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ST Depression (st + depression)
Selected AbstractsDobutamine stress surface mapping of myocardial ischemia in Kawasaki diseasePEDIATRICS INTERNATIONAL, Issue 3 2001Nobuyuki Takechi Abstract Background: To detect and localize myocardial ischemia, a method that does not require physical exertion is sometimes needed in children with Kawasaki disease. Methods: Dobutamine stress body surface mapping was performed in 115 children with a history of Kawasaki disease (58 without coronary artery lesions, 40 who had coronary lesions without myocardial ischemia and 17 with myocardial ischemia). The maximum infusion rate of dobutamine was 30 ,g/kg per min. Myocardial ischemia was diagnosed by the presence of an area of hypoperfusion on scintigraphy at rest and/or an increase in hypoperfusion during a dobutamine stress test compared with resting scintigraphy. We studied the number of leads that showed significant ST depression on the isopotential map (nST), the number of the row containing the lead with the smallest negative value on the isointegral map (Imin), and the localization of myocardial ischemia on the isointegral map. Based on findings in patients without coronary artery lesions, we defined the criteria for detecting myocardial ischemia as nST , 1 and Imin, 4. Results: The sensitivity of detecting myocardial ischemia was 94.1% using nST and 41.7% using Imin, while the specificity of these methods was 98.9 and 96.9%, respectively. The localization of myocardial ischemia on stress body surface mapping was 100% concordant with that determined by stress myocardial scintigraphy. Conclusions: Dobutamine stress body surface mapping for the detection of myocardial ischemia is a non-invasive, more convenient and repeatable test compared with exercise myocardial scintigraphy and it is a more objective test compared with exercise echocardiography. Dobutamine stress body surface mapping is useful for the identification and localization of silent myocardial ischemia in pediatric patients with Kawasaki disease, especially those who cannot perform tests involving physical exercise. [source] Electrocardiographic Differentiation between Acute Pulmonary Embolism and Non-ST Elevation Acute Coronary Syndromes at the BedsideANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2010Krzysztof Jankowski M.D., Ph.D. Background: Clinical picture of acute pulmonary embolism (APE), with wide range of electrocardiographic (ECG) abnormalities can mimic acute coronary syndromes. Objectives: Assessment of standard 12-lead ECG usefulness in differentiation at the bedside between APE and non-ST elevation acute coronary syndrome (NSTE-ACS). Methods: Retrospective analysis of 143 patients: 98 consecutive patients (mean age 63.4 ± 19.4 year, 45 M) with APE and 45 consecutive patients (mean age 72.8 ± 10.8 year, 44 M) with NSTE-ACS. Standard ECGs recorded on admission were compared in separated groups. Results: Right bundle branch block (RBBB) and S1S2S3 or S1Q3T3 pattern were found in similar frequency in both groups (10 [11%] APE patients vs 6 [14%] NSTE-ACS patients, 27 [28%] patients vs 7 [16%] patients, respectively, NS). Negative T waves in leads V1-3 together with negative T waves in inferior wall leads II, III, aVF (OR 1.3 [1.14,1.68]) significantly indicated APE with a positive predictive value of 85% and specificity of 87%. However, counterclockwise axis rotation (OR 4.57 [2.74,7.61]), ventricular premature beats (OR 2.60 [1.60,4.19]), ST depression in leads V1-3 (OR 2.25 [1.43,3.56]), and negative T waves in leads V5-6 (OR 2.08 [1.31,3.29]) significantly predicted NSTE-ACS. Conclusions: RBBB, S1S2S3, or S1Q3T3 pattern described as characteristic for APE were not helpful in the differentiation between APE and NSTE-ACS in studied group. Coexistence of negative T waves in precordial leads V1-3 and inferior wall leads may suggest APE diagnosis. Ann Noninvasive Electrocardiol 2010;15(2):145,150 [source] Electrocardiographic Alterations during Hyperinsulinemic Hypoglycemia in Healthy SubjectsANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2008Tomi Laitinen M.D. Background: We evaluated the arrhythmogenic potential of hypoglycemia by studying electrocardiographic (ECG) changes in response to hyperinsulinemic hypoglycemia and associated sympathoadrenal counterregulatory responses in healthy subjects. Methods: The study population consisted of 18 subjects, aged 30,40 years. Five-minute ECG recordings and blood samplings were performed at baseline and during the euglycemic and hypoglycemic hyperinsulinemic clamp studies. PR, QT, and QTc intervals of electrocardiogram and ECG morphology were assessed from signal-averaged ECG. Results: Although cardiac beat interval remained