bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics of patients with abnormal stress technetium Tc 99m sestamibi SPECT studies without significant coronary artery diameter stenoses
Authors: Ammann Peter , Naegeli Barbara , Rickli Hans , Buchholz Susanne , Mury Raymond , Schuiki Ernst , Bertel Osmund 
Published: June 2007

AbstractBackground: Single‐photon emission computed tomography (SPECT) sestamibi (MIBI) is an excellent tool for detection of coronary artery disease (CAD), preoperative risk assessment, and follow‐up management after coronary revas‐cularization. While the sensitivity of MIBI SPECT for detecting CAD has been reported to exceed 90%, the specificity ranges between 53–100%.Hypothesis: The study was undertaken to assess characteristics of patients with abnormal stress technetium Tc 99m sestamibi SPECT (MIBI) studies without significant coronary artery diameter stenoses (< 50%).Methods: Between January 1999 and November 2000, 270 consecutive patients were referred for coronary angiography due to reversible MIBI uptake defects during exercise. In 41 patients (15%; 39% women, mean age 59 ± 9 years), reversible MIBI uptake defects were assessed although coronary angiography showed no significant CAD. These patients were compared with age‐ and gender‐matched patients with perfusion abnormalities (39% women, mean age 60 ± 9 years), due to significant CAD (coronary artery stenosis > 50%).Results: There were no significant differences between the two groups regarding body mass index, left bundle‐branch block (LBBB), or method of stress test (dipyridamole in patients with LBBB or physical inactivity [n= 11] and exercise in all the others [n= 30]). Left ventricular hypertrophy (44 vs. 23%, p = 0.05) and left anterior fascicularblock (LAFB) (17 vs. 0%, p = 0.005) were more common in patients with perfusion abnormalities with no significant CAD, whereas ST‐segment depression during exercise (17 vs. 37% p = 0.05) and angina during exercise (15 vs. 29%, p = 0.02) were significantly less common than in patients with abnormal MIBI perfusion studies and angiographically significant CAD. Sestamibi uptake defects during exercise were significantly smaller in patients without significant CAD than in matched controls with significant CAD (p < 0.0004).Conclusion: Of 270 consecutive patients, 41 (15%) referred to coronary angiography due to reversible MIBI uptake defects showed coronary artery stenoses <50%. Twenty‐six (10%) of these presented angiographically normal coronary arteries. The significantly higher proportion of left ventricular hypertrophy and LAFB in patients with reversible MIBI uptake defects without significant CAD suggest microvascular disease, angiographically underestimated CAD, and conduction abnormalities as underlying mechanisms.
Additive value of low‐dose dobutamine to technetium‐99m sestamibi‐gated single‐photon emission computed tomography for prediction of wall motion improvement in patients undergoing coronary artery bypass graft
Authors: Zafrir Nili , Arditi Alexander , Ben‐Gal Tuvia , Solodky Alejandro , Hassid Yosef , Sulkes Jaqueline , Battler Alexander 
Published: June 2007

