients. Eighteen patients with CAF confirmed by coronary angiography were seen in our institution. Among them, 4 patients who had persistent coronary artery dilatation received transcatheter Gianturco coil occlusion (age range, 25 months to 12 years; mean, 4.6 years). Two were closed with a single coil, and two were closed with two coils. No residual shunts were detected on follow-up angiography and echocardiography immediately after coil occlusion in all cases. Follow-up Doppler echocardiography (4/4) and angiography (3/4) showed persistent CAF occlusion in all 4 patients. Two of 3 patients with coexistent aneurysmal formation showed obliteration of the aneurysm on angiographic follow-up. In addition, 2 showed resumption of normal coronary arterial size, and 2 showed decrement of the coronary arterial diameter. All 4 patients had normal ECG findings after 26-83 months (mean, 49 months) of follow-up, and all were in NYHA functional class I. The midterm outcome of percutaneous transcatheter coil occlusion in the treatment of CAF is excellent.

Molecular Magnetic Resonance Imaging of Coronary Thrombosis and Pulmonary Emboli With a Novel Fibrin-Targeted Contrast Agent

The differential diagnosis of acute chest pain is challenging, especially in patients with normal ECG findings, and may include coronary thrombosis or pulmonary emboli. The aim of this study was to investigate the novel fibrin-specific contrast agent EP-2104R for molecular targeted MR imaging of coronary thrombosis and pulmonary emboli. Fresh clots were engineered ex vivo from human blood and delivered in the lungs and coronary arteries of 7 swine. Subsequent molecular MR imaging was performed with a navigator-gated free-breathing and cardiac-triggered 3D inversion-recovery black-blood gradient-echo sequence before and after systemic administration of 7.5 micromol/kg EP-2104R. Two swine served as the control group. MR images were analyzed by 2 investigators, and contrast-to-noise ratio and gadolinium concentration in the clots were assessed. Before contrast media application, no thrombi were visible. After contrast administration, all 32 pulmonary emboli, 3 emboli in the right heart, and 5 coronary thrombi were selectively visualized as white spots with a mean contrast-to-noise ratio of 32+/-19. The average gadolinium concentration from all 3 types of thrombi was 144+/-79 micromol/L. Molecular MR imaging with the fibrin-targeted contrast-agent EP-2104R allows selective visualization of acute coronary, cardiac, and pulmonary thrombi.

A case of Brugada syndrome observed in the normal ECG findings just before ventricular fibrillation

A case of Brugada syndrome observed in the normal ECG findings just before ventricular fibrillation

Chest pain after recent stress test: Is there a warranty?

Study objectives: Emergency physicians often incorporate recent stress test results into their decisionmaking process for the evaluation and disposition of chest pain patients, which is based on studies of prognosis after stress testing. However, the subset of patients who present to an emergency department (ED) with chest pain and a history of a normal stress test is not adequately addressed in the literature. We seek to determine whether a history of a recent normal stress test result in patients presenting with chest pain to the ED is associated with a low risk (<1%) of major acute cardiac events. Methods: Patients presenting to our ED with a chief complaint of chest discomfort between January 1, 1998, and September 30, 2002, and who had undergone a stress test at our institution within 2 years were included. The primary endpoint was acute myocardial infarction on ED visit or death within 30 days. The diagnosis of acute myocardial infarction was based on cardiac marker elevation or ECG. All ECGs were reread for the purpose of this study by an investigator blinded to all other clinical data. Previous stress tests included treadmill studies without imaging, treadmill studies with imaging, and pharmacologic imaging studies. Treadmill study results were considered normal if there were no ST-segment changes and no abnormalities of functional capacity or heart rate dynamics during or after exercise. Imaging study results were considered normal if there was no evidence of myocardial ischemia or scar. Results: There were 1,857 eligible patients, of whom 283 had treadmill tests without imaging (79 or 27% were normal), 750 had treadmill tests with imaging (235 or 31% were normal), and 824 had pharmacologic tests (448 or 54% were normal). There were 190 patients (10%) who had the primary endpoint; only 2 patients died within 30 days. The history of a normal stress test was associated with a lower risk of the primary endpoint (50/762 or 7% versus 140/1095 or 13%, odds ratio 0.48, 95% confidence interval [CI] 0.34 to 0.67, <i>P</i><.0001). Among 449 patients who had a normal stress test result and on initial presentation had a nondiagnostic ECG and normal biomarkers, only 9 (2.0%, 95% CI 1.1% to 3.8%) had the primary endpoint. Among 508 patients who, on initial presentation, had a nondiagnostic ECG and normal biomarkers but had a history of an abnormal stress test result, 16 (3.2%, 95% CI 2.0% to 5.1%) had the primary endpoint. Conclusion: Among patients presenting with chest pain to the ED and a history of stress testing within the past 2 years, a normal stress test result was associated with a markedly reduced risk of having a major cardiac endpoint. However, with the possible exception of patients presenting with initially normal biomarkers and ECG findings, the absolute risk of 7% was not reassuringly low enough to justify early discharge.

