bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of thrombolytic therapy on the incidence of left ventricular thrombi after acute anterior myocardial infarction: Role of successful reperfusion
Authors: Ileri Mehmet , Tandoǧan Izzet , Koşar Feridun , Yetkin Ertan , Büyükaşik Yahya , Kütük Emine
Published: February 2009

Background: Previous studies have reported controversial results regarding the effectiveness of systemic thrombolysis in preventing left ventricular (LV) thrombus after acute myocardial infarction (MI).

Hypothesis: This study was performed to evaluate the influences of thrombolysis, and particularly successful reperfusion, on the incidence of LV thrombus formation after acute anterior MI.

Methods: in all, 191 patients suffering from a first attack of acute anterior MI were prospectively evaluated by two‐dimensional echocardiography and coronary angiography, performed at the end of the first week and within the first two weeks of MI, respectively. Of these, 98 who presented within 12 h of onset of symptoms received intravenous streptokinase (1.5 million IU), while the remaining 93 patients who, either because of contraindications or late admission, did not receive thrombolytic treatment served as control group. All patients received aspirin and full‐dose anticoagulation with intravenous heparin. Successful reperfusion in the streptokinase group was assessed by enzymatic and electrocardiographic evidence.

Results: The overall incidence of LV thrombi was 24.6% (47/191). When all patients were evaluated, no statistically significant difference was found between the frequency of LV thrombi in the patients who had thrombolysis (22.4%) and those who did not (26.8%), despite a trend toward the formation of fewer thrombi in the initial group (p > 0.05). However, the patients who had successful reperfusion with streptokinase (n = 64) had significantly reduced incidence of LV thrombi compared with those who did not receive thrombolytic therapy (20 vs. 26.8%, p < 0.05). Stepwise multivariate analysis suggested that LV abnormal wall motion score (p = 0.01) and presence of LV aneurysm were independent predictors of LV thrombus formation in patients with acute anterior MI.

Conclusion: Not all patients who received streptokinase for acute anterior MI, but only those with successful reperfusion had reduced incidence of LV thrombi. The favorable effects of thrombolysis on LV thrombus formation are probably due to the preservation of global LV systolic function.
Percutaneous mitral balloon valvuloplasty
Authors: Mayes Charles E. , Cigarroa Joaquin E. , Lange Richard A. , David Hillis L.
Published: February 2009

Almost all mitral stenosis (MS) is rheumatic in etiology. The patient with MS who is symptomatic despite medical therapy should undergo percutaneous mitral balloon valvuloplasty or mitral valvular surgery (commissurotomy or replacement). The choice of procedure is determined by patient preference and the echocardiographic morphologic features of the valvular and subvalvular apparati. With balloon valvuloplasty, the rate of success is > 90%. At institutions where operators are experienced with balloon valvuloplasty and open surgical commissurotomy, their acute and long‐term results are comparable. Balloon valvuloplasty occasionally is associated with complications, including death in 0 to 1%, moderate or severe valvular regurgitation in 3 to 5%, and systemic embolization in 1 to 3%.
Prospective evaluation of the coronary sinus anatomy in patients undergoing electrophysiologic study
Authors: Weiss Christian , Willems Stephan , Meinertz Thomas , Kuck Karl‐Heinz , Cappato Riccardo
Published: February 2009

Background: Previous retrospective studies could find a predominant incidence of coronary sinus (CS) anomalies in patients with accessory pathways and a characteristic anatomy of the CS ostium in patients with atrioventricular nodal reentrant tachycardias (AVNRT).

Hypothesis: In the present prospective study, CS angiograms were prospectively performed to analyze the incidence of CS anomalies and to measure the diameters of the CS ostium.

Methods: The study included patients referred for electrophysiologic study and catheter ablation of various tachyarrhythmias. The anatomy of the CS and its side branches was visualized [left anterior oblique (LAO) 30°, right anteri‐ or oblique (RAO) 30°] by retrograde angiography in 204 consecutive patients (82 women, 122 men, age 45 ± 15 years); of these, 120 presented with 123 accessory pathways (45 left‐sided, 33 right‐sided, 45 septal). The diagnosis in the remaining patients was atrioventricular nodal reentrant tachycardia in 43 cases, atrial tachycardia or atrial fibrillation in 12, and ventricular tachycardia in 15. In 14 patients, the indication for the eletrophysiologic study was an unexplained syncope. The CS angiogram was evaluated for anomalies and the size of the CS ostium was manually measured in both projections.

