bluuebunny/crossref_metadata_2025_split huggingface dataset:
Angiographic and scintigraphic (perfusion and electrocardiogram‐gated spect) correlates of clinical presentation in unstable angina
Authors: Emre Ayşe , Ersek Birsen , Gürsürer METIN , Aksoy Mehmet , Siber Turgut , Engin Öuner , Yeşslilçlhvien Kemal 
Published: February 2009

AbstractBackground: Braunwald classification can be used as a measure of the acuteness or severity of clinical presentation of unstable angina. Gating perfusion images might provide additional information to that obtained from angiography, allowing correlations between the coronary anatomy and extent of myocardium at risk via simultaneous perfusion/function assessment.Hypothesis: The aim of this study was to determine the relation between the highest levels of the Braunwald classification (class III = rest angina within 48 h of presentation; class C = postinfarction angina; class c = refractory angina) and the angiographic findings, and the extent of perfusion and segmental wall motion abnormalities using technetium—99m ( 99m Tc) sestamibi‐gated single‐photon emission computed tomography (SPECT) imaging.Methods: The study group consisted of 86 patients with unstable angina who underwent rest gated 99mTc sestamibi SPECT imaging and coronary angiography. Perfusion was graded on a 5—point scale (0 = normal; 4 = absent uptake) and wall motion on a 4—point scale (0 = akinesia/dyskinesia; 3 = normal) using the 20 segment model. Perfusion (PI) and wall motion indices (WMI) were calculated by adding the score of all segments and dividing this by 20. The localization, the degree of stenosis, and the morphology of the culprit lesion were assessed. Multivariate analysis was performed to identify the independent predictors of class III, C, and c angina.Results: Perfusion index was higher and WMI was lower in classes HI, C, and c than in classes < III, < C, and < c, respectively (all p < 0.001). Class III angina was associated with PI (p < 0.0001), WMI (p < 0.0001), complex morphology (p = 0.01), and decreased Thrombolysis in Myocardial Infarction (TIMI) flow (p = 0.002); class C angina with PI (p< 0.0001), WMI (p<0.0001), intracoronary thrombus (p = 0.007), and decreased TIMI flow (p = 0.003); and class c angina with PI (p = 0.005) and WMI (p = 0.006).Conclusion: The highest levels of the Braunwald classification are associated with a greater size and intensity of myocardial perfusion and wall motion abnormalities and with the angiographic findings of complex morphology, intracoronary thrombus, and decreased TIMI flow.
Intravascular ultrasound predictors of major adverse cardiac events in patients with unstable angina
Authors: Gyongyosi Mariann , Yang Paul , Hassan Ali , Domanovits Hans , Laggner Anton , Weidinger Franz , Glogar Dietmar 
Published: February 2009

AbstractBackground: Intravascular ultrasound (IVUS) predictors of native culprit lesion morphology for occurrence of major adverse cardiac events (MACE) have not been reported. Moreover, the published data on IVUS predictors of restenosis include patients with stable and unstable angina, although the development and progression of atherosclerosis related to unstable coronary syndrome is different from that of stable angina.Hypothesis: This study investigated whether IVUS‐de‐rived qualitative and quantitative parameters of native (prean‐gioplastic) plaque morphologic features can predict major adverse cardiac events in patients with unstable angina.Methods: Clinical (age, gender, coronary risk factors), qualitative and quantitative angiographic (lesion localization, morphology, pre‐ and postangioplastic minimal lumen diameter, reference diameter, and percent diameter stenosis), and IVUS variables (soft/fibrocalcific plaque, calcification, presence of thrombus or plaque disruption, different types of arterial remodeling, pre‐ or postangioplastic minimal lumen, external elastic membrane and plaque cross‐sectional area, and plaque burden of the target lesion and reference segments) were analyzed by regression analyses using the Cox model, assuming proportional hazards.Results: Of 60 consecutively enrolled patients, 21 suffered from MACE, while 39 remained event‐free during the follow‐up period. Multivariate regression analyses revealed that the presence of adaptive remodeling [p = 0.0177, risk ratio (RR) = 3.108, with 95% confidence interval (CI) = 1.371—8.289] and the preangioplastic lumen cross‐sectional area (p = 0.0130, RR = 0.869, with 95% CI = 0.667—0.913) are independent predictors of MACE during follow‐up, as is postangioplastic angiographic minimal lumen diameter (p = 0.0330, RR = 0.715 with 95% CI = 0.678—0.812).Conclusions: Adaptive remodeling and preangioplastic lumen cross‐sectional area determined by IVUS and postangioplastic minimal lumen diameter calculated by quantitative angiography are significant independent predictors of time‐dependent MACE in patients with unstable angina.
Circadian heart rate response to chronotherapy versus conventional therapy in patients with hypertension and myocardial ischemia
Authors: Glasser Stephen P. , Frishman William , White William B. , Stone Peter , Johnson Mary F. 
Published: February 2009