AbstractBackground: The two most useful methods for myocardial viability assessment are perfusion imaging and dobutamine echocardiography.Hypothesis: The present study investigated the additive value of a new method, dobutamine technetium 99m (99mTc)‐sestamibi‐gated single‐photon emission computed tomography (SPECT), which combines these two modalities, to the prediction of wall motion improvement after revascularization.Methods: Fifty‐five consecutive patients with ischemic cardiomyopathy, who were referred for viability evaluation, underwent resting and dobutamine (dose, 5–10 μkg/kg/min) gated SPECT with 99mTc‐sestamibi. Of these patients, 36 underwent coronary artery bypass graft (CABG) within 1 month of the study and 32 had repeat resting gated SPECT within 1 year. Global and regional wall motion, wall thickness, and perfusion were simultaneously analyzed at rest and after dobutamine using the 20‐segment model; the sestamibi uptake and wall motion response to dobutamine of each segment were rated quantitatively. Based on these findings, the segments were categorized as normal, viable, or nonviable. The predictive values for wall motion improvement were assessed by perfusion, using cutoffs of 50 and 60% of sestamibi uptake, and thereafter by the addition of dobutamine response in the segments that were rated nonviable.Results: Of the 1,080 myocardial segments studied, 906 (84%) had abnormal wall motion and were analyzed for viability. Concordance between perfusion and wall motion response to dobutamine was 60% with the 50% cutoff of sestamibi uptake, and increased to 65% with the 60% sestamibi cutoff (p < 0.04). The respective predictive values of wall motion improvement using the 50 and 60% cutoff points were as follows: sensitivity 93 and 70%, respectively, (p<0.01); specificity 59 and 86% (p < 0.001), respectively; accuracy 77% for both. The addition of the wall motion response to dobutamine to the assessment of the nonviable segments by perfusion (60% cutoff) increased the sensitivity from 70 to 85% (p = 0.001) and the negative predictive value from 70 to 81% (p = 0.009); the positive predictive value remained high (86 vs. 82%). No additive value of wall motion response to dobutamine was demonstrated for nonviable segments by perfusion with a 50% cutoff.Conclusion: Dobutamine sestamibi‐gated SPECT is a feasible method for the analysis of myocardial perfusion, function, and contractile reserve of individual myocardial segments in patients with ischemic cardiomyopathy. Viability assessment based on a threshold of 60% uptake of sestamibi, with the addition of the wall motion response to dobutamine in the nonviable segments, seems to yield better predictive values for wall motion improvement after CABG.
Osborn waves in the electrocardiogram, hypothermia not due to exposure, and death due to diabetic ketoacidosis
Authors: Sheikh Abdul M. , Hurst J. Willis 
Published: June 2007

AbstractHypothermia usually occurs because a patient has been exposed to a cold environment; however, a number of nonenvironmental conditions may produce hypothermia. This report relates the clinical course of a patient whose hypothermia was due to severe diabetic ketoacidosis. In addition, we review the causes of hypothermia and Osborn waves beyond exposure to cold temperature. Hypothermia due to diabetic ketoacidosis is an uncommon complication of a common disease that carries with it clinically significant consequences. Accordingly, we believe that all clinicians should be aware of this potential complication of diabetic ketoacidosis and should be able to recognize the importance of the electrocardiogram in such patients.
Association of aortic valve sclerosis and coronary artery disease in patients with severe nonischemic mitral regurgitation
Authors: Rossi Andrea , Bertagnolli Gerald , Cicoira Mariantonietta , Golia Giorgio , Zanolla Luisa , Santini Francesco , Cemin Claudio , Ferrario Gabriele , Zardini Piero 
Published: June 2007

AbstractBackground: The presence of aortic valve sclerosis accounts for a higher rate of ischemic events and increased cardiovascular mortality. It may reflect coronary artery disease (CAD) because of a shared pathologic background.Hypothesis: We aimed to analyze whether the presence of aortic valve sclerosis might help in identifying patients with coronary atherosclerosis among those with severe nonischemic mitral regurgitation (MR), who undergo coronary angiography before surgery for screening, and not because of suspected ischemic heart disease.Methods: In all, 84 patients (mean age 64 ± 9 years; 71% men) with mitral valve prolapse and severe regurgitation underwent echocardiography and coronary angiography. Aortic valve sclerosis was defined as focal areas of increased echogenicity and thickening of the leaflets without restriction of leaflet motion on echocardiography. Coronary artery disease was defined by the presence/absence of atherosclerotic plaques, independent of the degree of stenosis.Results: Coronary artery disease was diagnosed in 47.6% of patients with and 15.8% of those without aortic valve sclerosis (p = 0.008). On logistic regression analysis, the presence of aortic valve sclerosis predicted CAD (odds ratio 3.3,95% confidence interval 1.03‐10.5; p = 0.04) independent of age. In female patients, the risk ratio for CAD in the presence of aortic valve sclerosis was 9.Conclusions: Coronary artery atherosclerosis and aortic valve sclerosis are closely associated in patients with severe nonischemic MR.
Optimizing adjunctive antithrombotic therapy in the treatment of acute myocardial infarction: A role for low‐molecular‐weight heparin
Authors: Brieger David 
Published: June 2007