unchanged, PR interval decreased (P < 0.01) and QTc interval (P < 0.001) increased in response to hyperinsulinemic hypoglycemia. Concomitant morphological alterations consisted of slight increases in R-wave amplitude and area (P < 0.01 for both), significant decreases in T-wave amplitude and area (P < 0.001 for both), and moderate ST depression (P < 0.001). Counterregulatory norepinephrine response correlated with amplification of the R wave (r =,0.620, P < 0.05) and epinephrine response correlated with flattening of the T wave (r =,0.508, P < 0.05). Conclusions: Hyperinsulinemic hypoglycemia with consequent sympathetic humoral activation is associated with several ECG alterations in atrioventricular conduction, ventricular depolarization, and ventricular repolarization. Such alterations in cardiac electrical function may be of importance in provoking severe arrhythmias and "dead-in-bed" syndrome in diabetic patients with unrecognized hypoglycemic episodes. [source] Observer Variability and Optimal Criteria of Transient Ischemia During ST Monitoring with Continuous 12-lead ECGANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2002Ph.D., Tomas Jernberg M.D. Background: ST monitoring with continuous 12-lead ECG is a well-established method in patients with unstable coronary artery disease (CAD). However, the method lacks documentation on optimal criteria for episodes of transient ischemia and on observer variability. Methods: Observer variability was evaluated in 24-hour recordings from 100 patients with unstable CAD with monitoring in the coronary care unit. Influence on ST changes by variations in body position were evaluated by monitoring 50 patients in different body positions. Different criteria of transient ischemia and their predictive importance were evaluated in 630 patients with unstable CAD who underwent 12 hours of monitoring and thereafter were followed for 1 to 13 months. Two sets of criteria were tested: (1) ST deviation , 0.1 mV for at least 1 minute, and (2) ST depression , 0.05 mV or elevation , 0.1 mV for at least 1 minute. Results: When the first set of criteria were used, the interobserver agreement was good (kappa = 0.72) and 8 (16%) had significant ST changes in at least one body position. Out of 100 patients with symptoms suggestive of unstable CAD and such ischemia, 24 (24%) had a cardiac event during follow-up. When the second set of criteria were used, the interobserver agreement was poor (kappa = 0.32) and 21(42%) had significant ST changes in at least one body position. Patients fulfilling the second but not the first set of criteria did not have a higher risk of cardiac event than those without transient ischemia (5.3 vs 4.3%). Conclusions: During 12-lead ECG monitoring, transient ischemic episodes should be defined as ST deviations , 0.1 mV for at least 1 minute, based on a low observer variability, minor problems with postural ST changes and an important predictive value. A.N.E. 2002;7(3):181,190 [source] Frequency of Acute Coronary Syndrome in Patients with Normal Electrocardiogram Performed during Presence or Absence of Chest PainACADEMIC EMERGENCY MEDICINE, Issue 6 2009Samuel D. Turnipseed MD Abstract Objectives:, The authors hypothesized that patients with active chest pain at the time of a normal electrocardiogram (ECG) have a lower frequency of acute coronary syndrome (ACS) than patients being evaluated for chest pain but with no active chest pain at the time of a normal ECG. The study objective was to describe the association between chest pain in patients with a normal ECG and the diagnosis of ACS. Methods:, This was a prospective observational study of emergency department (ED) patients with a chief complaint of chest pain and an initial normal ECG admitted to the hospital for chest pain evaluation over a 1-year period. Two groups were identified: patients with chest pain during the ECG and patients without chest pain during the ECG. Normal ECG criteria were as follow: 1) normal sinus rhythm with heart rate of 55,105 beats/min, 2) normal QRS interval and ST segment, and 3) normal T-wave morphology or T-wave flattening. "Normal" excludes pathologic Q waves, left ventricular hypertrophy, nonspecific ST-T wave abnormalities, any ST depression, and discrepancies in the axis between the T wave and the QRS. Patients' initial ED ECGs were interpreted as normal or abnormal by two emergency physicians (EPs); differences in interpretation were resolved by a cardiologist. ACS was defined as follows: 1) elevation and characteristic evolution of troponin I level, 2) coronary angiography demonstrating >70% stenosis in a major coronary artery, or 3) positive noninvasive cardiac stress test. Chi-square analysis was performed and odds ratios (ORs) are presented. Results:, A