Reference ranges for natriuretic peptides for diagnostic use are dependent on age, gender and heart rate.

Plasma natriuretic peptide levels may be useful in the diagnosis of heart failure. The available natriuretic peptide assays differ markedly in their performance characteristics. In addition, plasma levels are influenced by a number of factors including age and gender. The aim of this study was to describe, in a healthy population, the influence of clinical and echocardiographic parameters on three natriuretic peptide moieties. 1360 individuals were screened for the presence of left ventricular systolic dysfunction. We identified a cohort (n=720) of men aged 45-80 years (n=417) and women aged 55-80 years (n=303). None had history of cardiovascular disease or were taking any cardiovascular medication. All had normal echocardiographic and ECG findings. B-type (BNP), N-terminal pro-B-type (N-BNP) and N-terminal pro-Atrial (N-ANP) natriuretic peptides were assayed using in-house immunoluminometric assays. Of the considered clinical variables, only gender and heart rate (each P<0.005) were independently associated with levels of all three natriuretic peptides. Plasma levels of N-ANP (15%), BNP (25%) and N-BNP (75%) were higher in women compared to men. An increase in heart rate of 10 bpm corresponded to a reduction of 9% in N-ANP or BNP and a 15% reduction in N-BNP. Each 10 years of age was associated with 16% and 74% increase in ANP and N-BNP levels, respectively, but no increase in plasma BNP. Left ventricular ejection fraction could be assessed in 582 (81%) subjects and correlated positively with N-ANP (r(s)=6.48x10(-3), P<0.001) and BNP (r(s)=2.4x10(-2), P<0.001) but not N-BNP (P=0.405). No parameter of diastolic function was associated with any peptide level. In this healthy population, plasma levels of N-ANP, BNP and N-BNP were variably influenced by clinical covariates. While all three peptides were higher in women, only N-ANP and N-BNP were influenced by age. Levels of all peptides were inversely correlated with heart rate. Using this immunoluminometric assay, plasma BNP is not influenced by age, in contrast to N-ANP and N-BNP. In constructing normal ranges for diagnostic use, covariates such as age and gender must be considered, in addition to the format of assay being used.

Right Apical Opacification on a Chest Radiograph and Chest Pain

A 55-year-old man presented to the hospital on several occasions with “atypical” chest pain sometimes consistent with angina, with normal ECG findings and cardiac enzyme levels. The only risk factor for ischemic heart disease was smoking 10 to 20 cigarettes a day. His medical history included hematuria, with normal IV urogram and cystoscopic findings. He was unable to perform an exercise test due to severe diffuse “arthritis” (previous radiographic confirmation of lumbar and cervical osteoarthritis), and results of a subsequent dipyridamole myocardial perfusion scan suggested mild ischemic heart disease.

Is Telemetry Monitoring Necessary in Low-Risk Suspected Acute Chest Pain Syndromes?

Non-ICU telemetry monitoring has proven to be a valuable resource for patients suspected of having an acute myocardial infarction. While a significant number of patients are admitted to these units, the actual incidence of events or interventions is low. To identify a subset of patients in whom telemetry monitoring does not alter management. Prospective observational study. Large tertiary care facility. A total of 414 patients consecutively admitted from the emergency department for suspected acute coronary syndromes were studied. Patients were excluded if they presented with ST-segment elevations, were revascularized on hospital admission, were admitted to a surgical service, were transferred from another floor or unit, or remained in the emergency department for the course of the stay. Events were defined as development of myocardial infarction, episodes of chest pain, new or rapid atrial arrhythmias, ventricular arrhythmias, any form of AV nodal block, and asystole. Intervention or change in management was any increase, decrease, or change in medication, cardioversion, electrophysiology study, or transfer to the ICU. Patients who had atypical chest pain and normal ECG findings were significantly less likely to have both intervention and events (4 interventions vs 23 interventions [p < 0.0001], 12 events vs 45 events [p < 0.0001]), compared to those with typical chest pain and abnormal ECG findings. When normal laboratory values were added, only four telemetry events were observed. Patients with atypical chest pain and normal ECG findings represent a subset of patients with low risk for life-threatening arrhythmia. Use of telemetry monitoring in this subset of patients should be reevaluated.