AbstractBackground: Changes in heart rate (HR) may contribute to the higher incidence of cardiovascular events in the morning.Hypothesis: The objectives of this analysis were to assess HR patterns in two populations (patients with chronic stable angina or stage I to HI hypertension) and to compare the effects of various antianginal and antihypertensive treatments on HR.Methods: This was a retrospective analysis of HR data from two clinical trials evaluating the efficacy of controlled‐onset, extended‐release (COER)‐verapamil. The effects of COER‐verapamil were compared with placebo, nifedipine gastrointestinal therapeutic system (GITS), amlodipine, and the combination of amlodipine and atenolol.Results: In patients with angina (n = 498), the change from baseline in HR following 4 weeks of treatment was —6.7 ± 10.5 beats/min in the COER‐verapamil group, —10.8 ± 10.8 beats/min in the amlodipine/atenolol group, + 2.5 ± 9.1 beats/min in the amlodipine monotherapy group, and —1.3 ± 10.5 beats/min in the placebo group (p < 0.001). Data were stratified based on whether patients experienced asymptomatic ischemia during baseline ambulatory electrocardiographic monitoring. The circadian HR pattern was morphologically similar in all groups; however, differences in the magnitude of HR response were evident. In the subset of patients with asymptomatic ischemia (n = 101), treatment with amlodipine monotherapy increased HR compared with placebo. In this same subset of patients, HR reductions were achieved with COER‐verapamil and amlodipine/atenolol. In patients with hypertension (n = 557), the change in HR following 10 weeks of treatment was —3.3 beats/min for patients treated with COER‐verapamil compared with + 2.0 beats/min for patients treated with nifedipine GITS (p < 0.0001, between‐group differences).Conclusion: This analysis demonstrates that morphologically similar circadian patterns of HR occur in both hypertensive patients and those with angina. In addition, significant variation exists among antianginal and antihypertensive agents regarding HR effects.
Effects of glibenclamide, a k atp channel blocker, on warm‐up phenomenon in type 11 diabetic patients with chronic stable angina pectoris
Authors: Öuvoünç KENAN 
Published: February 2009

AbstractBackground: Warm‐up phenomenon, one of the clinical models of ischemic preconditioning, refers to an increased tolerance to myocardial ischemia during the second of two consecutive exercise tests.Hypothesis: Blockers of K ATP channels, such as the sulfonylurea drugs, can induce loss of ischemic preconditioning. This study aimed to investigate the effects of glibenclamide, a sulfonylurea with a high affinity for myocardial K ATP channels, on the results of two consecutive exercise tests in diabetic patients with coronary artery disease.Methods: Eighteen type II diabetic patients with chronic stable angina pectoris participated in this study. All patients underwent two consecutive treadmill exercise tests with a recovery period of 15 min in fasting state. On the day after these exercise tests, 10 mg oral glibenclamide was given to the same patients and 30 min later 200 ml of 30% glucose solution was given orally. Half an hour later, which is the time of peak plasma levels of glibenclamide, two exercise tests were repeated consecutively with a 15 min recovery period.Results: There was no difference in blood glucose levels before and after exercise tests on each day (p > 0.05). Without glibenclamide, heart rate, rate‐pressure product at 1.5 mm ST depression, and peak exercise increased significantly (p < 0.05). Time to 1.5 mm ST‐segment depression and onset of pain, as well as duration of exercise also increased, but ST‐segment depression and ST‐recovery time significantly decreased (p < 0.05). In contrast, these values did not significantly change after glibenclamide (p > 0.05), with a significant drug—test interaction (p < 0.05, at two‐way ANOVA).Conclusions: Glibenclamide, an oral hypoglycemic agent with a KATP channel‐blocker activity, with a 10 mg oral dose, abolished the warm‐up phenomenon which is a clinical finding of ischemic preconditioning on two consecutive exercise tests. Therefore, glibenclamide should be used carefully in patients with coronary heart disease and diabetes mellitus since this agent leads to a decrease in ischemic threshold and exercise capacity.
Right ventricular infarction—diagnosis and treatment
Authors: Haji Showkat A. , Movahed Assad 
Published: February 2009

