bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intrapulmonary artery infusion of urokinase for treatment of massive pulmonary embolism: A review of 26 patients with and without contraindications to systemic thrombolytic therapy
Authors: Mccotier C.J. , Chiang K.S. , Fearrington E.L. 
Published: February 2009

AbstractBackground: Pulmonary emboli (PE) are a common event seen in over 600,000 patients a year. Occurring suddenly, PE often result in a high rate of mortality. To combat the high rate of mortality, more aggressive therapies including the use of thrombolytics are often indicated. The use of intrapulmonary artery infusion of urokinase has been shown to promote rapid resolution of emboli and restoration of normal pulmonary hemodynamics.Hypothesis: The study was undertaken to review the effectiveness and safety of pulmonary artery infusion of urokinase in 26 patients with and without contraindications to the use of systemic thrombolytic therapy.Methods: We reviewed the outcomes of 26 patients who received infusion of urokinase, using a usual loading dose of 4,000 U/kg body weight given as a bolus, followed by 4,000 U/kg/h for 12 to 24 h, using either/or unilateral or bilateral infusions. Pulmonary angiograms were obtained prior to and following the urokinase infusions.Results: Intrapulmonary artery infusion of urokinase was given to 26 patients, 9 of whom had contraindications to the use of systemic thrombolytic therapy. Six patients were recent post operative, one was receiving oral anticoagulants, one was receiving chemotherapy with bleeding complications, and one had received cardiopulmonary resuscitation. Twenty of the patients returned to their baseline state (normal heart rate, blood pressure, and p02), one was minimally improved, and five deaths occurred. Of the five deaths, three occurred within 1 h of starting urokinase infusion, the remaining two died more than 36 h after treatment with urokinase as a result of their basic underlying disease. Minor bleeding occurred from puncture sites, two hematomas occurred at the puncture site, and there were two gastrointestinal bleeds, one of which occurred a week post urokinase therapy while the patient was receiving heparin and coumadin. No central nervous system bleeds occurred and no transfusions were required as a result of urokinase intrapulmonary artery infusions. The overall mortality rate in this series was 11.5%.Conclusions: Intrapulmonary artery infusion of urokinase in extensive pulmonary embolism is a safe and efficient treatment in patients with and without contraindication to the use of systemic thrombolytic therapy. With a usual loading dose of 4,000 U/kg body weight, followed by an infusion of 4,000 U/kg/h for 12 to 24 h, it produces significant and rapid resolution of pulmonary emboli with a low morbidity and mortality rate. In our series, the mortality rate was 11.5%, and none of the deaths was the direct result of urokinase therapy.
Irregularity of the ventricular rhythm during atrial fibrillation: Effect of slow atrioventricular nodal pathway ablation
Authors: John Camm A. , Frey Bernhard , Kreiner Gerhard , Gössinger Heinz David , Liebisch Bernhard , Sauermann Stefan 
Published: February 2009

AbstractBackground: The contribution of dual atrioventricular (AV) nodal pathway physiology to the irregularity of the ventricular rhythm during atrial fibrillation has not been clarified.Hypothesis: This study was performed to assess the effects of slow AV nodal pathway ablation on the irregularity of the ventricular rhythm during atrial fibrillation.Methods: Irregularity of the ventricular rhythm was quantified using analysis of heart rate variability. In 20 patients with AV nodal reentrant tachycardia, absolute heart rate variability during atrial fibrillation was quantified before and after slow AV nodal pathway ablation by the standard deviation of all NN intervals (SDNN). Relative heart rate variability was determined by computing the coefficient of variation, SDNN normalized for the standard deviation of the mean ventricular cycle length (MVCL‐AF).Results: The slope of the regression between MVCL‐AF and SDNN was significantly more gradual after slow pathway ablation (slope 0.39 vs. 0.23, p <0.001). Coefficient of variation increased in 12 patients with heart rates > 120 beats/min at baseline (18.6 ± 3.9 vs. 22.1 ± 2.7% MVCL‐AF, p <0.05), but decreased in 8 patients with heart rates < 120 beats/min at baseline (25.6 ± 3.1 vs. 22.2 ± 2.2% MVCL‐AF, p = 0.05). Furthermore, coefficient of variation correlated with MVCL‐AF only at baseline (slope 0.034, r=0.66), but no relation was found after slow pathway ablation (slope 0, r=0).Conclusions: Slow AV nodal pathway ablation alters the relation between absolute heart rate variability and mean ventricular rate during atrial fibrillation and eliminates cycle length dependency of relative heart rate variability. These data indicate that dual AV nodal pathway physiology contributes to the irregularity of the ventricular rhythm during atrial fibrillation.
Percutaneous balloon valvuloplasty for congenital pulmonary valve stenosis in adults
Authors: Lip Gregory Y. H. , Singh Shyam P. , de Giovanni Joseph 
Published: February 2009