Point-of-care testing of cardiac markers: results from an experience in an Emergency Department

Aim: An experimental approach to the use of point-of-care testing for cardiac markers in the Emergency Department (ED) of our Institution has been carried out using two devices (SCS, Dade Behring and Triage Cardiac Panel, Biosite Diagnostics) for the measurement of cardiac markers. Results: (1) From the analytical point of view, a fundamental tool for an efficient management of patients was the agreement between results from point-of-care testing and from the instruments located in STAT lab and/or central laboratory: in about 5% of patients, a lack of comparability of data, resulted in an inappropriate admission of patients (medical vs. intensive care unit). (2) The actual total turnaround time (TAT) in the management of samples sent to STAT lab was estimated to be equal to 82.5 min (50th percentile). (3) In the same organizational setting, the use of a point-of-care device produced a turnaround time equal to 17 min (50th percentile). (4) The reduction in turnaround time resulted in a faster discharge for five patients who had normal ECG findings and cardiac marker values, the Δ time (POCT-STAT lab) ranging from −10 to −70 min. Conclusions: The point-of-care option evaluated also in relation to personnel issues for staff working in the ED, brought some interesting questions about the characteristics of POCT devices (easy to use 100%, safety for operator 91%) and the obtained results (quantitative and correlated to STAT lab, 91%), as well as the need of other options such as the implementation of rapid tube sample delivery.

Use of Electron-Beam Computed Tomography in the Evaluation of Chest Pain Patients in the Emergency Department

Study objective: We sought to determine whether electron-beam computed tomography (EBCT) could be used as a triage tool in the emergency department for patients with angina-like chest pain, no known history of coronary disease, normal or indeterminate ECG findings, and normal initial cardiac enzyme concentrations. Methods: We conducted a prospective observational study of 105 patients admitted between December 1995 and October 1997 to the ED of a large tertiary care hospital with 70,000 annual ED visits. The study group was comprised of women aged 40 to 65 years and men aged 30 to 55 years who presented with angina-like chest pain requiring admission to the hospital or chest pain observation unit. All patients underwent EBCT of the coronary arteries, along with other cardiac testing as deemed necessary by staff physicians. Results: Of the 105 patients, 100 underwent other cardiac testing during hospitalization. Evaluation included treadmill exercise testing in 58, coronary angiography in 25, radionuclide stress testing in 19, and echocardiography in 11. Results of EBCT and cardiac testing were negative for both in 53 patients (53%), positive for both in 14 (14%), positive for tomography and negative for cardiac testing in 32 (32%), and negative for tomography and positive for cardiac testing in only 1 patient. This positive test result, on a treadmill exercise test, was ruled a false positive by an independent staff cardiologist. Two other female patients with normal exercise sestamibi or coronary angiography and EBCT findings also had false-positive treadmill exercise results. The sensitivity of EBCT was 100% (95% confidence interval, 77% to 100%), with a negative predictive value of 100% (95% confidence interval, 94% to 100%). Specificity was 63% (95% confidence interval, 54% to 75%). Conclusion: EBCT is a rapid and efficient screening tool for patients admitted to the ED with angina-like chest pain, normal cardiac enzyme concentrations, indeterminate ECG findings, and no history of coronary artery disease. Our study suggests that patients with normal initial cardiac enzyme concentrations, normal or indeterminate ECG findings, and negative results on EBCT may be safely discharged from the ED without further testing or observation. Larger studies are required to confirm this conclusion. [Laudon DA, Vukov LF, Breen JF, Rumberger JA, Wollan PC, Sheedy PF II: Use of electron-beam computed tomography in the evaluation of chest pain patients in the emergency department. Ann Emerg Med January 1999;33:15-21.]

Effect of Duration From Symptom Onset on the Negative Predictive Value of a Normal ECG for Exclusion of Acute Myocardial Infarction

Study objective: We hypothesized that the negative predictive value of the ECG would improve with time and assessed the effect of time elapsed from symptom onset to ED presentation on the negative predictive value, sensitivity, specificity, and positive predictive value of the initial ECG in patients presenting with symptoms suggestive of acute myocardial infarction (AMI). Methods: We conducted a cross-sectional study in a university teaching hospital. Our structured data instrument, completed at the time of presentation included demographics, time of onset of symptoms, history, laboratory, and ECG findings. AMI was diagnosed with the use of international diagnostic criteria. Patients were stratified according to duration of time from symptom onset at 3-hour intervals. Results: We enrolled 526 patients in the study group. The mean age was 59 years; 40% were female. The mean time elapsed from symptom onset to presentation was 185 minutes. A diagnosis of AMI was made in 104 patients (20%). The negative predictive values of a normal ECG for exclusion of AMI, stratified by duration of time from symptom onset, were: 0 to 3 hours, 93.2% (95% confidence interval [CI], 87.4% to 96.1%); 3 to 6 hours, 93.0% (95% CI, 83.0% to 98.1%); 6 to 9 hours, 92.6% (95% CI, 75.8% to 99.1%); and 9 to 12 hours, 94.1% (95% CI, 71.3% to 99.9%) ( P=1.0). The sensitivity, specificity, and positive predictive value of the ECG were similar in all groups. Conclusion: The negative predictive value of a normal ECG for exclusion of AMI does not improve as the duration of time from symptom onset to presentation increases. Normal ECG findings cannot be used to rule out an AMI, even those obtained up to 12 hours after symptom onset. [Singer AJ, Brogan GX, Valentine SM, McCuskey C, Khan S, Hollander JE: Effect of duration from symptom onset on the negative predictive value of a normal ECG for exclusion of acute myocardial infarction. Ann Emerg Med May 1997; 29:575-579.]