AbstractRight ventricular infarction (RVI) as assessed by various diagnostic methods accompanies inferior‐posterior wall myocardial infarction (MI) in 30 to 50% of patients. Recognition of the syndrome of RVI is important as it defines a significant clinical entity, which is associated with considerable immediate morbidity and mortality and has a well—delineated set of priorities for its management. Patients may clinically present with hypotension, elevated jugular venous pulse (JVP), and occasionally shock, all in the presence of clear lung fields. The ST—segment elevation of ⩾ 0.1 mV in the right precordial leads V 4 R is a readily available electrocardiographic sign used for diagnosis of RVI. Other diagnostic approaches for assessing RVI include echocardiography, radionuclide ventriculography, technetium pyrophosphate scanning, and hemodynamic measurements. The proper management of RVI includes volume loading to maintain adequate right ventricular preload, ionotropic support, and maintenance of atrioventricular synchrony. Reperfusion therapy should be initiated at the earliest signs of right ventricular dysfunction. Finally, complete recovery over a period of weeks to months is a rule in a majority of patients, suggesting right ventricular “stunning” rather than irreversible necrosis has occurred.
Low—molecular—weight heparins in acute myocardial infarction: RationaLe and results of a pilot study
Authors: Ross Allan M. , Coyne Karin , Hammond Melissa , Lundergan Conor F. 
Published: February 2009

AbstractBackground: Antithrombotic adjuncts to fibrinolytic drugs for acute myocardial infarction increase the rate and speed of infarct artery recanalization.Hypothesis: A low—molecular—weight heparin might be preferable to unfractionated heparin for this indication, as it has been shown to be in several other thrombus‐related vascular disorders.Methods: We performed a pilot study in 20 patients, all receiving aspirin and recombinant tissue plasminogen activator. Randomization was to standard dose intravenous unfractionated heparin or enoxaparin (the first dose given intravenously and followed by a subcutaneous administration). The endpoint was stability of anticoagulant effect.Results: Enoxaparin produced stable therapeutic anti—Xa levels with minimal effect on activated partial thromboplastin times. Unfractionated heparin produced wide swings of these parameters, often outside desired levels.Conclusions: Enoxaparin may be a better antithrombotic agent than conventional unfractionated heparin when used in conjunction with fibrinolytics.
Recent advances in dobutamine stress echocardiography
Authors: Usher Bruce W. , O'Brien Terrence X. 
Published: February 2009

AbstractDobutamine stress echocardiography (DSE) is a reliable cardiac risk stratifier that has widespread applicability because of its clinical accuracy and cost effectiveness. Dobutamine has positive inotropic and chronotropic effects and is commonly used in patients who cannot exercise or achieve an adequate heart rate response with exercise. Recently available long‐term results from several independent clinical trials, combined with enhancements in image quality, have improved the ability to detect significant coronary artery disease and determine myocardial viability. Dobutamine stress echocardiography has an excellent safety profile with clinical results superior to regular exercise electrocardiography and comparable with exercise echocardiography and radionucleotide perfusion stress imaging. Low‐dose dobutamine response can accurately predict dysfunctional yet viable myocardial regions that may improve with revascularization. Clinical studies are now available refining the common use of DSE preoperatively in female patients with valvular disease, as well as in the emergency department. Dobutamine stress echocardiography does have some limitations in discriminating particular regions of ischemia when multiple ventricular segments are involved and when the imaging is suboptimal. It can be applied using minimal additional resources in an otherwise functioning echocardiography laboratory and, with appropriate training, can result in clinical results comparable with those of large‐scale multi‐center trials. Ongoing improvements in technology and the development of new reagents such as myocardial contrast agents hold promise for further advancement in the near future.
High variability of retrograde fast pathway sensitivity to adenosine
Authors: Mewis Christian , Kühlkamp Volker , Mermi Johann , Bosch Ralph F. , Seipel Ludger 
Published: February 2009