AbstractBackground: Although pulmonary valvular stenosis is not uncommon in adults, there are few reports of percutaneous pulmonary valvuloplasty in adults, despite the possibility of avoiding heart surgery.Aim: This report describes the experience in adult patients undergoing this procedure and evaluates its effectiveness and tolerance.Methods: Over an 8‐year period (1989–1997), pulmonary valvuloplasty was considered in 22 adult patients [8 men, 14 women; mean age 28.0 years ± standard deviation (SD) 10.3; range 16–46 years] with congenital pulmonary valve stenosis. Sixteen patients were asymptomatic with pulmonary systolic murmurs, although 6 patients presented with dyspnea. Before the procedure, the mean transpulmonary valve gradient was 53.2 ± 24.8 mmHg SD, with a mean right ventricular systolic pressure of 74.6 ± 28.4 mmHg SD, and mean pulmonary artery pressure was 21.4 ± 6.4/10.2 ± 3.9 mmHg.Results: The procedure was successful in 19 patients (6 men, 13 women) and was well tolerated and free of complications. Following the procedure, the mean transvalvular gradient was 15.5 ± 11.5 mmHg, with a mean right ventricular systolic pressure of 40.5 ± 13.6 mmHg and a mean pulmonary systolic pressure of 24.3 ± 7.4 mmHg. This represented a mean fall in transpulmonary valve gradient of 42.4 ± 22.0 mmHg (paired t‐test, p < 0.0001). After a mean follow‐up of 20.1 months (13.4 SD), most patients remained well and asymptomatic, although two patients required repeat valvuloplasty.Conclusion: Pulmonary valvuloplasty is a well tolerated and effective treatment for pulmonary valve stenosis in adults, with few complications and no need for surgery. This procedure should be considered as the primary treatment of adult patients with pulmonary valve stenosis.
Electrocardiographic predictors of right ventricular volume measured by magnetic resonance imaging late after total repair of tetralogy of fallot
Authors: Book Wendy M. , Hurst J. Willis , Parks W. James , Hopkins Katherine L. 
Published: February 2009

AbstractBackground: Right ventricular dysfunction occurs in many patients with significant pulmonary valve regurgitation late after initial total repair of tetralogy of Fallot. Methods to predict which of these patients are at increased risk of late morbidity and mortality are not yet known.Hypothesis: This study evaluated electrocardiographic (ECG) predictors of severe right ventricular dilatation determined by magnetic resonance imaging (MRI) volumes in patients with tetralogy of Fallot late after initial corrective repair.Method: We retrospectively reviewed the ECGs and MRI right ventricular volume measurements of 20 patients (age 4.4 to 19.3 years, mean 10.0 years) with significant pulmonary valve regurgitation late after repair of tetralogy of Fallot. All patients had enlarged, hypokinetic right ventricles by echocardiography. The patients were grouped based on an indexed right ventricular end‐diastolic volume (RVEDV/BSA) of <102 ml/m2 (Group 1) or ≥ 102 ml/m2 (Group 2). We determined the sensitivity, specificity, positive and negative predictive values of QRS duration, and mean frontal plane QRS axis for predicting right ventricular volumes.Results: A maximal QRS duration of ≥ 150 ms or a northwest quadrant frontal plane QRS axis had 85% sensitivity, 86% specificity, 92% positive predictive value, and 75% negative predictive value for predicting an RVEDV/BSA of ≥ 102 ml/m2. The mean QRS duration was significantly longer in Group 2 than in Group 1 patients (156 ms vs. 123 ms, p=0.005).Conclusions: In patients late after repair of tetralogy of Fallot with significant pulmonary valve regurgitation, a maximal manually measured QRS duration of ≥ 150 ms and/or a frontal plane QRS northwest quadrant axis can predict patients with marked right ventricular enlargement. The presence of either of these findings on the ECG signifies patients who require further evaluation and consideration for pulmonary valve replacement.
Coronary artery blood how: Physiologic and pathophysiologic regulation
Authors: Feliciano Lillybeth , Henning Robert J. 
Published: February 2009