AbstractThrombotic complications account for a large proportion of in‐hospital deaths from acute myocardial infarction (MI). Although thrombolytic therapy has greatly improved clinical outcomes following MI, thrombin released during clot lysis has a prothrombotic effect, and the thrombolytic agents themselves may directly activate platelets. Antithrombotic therapy as an adjunct to thrombolysis improves the speed and extent of artery recanalization and reduces the incidence of secondary ischemic complications. The current treatment standard is unfractionated heparin (UFH) administered intravenously for 24‐48 h. However, UFH has not been unequivocally shown to improve outcomes in large‐scale, randomized clinical trials, and shows no evidence of benefit when used as an adjunct to streptokinase‐based thrombolysis. Unfractionated heparin also has several clinical and practical disadvantages, such as the need for coagulation monitoring, difficulties attaining a stable and reliable anticoagulant effect, and the risk of hemorrhagic side effects. Low‐molecular‐weight heparin (LMWH) represents a safe and effective alternative antithrombotic therapy, with a stable and predictable anticoagulant effect, potential for use in combination with either fibrin‐specific or streptokinase‐based thrombolysis, no need for anticoagulation monitoring, and a low risk of hemorrhagic and other heparin‐related complications. Several randomized clinical trials have shown that adjunctive LMWH is at least as effective as UFH in the acute phase of MI, is associated with fewer in‐hospital recurrent ischemic events, and has an acceptable safety profile.
Marked low‐density lipoprotein cholesterol reduction below current national cholesterol education program targets provides the greatest reduction in carotid atherosclerosis
Authors: Kent Steven M. , Coyle Louis C. , Flaherty Patrick J. , Markwood Thor T. , Taylor Allen J. 
Published: June 2007

AbstractBackground: Current National Cholesterol Education Program (NCEP) guidelines recognize low‐density lipoprotein cholesterol (LDL‐C) below 100 mg/dl as an optimal level. Evidence supporting this is scant. Both LDL‐C and C reactive protein (CRP) are known correlates of atherosclerosis progression.Hypothesis: We examined the effect of final LDL‐C and CRP obtained with statin therapy on carotid intima‐media thickness (CIMT), a valid surrogate for clinical benefit of lipid‐lowering therapies.Methods: In a randomized, single‐center trial, 161 patients were assigned to statin therapy of different potencies (pravastatin 40 mg, n = 82; atorvastatin 80 mg, n=79). The effects on CIMT were assessed in relationship to LDL‐C and CRP levels obtained after 12 months of therapy.Results: Changes in CIMT were directly related to the final LDL‐C level obtained on statin therapy after 12 months (R = 0.219, p = 0.015). Carotid intima‐media thickness regression was seen in 61% of the subjects in the lowest quartile of final LDL‐C (≤ 70 mg/dl) versus 29% of the subjects with the highest quartile of final LDL‐C (≥ 114 mg/dl, p = 0.008). No threshold value was seen, with more favorable effects on absolute change in CIMT with lower values of LDL‐C (decrease in CIMT of 0.06 ±0.17 mm in the lowest quartile compared with an increase of 0.06 ± 0.09 in the highest quartile of LDL‐C, p = 0.008). On‐treatment LDL and CRP concentrations both below the group median values were associated with the greatest likelihood of CIMT regression.Conclusions: Regression of carotid atherosclerosis is directly related to the absolute LDL‐C level on statin therapy. The greatest regression was obtained with an LDL‐C <70 mg/dl, supporting marked LDL‐C reduction to levels below current NCEP guidelines.
Comparison of hemostatic activation created by right‐ and left‐heart radiofrequency catheter ablation
Authors: Charng Min‐Ji , Lin Yenn‐Jiang , Chiu Ting‐Yu , Cheng Chien‐Min , Ding Philip Yu‐An 
Published: June 2007

AbstractBackground: Thromboembolic complications commonly occur in radiofrequency (RF) ablation procedures (0.6‐1.3% of cases). Comparison of hemostatic activation between left and right RF ablation is limited.Hypothesis: The purpose of this study was to evaluate platelet and hemostatic activation before, immediately after, and 48 h following left and right myocardial RF ablation procedures.Methods: The subjects were two groups of patients who underwent right‐heart (24 patients) and left‐heart (20 patients) RF ablation. Blood samples taken before, immediately after, and 48 h after the procedure were tested for changes in platelet and hemostatic activation.Results: No indication of clinically symptomatic thrombo‐embolism and no major differences in baseline characteristics and procedure were apparent in either group, except for a higher temperature mode setting (p < 0.001) in the left‐heart group. The hemostatic evaluation levels increased significantly by the end of the procedure in both groups and the platelet activation level remained elevated for 48 h after the procedure. The platelet activation level increased insignificantly at the end and 48 h after the procedure. Of the other changes in levels of platelet and hemostatic activation, only an increase in one of the hemostatic levels in the right‐heart group at 48 h after procedure was significant (p = 0.01).Conclusions: Our findings suggest that similar hemostatic activation occurred during and immediately after RF ablation in both groups. Sustained elevation of the hemostatic marker after the ablation procedure in the right‐heart group was observed as of significant therapeutic and prognostic implications.
Do the right precordial leads during exercise testing contribute to detection of coronary artery disease?
Authors: Ueshima Kenji , Kobayashi Noboru , Kamata Junya , Saitoh Masahiko , Yamazaki Takuya , Chiba Ikuo , Hiramori Katsuhiko 
Published: June 2007