AbstractBackground: Adenosine is widely used as a tool to assess the effectiveness of radiofrequency ablation of concealed accessory pathways.Hypothesis: The goal of this study was to determine the reliability of this test by studying the retrograde fast pathway sensibility in a large patient population with typical atrioventricular (AV) nodal reentry tachycardias. We sought also to determine whether AV nodal properties were predictive of a retrograde fast pathway sensitivity to adenosine.Methods: In all, 124 patients with inducible AV nodal reentrant tachycardia were included in this study. All patients received a clinically used standard dose of 12 mg adenosine during ventricular pacing, with 500 ms and a constant ventriculoatrial (VA) conduction via the fast pathway. Electrophysiologic parameters of the AV node were determined in all patients in order to correlate them with the adenosine sensitivity of the retrograde pathway.Results: In 74 patients, the injection of 12 mg adenosine resulted in a transient VA block, whereas no VA block occurred in the remaining 50 patients. In two patients, concealed accessory pathways were unmasked after the injection of adenosine. The adenosine sensitivity of the retrograde fast pathway was associated with longer retrograde conduction times and cycle lengths during AV nodal reentrant tachycardias.Conclusion: This study shows a high variability of retrograde fast pathway sensitivity to adenosine. Thus, in 40% of patients the lack of VA block after adenosine injection is not specific for persistent accessory pathway function after radiofrequency ablation. Electrophysiologic properties of patients with AV nodal reentrant tachycardias were different in patients with and without adenosine‐sensitive retrograde fast pathways, possibly indicating differential patterns of penetration of the retrograde fast pathway into the compact AV node.
Pulmonary embolus after coronary artery bypass surgery: A review of the literature
Authors: Shammas Nicolas W. 
Published: February 2009

AbstractPulmonary embolus (PE) after cardiac bypass surgery is an uncommon complication but carries with it high morbidity and mortality. The incidence of deep vein thrombosis (DVT) and PE after cardiac bypass varies depending on postoperative thromboprophylaxis, the presence of indwelling central venous catheters in the lower extremities, and early ambulation. The clinical diagnosis of DVT remains difficult and challenging. Pulmonary embolus is often the first occurring clinical event. The safety and effectiveness of preventative pharmacologic agents, such as subcutaneous unfraction‐ated or fractionated heparin or oral Coumadin, remain largely unknown. Heparin‐induced thrombocytopenia, generally associated with a high incidence of DVT and PE, occurs in approximately 3.8% of patients who have undergone cardiac surgery and are placed postoperatively on high‐dose intravenous unfractionated heparin. Sequential compression devices (SCD) have not been effective in reducing the incidence of DVT in an ambulating cardiac bypass patient when added to routine elastic graded compression stockings (GCS). Very large clinical trials are necessary to prove the effectiveness of pharmacologic or mechanical preventative measures in reducing the incidence of PE after cardiac surgery above the commonly used GCS, early ambulation, and aspirin. In a nonam‐bulating, higher‐risk cardiac bypass patient with slow recovery, a more aggressive prophylaxis regimen might be necessary for optimal prevention, although further data are needed to support this hypothesis.
Susceptibility of apolipoprotein B‐containing lipoproteins to oxidation and antioxidant status in acute coronary syndromes
Authors: Yesilbursa Dilek , Serdar Akin , Güllülü Sümeyye , Cordan Jale , Serdar Zehra , Dirican Melahat 
Published: February 2009