AbstractAcute myocardial ischemia, which results from a significant imbalance between myocardial oxygen demands and myocardial oxygen supply, occurs in as many as six million persons with atherosclerotic coronary artery disease in the United States. Accordingly, a clear understanding of the physiologic and pathophysiologic factors that influence coronary artery blood flow is important to the clinician and provides the basis for the judicious use of medications for the treatment of patients with atherosclerotic coronary artery disease. This review discusses the endothelial, metabolic, myogenic, and neurohumoral mechanisms of coronary blood flow regulation and the interaction of the different mechanisms in the regulation of coronary blood flow. The importance of nitric oxide in coronary blood flow regulation is emphasized. We also discuss the common clinical problems of hyperlipidemia and coronary atherosclerosis, coronary artery spasm, and systemic arterial hypertension that result in coronary artery endothelial dysfunction, the impaired production and increased inactivation of nitric oxide, and impairment in coronary blood flow regulation. This information is important to clinicians because more than forty million people in the United States have atherosclerotic or hypertensive heart disease and therefore are at risk for significant myocardial complications due to impairment of coronary blood flow regulation.
Racial differences in patients with heart failure
Authors: Afzal Adnan , Ananthasubramaniam Karthik , Sharma Nagaraja , Ai‐Malki Qahtan , Ali Abbas S. , Jacobsen Gordon , Jafri Syed M. 
Published: February 2009

AbstractBackground and hypothesis: Limited data exist regarding racial differences in heart failure. The objective of this prospective study was to document racial differences in the baseline demographics and patterns of health care utilization and outcomes in patients with heart failure.Methods: The data on 163 consecutive patients (113 black, 50 white) admitted with a diagnosis of heart failure confirmed by pulmonary congestion on chest x‐ray were prospectively evaluated. Patient demographics, physical examination findings at admission, comorbid conditions, and medications at admission and discharge were analyzed. Follow‐up was performed to document visits to the physician's office after discharge and readmission rate during a 6‐month time period.Results: Compared with whites, blacks were younger in age (mean age 63.8 ± 13.7 years vs. 70.8 ± 13.1, p = 0.003), and had a higher prevalence of hypertension (86 vs. 66%, p = 0.004), left ventricular hypertrophy (24 vs. 8%, p=0.02), ejection fraction <40% (64 vs. 43%, p = 0.03), and readmission rate (33 vs. 18%, p = 0.05). Whites had a higher prevalence of atrial fibrillation (42 vs. 21 %, p = 0.006) and more frequently followed up with their cardiologists as outpatients (58 vs. 39%, p = 0.04).Conclusion: Significant racial differences exist in patients with heart failure with regard to age, incidence, etiologic factors, left ventricular hypertrophy, left ventricular function, and clinical follow‐up. It is important to consider these racial differences in the evaluation and management of patients with heart failure.
An evolving role of transesophageal echocardiography for the monitoring of interventional catheterization in children
Authors: Cheung Yiu‐Fai , Leung Maurice P. , Lee Joselyn , Yung Tak‐Cheung 
Published: February 2009