AbstractBackground: It is still unknown whether or not the additional right precordial leads (RPL) during exercise testing contribute to detection of coronary artery disease (CAD).Hypothesis: The aim of this study was to evaluate the RPL during exercise testing for the detection of CAD.Methods: The study included 157 consecutive patients (116 men and 41 women, mean age 66 years) suspected of having CAD, who underwent conclusive treadmill exercise testing (heart rate reached at least 85% of the predicted maximum or positive electrocardiogram [ECG] changes were exhibited) and coronary angiography. During exercise testing, the ECG was recorded with the standard 12 leads and 4 RPL (V3R, V4R, V5R, V6R).Results: Of the 157 patients, 67 had CAD (> 75% stenosis in at least one major coronary artery), and 64 had positive ST changes in the standard ECG leads during exercise testing. Using the conventional 12‐lead method, sensitivity and specificity were 76 and 86%, respectively. Only three patients exhibited positive changes in the RPL leads; all had > 0.1 mV ST elevation in one of the RPL leads with > 0.1 mV ST elevation in aVR. Two of these patients had significant right coronary artery lesions and the other had a lesion of the left anterior descending artery which perfused the inferior as well as the anteroseptal area. In the standard 12 leads, one of the patients with an abnormal RPL and a right coronary lesion was negative, while the other two patients were positive. Combining RPL with the conventional 12‐lead method, sensitivity and specificity were 78 and 86%, respectively. Therefore, RPL did not improve the accuracy of the exercise ECG.Conclusion: The use of RPL during exercise testing may contribute to the detection of ischemia perfused by the right coronary artery; however, it does not improve the diagnostic accuracy of the exercise test.
A perspective on rate control in the treatment of atrial fibrillation
Authors: Waldo Albert L. 
Published: June 2007

AbstractUntil recently, the standard approach to therapy of atrial fibrillation (AF) in most cases was restoration and maintenance of sinus rhythm (rhythm control). Although difficult to accomplish, and associated with potential serious adverse effects of antiarrhythmic agents, this therapeutic approach was influenced by the belief that rhythm control was associated with better survival, fewer symptoms, better exercise tolerance, lower risk of stroke, better quality of life, and absence of need for long‐term anticoagulation. However, four clinical trials comparing rate control with rhythm control have failed to demonstrate these advantages, indicating that rate control should be considered a legitimate primary therapeutic option, particularly in patients at risk for stroke. Pursuit of rate or rhythm control should be decided on a case‐by‐case basis.
Classification and risk stratification of patients with acute chest pain using a low discriminatory level of cardiac troponin T
Authors: Solymoss B. Charles , Bourassa Martial G. , Cernacek Peter , Fortier Annik , Théroux Pierre 
Published: June 2007

AbstractBackground: Cardiac troponins are the biochemical markers of choice for the evaluation of acute coronary syndromes (ACS). Using the first‐generation test, most studies related adverse outcome to > 0.20 or 0.10 μg/l cardiac troponin T (cTnT) levels. With the highly sensitive and specific second‐ and third‐generation assays, cTnT is undetectable in most healthy individuals.Hypothesis: We evaluated whether a lower cTnT level, within 24 h of admission, could indicate an increased risk of future complications.Methods: During 1998–1999, clinical data were collected in 260 patients with ACS. Cardiac troponin T was measured at arrival, and 4, 8, and 12–24 h thereafter. The maximum cTnT value was then used to assess, over a 15‐month follow‐up period, the cumulative risk of death or myocardial infarction (MI), as well as rates of events according to quartiles of cTnT values.Results: Patients with ≤ 0.03 μg/l cTnT levels had the lowest rate of adverse events and the best Kaplan‐Meier event‐free survival curve. Increasing cTnT levels were associated with stepwise increases in mortality rates and with a constant 10fold increase in MI rates during follow‐up.Conclusions: A low threshold cTnT elevation is recommended to assess the risk of ACS. All cTnT elevations > 0.03 μg/l predict a higher risk of MI during follow‐up, whereas increasing values predict mortality in relation to the amount of elevation.
Peripheral arterial tonometry: A diagnostic method for detection of myocardial ischemia induced during mental stress tests: A pilot study
Authors: Goor Daniel A. , Sheffy Jacob , Schnall Robert P. , Arditti Alexander , Caspi Avraham , Bragdon Edith E. , Sheps David S. 
Published: June 2007