AbstractBackground: Oxidized lipoproteins may play an important role in the pathogenesis of atherosclerosis, and it has been shown that antioxidants have a protective effect against the progression of atherosclerosis.Hypothesis: The aim of this study was to investigate the oxidative susceptibility of apolipoprotein B‐containing lipoproteins and antioxidant status in patients with acute coronary syndromes and chronic stable angina pectoris.Methods: The study population included 70 patients with acute coronary syndromes (14 with recent acute myocardial infarction and 56 with unstable angina pectoris), 105 patients with stable angina pectoris, and 75 control subjects. In addition to conventional lipid and lipoprotein analysis, the susceptibility of apolipoprotein B‐containing lipoproteins to in vitro oxidation (lag phase) and plasma vitamin E and total carotene levels was measured.Results: The lag phase was significantly shorter in patients with acute coronary syndromes (45 ± 12 min) than in patients with stable angina pectoris (51 ± 10 min) and in control subjects (58 ± 9 min) (p < 0.0001). Both plasma vitamin E and total carotene levels were lowest in patients with acute coronary syndromes (1.11 ± 0.32 mg/dl and 119 ± 32 μg/dl, respectively), followed by patients with stable angina pectoris (1.25 ± 0.37 mg/dl and 132 ± 37 μg/dl) and then controls (1.52 ± 0.31 mg/dl and 167 ± 41 μg/dl).Conclusions: These data suggest that there is an intense oxidative process and a lower antioxidant status in acute coronary syndromes. This may lead to plaque instability due to the activation of the inflammatory response in coronary atherosclerotic lesions.
The assessment of myocardial viability and hibernation using resting thallium imaging
Authors: Perrone‐Filardi Pasquale , Chiariello Massimo , Underwood Richard 
Published: February 2009

AbstractRest‐redistribution thallium‐201 imaging is widely used to assess recovery of regional systolic dysfunction in patients with chronic coronary artery disease. In several studies, this technique has demonstrated very high sensitivity but reduced specificity, as reported in general for radionuclide imaging. In clinical terms, this implicates that many dysfunctional territories will not recover after revascularization despite a substantial amount of tracer uptake. Yet, the amount of tracer uptake in a given myocardial segment, although not perfect, remains the best indicator for predicting reversible dysfunction. In fact, the occurrence of redistribution after rest injection is not very common and it does not substantially contribute to the accuracy of the test. However, it is still undetermined whether the presence of redistribution is relevant for prognostic implications.
Aortic atherosclerotic lesions in the thoracic aorta detected by multiplane transesophageal echocardiography as a predictor of coronary artery disease in elderly patients
Authors: Parthenakis Fragiskos I. , Kochiadakis George E. , Skalidis Emmanuel I. , Kanakaraki Marina K. , Mezilis Nikos E. , Kanoupakis Emmanuel M. , Vardas Panos E. , Nihoyannopoulos Petros 
Published: February 2009

AbstractBackground: The presence of atherosclerotic lesions in the thoracic aorta by transesophageal echocardiography (TEE) appears to be a marker for the presence of significant coronary artery disease (CAD) in the general population.Hypothesis: We investigated whether atherosclerotic lesions in the thoracic aorta, by multiplane TEE, could be a marker for CAD in elderly patients.Methods: In all, 127 patients (67 men, 60 women, aged 68 ± 13 years), underwent a TEE study with imaging of the thoracic aorta and cardiac catheterization with coronary angiography. The presence of a distinct, linear, or focal, highly echogenic mass protruding into the vessel lumen was the criterion for the diagnosis of atherosclerotic plaque.Results: Atherosclerotic lesions were found in 30 of 36 patients (83.3%) with and in 20 of 91 (22%) without CAD. Of the 41 patients ≥ 70 years, atherosclerotic lesions were detected in 14 of 17 (82.3%) with and in 13 of 24 patients (54%) without CAD. The sensitivity, specificity, and positive and negative predictive values in this group were 82.3, 46, 52, and 78.6%, respectively. Multivariate logistic regression analysis revealed that in patients aged ≥ 70 years only advanced atherosclerotic lesions were independent predictors of significant CAD. However, the high negative predictive value of the method indicates that the absence of aortic plaque is a strong predictor of the absence of CAD.Conclusions: The presence of atherosclerotic lesions in the thoracic aorta is a strong predictor of CAD only in patients < 70 years old. However, the negative predictive value of the method is high for all patients regardless of age.