AbstractBackground and hypothesis: Transesophageal echocardiography (TEE) is increasingly utilized for the monitoring of interventional cardiac catheterization in children. The initial nondiscriminant use is giving way to a more selective approach. The current role and usefulness of this imaging modality are described.Methods: Between 1991 and 1995, 44 patients (mean age 7.4 ± 5 years, weight 22.8 ± 14.2 kg) underwent interventional cardiac catheterizations performed under TEE monitoring. The interventional procedures included (1) those involving creation, enlargement, or closure of an interatrial communication; (2) balloon dilatation of stenotic lesions; and (3) occlusion of arterial ducts. Transesophageal echocardiographic monitoring was judged to be either of great value, contributory, or of little use if the interventional procedure and choice of instrument relied heavily upon, was guided, or not affected by the information obtained from the ultrasonic investigation, respectively.Results: Transesophageal echocardiography was judged to be of great value in the monitoring of 18 (40%) procedures involving either the creation, enlargement, or closure of interatrial communications. This included 4 transseptal punctures, 4 blade septectomies for relieving restrictive atrial septal defects (n = 3) and an enlargement of the communication between the superior and inferior chambers of the divided left atrium in cortriatriatum, and 11 closures of a secundum atrial septal defect. Only the ultrasonic monitoring could clearly visualize the interatrial partition to provide real‐time guidance on the positioning of the instrument to carry out the invasive procedures. Transesophageal echocardiography provided clear images of the hinge points of the aortic and mitral valves, the dimension of the narrowed pulmonary venous pathway in patients after venous switch operation. This facilitated the choice of the correct size of the balloon for dilatation in 11 patients (24%) and provided immediate postdilatation hemodynamic assessment. As for balloon dilation of subvalvar ventricular outflow tract obstruction (n = 3), aortic coarctation (n = 6), and occlusion of persistent arterial duct (n=7), TEE offered no obvious advantage over fluoroscopy with angiography. The monitoring was judged to be of little value for the 16 (36%) procedures.Conclusion: Transesophageal echocardiographic monitoring is of great value in interventional procedures involving the atrial septum and enhances interventional procedures involving obstructive lesions of the left heart in children.
Contrast echocardiography in the diagnosis of myocardial stunning
Authors: Nagy Andras , Lengyel Mária , Morales Maria Aurora , Marzilli Mario , L'Abbate Antonio , Distante Alessandro 
Published: February 2009

AbstractThe identification of viable myocardium within dysfunctional myocardium has important clinical implications. By using a microvascular tracer, myocardial contrast echocardiography may have the potential for prediction of myocardial viability in the acute and subacute phases of myocardial infarction. In the case presented, the normal myocardial perfusion observed after intravenous injection of the contrast agent, combined with severe wall motion abnormality following prolonged chest pain, suggested myocardial stunning. This was confirmed by normal coronary angiography and by restoration of normal left ventricular function at 1‐month follow‐up echocardiography.
Lipid‐Altering Efficacy and Safety of Simvastatin 80 mg/Day: Long‐Term Experience in a Large Group of Patients with Hypercholesterolemia
Authors: Ose Leiv , Davidson Michael H. , Insull William , Wu Mei , Tate Ann C. , Melino Michael R. , Mercuri Michele , Mitchel Yale B. , Stein Evan A. , Kastelein Johannes J. P. , Scott Russell S. , Hunninghake Donald B. , Campodonico Santiago , Escobar Ivan D. , Stepanavage Michael E. , Schrott Helmut G. 
Published: February 2009

AbstractBackground: Elevated levels of low‐density lipoprotein (LDL) cholesterol promote the development of atherosclerosis and coronary heart disease.Hypothesis: Simvastatin 80 mg/day will be more effective than simvastatin 40 mg/day at reducing LDL cholesterol and will be well tolerated.Methods: Two similar, randomized, multicenter, controlled, double‐blind, parallel‐group, 48‐week studies were performed to evaluate the long‐term lipid‐altering efficacy and safety of simvastatin 80 mg/day in patients with hypercholesterolemia. One study conducted in the US enrolled patients meeting the National Cholesterol Education Program (NCEP) LDL cholesterol criteria for pharmacologic treatment. In the other multinational study, patients with LDL cholesterol levels ≥4.2 mmol/l were enrolled. At 20 centers in the US and 19 countries world‐wide, 1,105 hypercholesterolemic patients, while on a lipid‐lowering diet, were randomly assigned at a ratio of 2:3 to receive simvastatin 40 mg (n = 436) or 80 mg (n = 669) once daily for 24 weeks. Those patients completing an initial 24‐week base study were enrolled in a 24‐week blinded extension. Patients who had started on the 80 mg dose in the base study continued on the same dose in the extension, while those who had started on the 40 mg dose were rerandomized at a 1:1 ratio to simvastatin 40 or 80 mg in the extension.Results: There was a significant advantage in the LDL cholesterol‐lowering effect of the 80 mg dose compared with that of the 40 mg dose, which was maintained over the 48 weeks of treatment. The mean percentage reductions (95% confidence intervals) from baseline in LDL cholesterol for the 40 and 80 mg groups were 41% (42, 39) and 47% (48, 46), respectively, for the 24‐week base study, and 41% (43, 39) and 46% (47, 45), respectively, after 48 weeks of treatment (p < 0.001 between groups). Larger reductions in total cholesterol and triglycerides were also observed with the 80 mg dose compared with the 40 mg dose at Weeks 24 and 48. Both doses were well tolerated, with close to 95% of patients enrolled completing the entire 48 weeks of treatment. Myopathy (muscle symptoms plus creatine kinase increase > 10 fold upper limit of normal) and clinically significant hepatic transaminase increases (> 3 times the upper limit of normal) occurred infrequently with both doses. There was no significant difference between the groups in the number of patients with such increases, although there were more cases for both with the 80 mg dose.Conclusions: Compared with the 40 mg dose, simvastatin 80 mg produced greater reductions in LDL cholesterol, total cholesterol, and triglycerides. Both doses were well tolerated.
Antidromic atrioventricular reentrant tachycardia mimicking ventricular tachycardia in the setting of previous myocardial infarction
Authors: Dagres Nikolaos , Clague Jonathan R. , Kottkamp Hans , Breithardt Günter , Borggrefe Martin 
Published: February 2009