AbstractBackground: Mental stress testing is considered a reliable method for diagnosing patients with coronary heart disease (CHD) who may be at risk for future events. It has been shown recently that myocardial ischemia induced during mental stress tests is speciFICAlly associated with peripheral arterial vasoconstriction.Hypothesis: The study was undertaken to test the diagnostic capability of peripheral arterial tonometry (PAT) to detect peripheral arterial vasomotor changes.Methods: We monitored pulsatile finger blood volume changes using a specially designed finger plethysmograph, PAT that can detect peripheral arterial vasomotor changes. Equilibrium radionuclide angiography (ERNA) was simultaneously performed in 18 male patients at rest and during a mental arithmetic stress test with harassment. All patients had previously diagnosed coronary disease and positive exercise tests. Myocardial ischemia was diagnosed by ERNA when global ejection fraction fell ≥ 8% during mental stress or new (or worsened) focal wall motion abnormalities occurred. Peripheral arterial tonometry tracings were considered abnormal when the pulse wave amplitude decreased by ≥ 20% from baseline.Results: In 18 patients there were 16 usable studies. In eight patients, both ERNA and PAT were abnormal, and in six patients the tests were negative by both methods. In two cases, the results were discordant. Therefore, when considering an abnormal PAT tracing as indicative of mental stress‐driven myocardial ischemia, concordance of the two methods was 88%.Conclusion: The use of PAT may facilitate both clinical testing and research during mental stress.
Myoglobin—A marker of reperfusion and a prognostic indicator in patients with acute myocardial infarction
Authors: Iqbal M. Perwaiz , Kazmi Khawar A. , Mehboobali Naseema , Rahbar Abdul 
Published: June 2007

AbstractBackground: Early noninvasive identiFICAtion of patients with occluded infarct‐related arteries after thrombolysis has important prognostic and therapeutic implications. Recent reports indicate that plasma kinetics of cardiac marker proteins could be very useful in diagnosis of myocardial reperfusion. Although angiographic assessment remains the ideal procedure for determining patency, it is expensive, invasive, not within the reach of most patients in developing countries, and the long‐term follow‐up data are still sparse.Hypothesis: The present study was undertaken to investigate whether plasma kinetics of myoglobin in conjunction with clinical markers and another biochemical marker, creatine kinase, could be used to predict myocardial reperfusion more accurately and to investigate the correlation between myoglobin release after thrombolysis and mortality in patients with acute myocardial infarction (AMI) over a follow‐up period of 18 months.Methods: Eighty‐three consecutive patients with AMI receiving streptokinase treatment were studied for plasma kinetics of myoglobin in conjunction with clinical markers and creatine kinase to predict reperfusion and were followed for a period of 18 months.Results: Increased baseline mean ± standard deviation levels of myoglobin were observed among “nonresponders” to streptokinase treatment compared with “responders” (469 ± 386 μg/l vs. 270 ± 211 μg/l). There was signiFICAntly more release of myoglobin following thrombolytic treatment among the responders than among the nonresponders (mean ratio of myoglobin levels at 90 min to 0 min 6.01 ± 9.2 vs. 1.03 ± 0.64). In a follow‐up of 61 patients over a period of 18 months, 31% mortality was observed in the nonresponder group compared with 11.7% in the responder group. In responders, the mean ratio of myoglobin levels at 90 and 0 min was signiFICAntly less among those who died (p = 0.019) than among those who survived.Conclusion: A myoglobin release profile in combination with other clinical markers offers inexpensive, noninvasive, and a reasonably reliable way of assessing coronary artery patency after thrombolytic treatment.