total of 1,741 patients were admitted with cardiopulmonary symptoms; 387 met study criteria. The study group comprised 199 males (51%) and 188 females (49%), mean age was 56 years (range, 25,90 years), and 106 (27%) had known coronary artery disease (CAD). A total of 261 (67%) patients experienced chest pain during ECG; 126 (33%) patients experienced no chest pain during ECG. There was no difference between the two groups in age, sex, cardiac risk factors, or known CAD. The frequency of ACS for the total study group was 17% (67/387). There was no difference in prevalence of ACS based on the presence or absence of chest pain (16% or 42/261 vs. 20% or 25/126; OR = 0.77, 95% confidence interval = 0.45 to 1.33, p = 0.4). Conclusions:, Contrary to our hypothesis concerning patients who presented to the ED with a chief complaint of chest pain, our study demonstrated no difference in the frequency of acute coronary syndrome between patients with chest pain at the time of acquisition of a normal electrocardiogram and those without chest pain during acquisition of a normal electrocardiogram. [source] Incremental Benefit of 80-Lead Electrocardiogram Body Surface Mapping Over the 12-Lead Electrocardiogram in the Detection of Acute Coronary Syndromes in Patients Without ST-elevation Myocardial Infarction: Results from the Optimal Cardiovascular Diagnostic Evaluation Enabling Faster Treatment of Myocardial Infarction (OCCULT MI) TrialACADEMIC EMERGENCY MEDICINE, Issue 9 2010Brian J. O'Neil MD ACADEMIC EMERGENCY MEDICINE 2010; 17:932,939 © 2010 by the Society for Academic Emergency Medicine Abstract Background:, The initial 12-lead (12L) electrocardiogram (ECG) has low sensitivity to detect myocardial infarction (MI) and acute coronary syndromes (ACS) in the emergency department (ED). Yet, early therapies in these patients have been shown to improve outcomes. Objectives:, The Optimal Cardiovascular Diagnostic Evaluation Enabling Faster Treatment of Myocardial Infarction (OCCULT-MI) trial was a multicenter trial comparing a novel 80-lead mapping system (80L) to standard 12L ECG in patients with chest pain and presumed ACS. This secondary analysis analyzed the incremental value of the 80L over the 12L in the detection of high-risk ECG abnormalities (ST-segment elevation or ST depression) in patients with MI and ACS, after eliminating all patients diagnosed with ST-elevation MI (STEMI) by 12L ECG. Methods:, Chest pain patients presenting to one of 12 academic EDs were diagnosed and treated according to the standard care of that site and its clinicians; the clinicians were blinded to 80L results. MI was defined by discharge diagnosis of non,ST-elevation MI (NSTEMI) or unstable angina (UA) with an elevated troponin. ACS was defined as discharge diagnosis of NSTEMI or UA with at least one positive test result (troponin, stress test, angiogram) or revascularization procedure. Results:, Of the 1,830 patients enrolled in the trial, 91 patients with physician-diagnosed STEMI and 225 patients with missing 80L or 12L data were eliminated from the analysis; no discharge diagnosis was available for one additional patient. Of the remaining 1,513 patients, 408 had ACS, 206 had MI, and one had missing status. The sensitivity of the 80L was significantly higher than that of the 12L for detecting MI (19.4% vs. 10.4%, p = 0.0014) and ACS (12.3% vs. 7.1%, p = 0.0025). Specificities remained high for both tests, but were somewhat lower for 80L than for 12L for detecting both MI and ACS. Negative and positive likelihood ratios (LR) were not statistically different between groups. In patients with severe disease (defined by stenosis > 70% at catheterization, percutaneous coronary intervention, coronary artery bypass graft, or death from any cause), the 80L had significantly higher sensitivity for detecting MI (with equivalent specificity), but not ACS. Conclusions: Among patients without ST elevation on the 12L ECG, the 80L body surface mapping technology detects more patients with MI or ACS than the 12L, while maintaining a high degree of specificity. [source] Cardiac dysfunction during exercise in patients with primary hyperparathyroidismBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 9 2000I.