AbstractThe differentiation between ventricular tachycardia and broad‐complex supraventricular tachycardia can be extremely difficult, particularly in emergency situations. We report a case of hemodynamically compromising broad‐complex tachycardia in a 63‐year‐old man. The patient had previously sustained an anteroseptal myocardial infarction and had subsequently undergone coronary artery bypass surgery because of triple‐vessel coronary artery disease. Intravenous treatment with ajmalin terminated the tachycardia and revealed preexcited QRS complexes compatible with the presence of a left‐sided atrioventricular accessory pathway. An antidromic atrioventricular reentrant tachycardia (identical to the clinical tachycardia) was induced during an electrophysiologic study. In conclusion, there are several causes of broad‐complex tachycardia, even in patients with previous myocardial infarction, and, where doubt exists, electrophysiologic studies should be performed.
Cardiac autonomic tone and its relation to nonsustained ventricular tachyarrhythmias in idiopathic dilated cardiomyopathy
Authors: Hoffmann Jurgen , Grimm Wolfram , Menz Volker , Maisch Bernhard 
Published: February 2009

AbstractBackground: In contrast to postinfarct patients, little is known about cardiac autonomic tone and its relation to spontaneous ventricular tachyarrhythmias in idiopathic dilated cardiomyopathy (IDC). Both heart rate variability (HRV) and baroreflex sensitivity (BRS) are indices of autonomic innervation of the heart.Hypothesis: The aim of the present study was to determine the relation between cardiac autonomic tone assessed by HRV and BRS and spontaneous nonsustained ventricular tachycardia (NSVT) on Holter in a large patient population with IDC.Methods: 24‐h digital Holter recordings including HRV analysis and BRS testing were prospectively performed in 137 patients with IDC and preserved sinus rhythm. Mean age was 48±12 years, and mean left ventricular (LV) ejection fraction was 32±9%. The HRV analysis on Holter included the mean RR interval (RRm), the standard deviation of all normal RR intervals (SDNN), the square root of the mean of the squared differences between adjacent normal RR intervals (rMSSD), and the proportion of adjacent normal RR intervals differing more than 50 ms (pNN50). Testing for BRS was performed noninvasively using the phenylephrine method.Results: Of 137 study patients, 42 (31%) had spontaneous NSVT on 24‐h Holter. Compared with patients without NSVT, patients with NSVT on Holter had a higher New York Heart Association (NYHA) functional class (NYHA III: 40 vs. 18%, p<0.01), a lower ejection fraction (29±9 vs. 34±9%, p=0.01), and an increased LV end‐diastolic diameter (69±8 mm vs. 66±7 mm, p=0.03). The HRV variables rMSSD, pNN50, RRm, and BRS did not differ significantly between patients with and without spontaneous NSVT. Only SDNN on Holter was slightly lower in patients with versus without NSVT (106±45 vs. 121±46 ms, p=0.08).Conclusions: Patients with IDC and spontaneous NSVT on Holter are characterized by a higher NYHA functional class, a lower LV ejection fraction, an increased LV end‐diastolic diameter, and a tendency toward a lower SDNN value compared with patients without NSVT. The remaining measures of HRV including rMSSD and pNN50 reflecting primarily tonic vagal activity, as well as BRS reflecting predominantly reflex vagal activity, were similar in patients with and without NSVT. The prognostic significance of these findings in patients with IDC is currently under investigation in the Marburg Cardiomyopathy Study (MACAS) at our institution.