64-Year-Old Woman With Chest Pain and Presyncope

64-Year-Old Woman With Chest Pain and Presyncope

Wed 1030 The efficacy of droperidol utilization in air medical transport

Study objective: We sought to determine whether electron-beam computed tomography (EBCT) could be used as a triage tool in the emergency department for patients with angina-like chest pain, no known history of coronary disease, normal or indeterminate ECG findings, and normal initial cardiac enzyme concentrations. Methods: We conducted a prospective observational study of 105 patients admitted between December 1995 and October 1997 to the ED of a large tertiary care hospital with 70,000 annual ED visits. The study group was comprised of women aged 40 to 65 years and men aged 30 to 55 years who presented with angina-like chest pain requiring admission to the hospital or chest pain observation unit. All patients underwent EBCT of the coronary arteries, along with other cardiac testing as deemed necessary by staff physicians. Results: Of the 105 patients, 100 underwent other cardiac testing during hospitalization. Evaluation included treadmill exercise testing in 58, coronary angiography in 25, radionuclide stress testing in 19, and echocardiography in 11. Results of EBCT and cardiac testing were negative for both in 53 patients (53%), positive for both in 14 (14%), positive for tomography and negative for cardiac testing in 32 (32%), and negative for tomography and positive for cardiac testing in only 1 patient. This positive test result, on a treadmill exercise test, was ruled a false positive by an independent staff cardiologist. Two other female patients with normal exercise sestamibi or coronary angiography and EBCT findings also had false-positive treadmill exercise results. The sensitivity of EBCT was 100% (95% confidence interval, 77% to 100%), with a negative predictive value of 100% (95% confidence interval, 94% to 100%). Specificity was 63% (95% confidence interval, 54% to 75%). Conclusion: EBCT is a rapid and efficient screening tool for patients admitted to the ED with angina-like chest pain, normal cardiac enzyme concentrations, indeterminate ECG findings, and no history of coronary artery disease. Our study suggests that patients with normal initial cardiac enzyme concentrations, normal or indeterminate ECG findings, and negative results on EBCT may be safely discharged from the ED without further testing or observation. Larger studies are required to confirm this conclusion.[Laudon DA, Vukov LF, Breen JF, Rumberger JA, Wollan PC, Sheedy PF II: Use of electron-beam computed tomography in the evaluation of chest pain patients in the emergency department. Ann Emerg Med January 1999;33:15-21.]

Congenital Pulmonary Arteriovenous Fistula: A Rare Cause of Cyanosis in Childhood

Two children (both females) aged 15 months and 4 years are described as very rare cases of central cyanosis in childhood being caused by a congenital pulmonary arteriovenous fistula. The initial diagnosis was made based on cyanosis and chest radiographs, with normal physical, ECG, and radiological findings of the heart. They had no family history of the Rendu-Weber-Osler syndrome. The patients underwent cardiac catheterization and pulmonary angiography, where the diagnosis was confirmed. After the surgery, both were symptom-free, and had no evidence of the disease.

LEFT BUNDLE BRANCH BLOCK IN PREINDUCTION PERIOD OF ANESTHESIA

We has experienced a case who had normal preoperative ECG findings, however, developed a left bundle branch block (LBBB) in preinduction period of anesthesia. A 73-year-old male, with chief complaint of melena, was diagnosed as cancer of the sigmoid colon. He had no remarkable medical history nor abnormalities in preoperative laboratory findings. After entering the operating room to undergo elective resection of the sigmoid colon, lead II ECG tracing prior to mesthesia induction revealed a LBBB. However, it changed to normal sinus rhythm snddenly during our investigation of the cause. Following preoxygenation, anesthesia was induced with thiopental, intubated with succinylcholine, and maintained with nitrous oxide 66 percent in oxygen and halothane. During operation, a LBBB pattern occurred whenever heart rate increased to over 110 per minutes (rate dependent LBBB). No change in blood pressure was accompanied by these episodes.Recovery from anesthesia was uneventful. Post operative holter ECG showed intermittent LBBB with no change in GOT, GPT, CPK etc. Though LBBB itself is a relatively benign dysrhythmia, it is significant during anesthesia, because it may indicate a possible development of myocardial infarction. It is difficult to diagnose myocardial infarction on the ECG in the presence of a LBBB.