-L. Nilsson Background ,Non-traditional' manifestations of primary hyperparathyroidism (HPT) are controversial, and include morbidity, mortality and risk factors for cardiovascular diseases with some prospects of normalization by parathyroidectomy (PTX). This study evaluated previously unexplored data on cardiac function during exercise in HPT. Methods Thirty patients with HPT (mean(s.d.) serum calcium 2·96(0·24) mmol l,1) and 30 normocalcaemic controls (selected randomly from the background population, and matched for age and sex) underwent exercise testing, echocardiography and 24-h ambulatory blood pressure recordings before and a mean of 13 months after PTX. Results HPT was associated with higher systolic blood pressure during exercise (mean(s.d.) 223(28) versus 203(33) mmHg; P = 0·02), which correlated to the left ventricular (LV) mass and serum PTH (P = 0·014, P = 0·004); higher LV mass in men (mean(s.d.) 142(20) versus 113(28) g m,2), which might relate to the hypertrophic effect of PTH; and increased LV isovolumic relaxation times (mean(s.d.) 102(19) versus 91(15) ms; P = 0·018), indicating LV diastolic dysfunction. ST depression during exercise decreased significantly (mean(s.d.) , 1·0(0·9) versus 0·7(0·5) mm; P = 0·028) and LV mass declined in proportion with the time after PTX (P = 0·04 in men). PTX also affected systolic functions, as fractional shortening, atrioventricular plane displacement and systolic index decreased in men (P = 0·05, P = 0·04, P = 0·04). Twenty-four-hour blood pressures were higher in HPT (P = 0·008), when subjects on ,-blockers (seven patients, five controls) were excluded, and were unaltered by PTX. Conclusion LV systolic and diastolic dysfunction occurs in HPT. The diastolic dysfunction seems to diminish with time after PTX, while the positive inotropic effect of calcium in itself may alleviate the systolic dysfunction. © 2000 British Journal of Surgery Society Ltd [source] Myocardial Perfusion Profile in a Young Population With and Without Known Coronary Artery Disease: Comparison by GenderCLINICAL CARDIOLOGY, Issue 2 2010Nili Zafrir MD Background More and more young people are being referred for evaluation or screening for coronary artery disease (CAD). However, the value of myocardial perfusion imaging (MPI) in this population is unclear, especially in the absence of symptoms. Methods The study sample included 1765 consecutive patients less than 51 years old who were referred to a major medical center for stress/rest MPI study. Clinical and MPI variables were compared between patients with and without known CAD, by gender. Results There were 1346 (76%) men and 419 (24%) women of mean age 44 ± 6 years; 461 (26%) had known CAD. Stress-induced ischemia was detected in 321 patients (18.2%) and significant ischemia in 131 (7.4%); there was no difference in the rate or severity of ischemia by presence of symptoms. Among those without known CAD, the rate of stress-induced ischemia by MPI was significantly lower in women than men. On logistic regression analysis, the independent predictors of ischemia in men were high cholesterol, diabetes, angina during stress testing, ST depression, and smoking (P<.0001); and in women, the independent predictors were diabetes and high cholesterol. Conclusion Known CAD and stress-induced ischemia are significantly more prevalent in young men than in young women, irrespective of risk factors. The independent predictors of ischemia differ between men and women. Copyright © 2010 Wiley Periodicals, Inc. [source] Value of leads V4R and CM5 in the detection of coronary artery disease during exercise electrocardiographic testCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 4 2010Merja Puurtinen Summary The usefulness of the right precordial unipolar leads and the value of the bipolar lead CM5 in the detection of coronary artery disease (CAD) with exercise electrocardiographic (ECG) test are not well documented. The objective of this study was to evaluate the diagnostic performance of leads V4R and CM5. The study population comprised 579 patients referred for a bicycle exercise ECG test in the Finnish Cardiovascular Study. Patients were divided into three groups: angiographically proven CAD (CAD, n = 255), no CAD by angiography (NoCAD, n = 126), and low likelihood of CAD (LLC, n = 198). The maximum ST-segment depression at peak exercise was used as a parameter, and the diagnostic accuracy of different leads was assessed by receiver operating characteristic (ROC) analysis. Sensitivity and specificity values at a cut-off criterion of ,0·10 mV ST-segment, 1-mm ST depression, were determined. According to the results, incorporating lead V4R with the standard leads decreased the ROC area from 0·71 to 0·69 (comparison CAD versus LLC) and from 0·55 to 0·53 (comparison CAD versus NoCAD) and had no effect on sensitivity or specificity. Adding lead CM5 to the standard leads did not affect the ROC area but increased the sensitivity and decreased the specificity. In conclusion, the use of right precordial lead V4R along with the standard 12-lead system does not improve the performance of the exercise ECG in diagnosing CAD. Adding lead CM5 to the standard leads increases the sensitivity but does not change the overall diagnostic performance. [source] | ||||||||||