Results: Anomalies of the CS defined as diverticula, persistent left superior vena cava, or enlarged CS ostia were found in 18 patients (9%). Of those, CS diverticula were found in nine patients, all with a posteroseptal or left posterior manifest accessory pathway, which was abolished within the neck of the diverticulum in seven patients and at the posteroseptal tricuspid annulus in two patients. Persistence of the left superior vena cava was found in five patients, four had atrioventricular reentrant tachycardia secondary to five accessory pathways (left free wall in four, right midseptal in one), and one patient had atrioventricular nodal reentrant tachycardia (AVNRT). Enlargement of the CS ostium of > 25 mm width was detected in nine patients (5%), of whom four had AVNRT. However, the width of the CS ostium generally did not differ significantly between patients with AVNRT (LAO: 14.4 ± 5.6; RAO 9.3 ± 2.4 mm) compared with the control group (LAO 13.4 ± 4.1; 8.2 ± 1.9 mm).

Conclusions: Anomalies of the CS as diverticula, persistent superior vena cava, or enlargement of the CS ostium are predominantly found in patients with accessory pathway‐related tachycardias. Diverticula of the proximal CS were found in 7% of patients with accessory pathways; in these cases, ablation succeeded mostly by radiofrequency (RF) current delivery in the neck of the diverticulum. Enlargement of the CS ostium was more often seen in patients with AVNRT than in all other patients. However, in general the measurements of the coronary sinus ostium did not significantly differ in patients with AVNRT compared with the control group.
Electron beam computed tomography: Screening for coronary artery disease
Authors: Budoff Matthew J. , Brundage Bruce H.
Published: February 2009

The need to detect coronary atherosclerosis early in its course has been well recognized by clinicians and epidemiologists for decades. The ability to identify populations with a greater prevalence of coronary disease prior to manifestation of illness would greatly reduce cardiac morbidity and mortality. Electron beam computed tomography (EBCT) uniquely combines the characteristics of speed and excellent density resolution that have led to a rebirth of interest in detecting coronary calcium as a means of screening asymptomatic populations for coronary atherosclerosis. Electron beam computed tomography is noninvasive and widely applicable. It can both detect and quantitate the presence of coronary atherosclerosis. A positive test has diagnostic and prognostic significance, predicting future cardiac events and the extent of atherosclerosis, including the probability of obstructive coronary artery disease (CAD). Multiple studies demonstrate a 6‐ to 35‐fold increased risk of developing a cardiac event with elevated calcium scores. A negative test is highly predictive for excluding obstructive CAD. The cost ranges from $300 to $400, similar to that of an exercise treadmill test. Moreover, scanning for coronary calcium does not require injection of contrast medium, requiring no patient preparation or exercise; therefore, a CT technician can perform the study without supervision. The entire procedure takes < 10 min to perform. These features make EBCT a potential screening test for occult CAD in symptomatic and asymptomatic persons.
Predictors of early and late ventricular remodeling after acute myocardial infarction
Authors: Sanchis Juan , Insa Luis D. , Berenguer Alberto , Chorro Francisco J. , Llácer Angel , López‐Lereu María Pilar , López‐Merino Vicente , Bodí Vicente
Published: February 2009

Background: The determinants of the early and late stages of the ventricular remodeling process after infarction are not well defined.

Hypothesis: The study was undertaken to evaluate the factors that condition the time course of left ventricular dilation during the first 6 months after infarction.

Methods: The study group consisted of 74 patients with a first intermediate‐large (≥ 4 Q waves) acute myocardial infarction. Contrast left ventricular and coronary angiograms were performed at 7 ± 1 and 175 ± 25 days after infarction. Left ventricular volumes, regional function and infarction artery status were quantified. Percutaneous transluminal coronary angioplasty (PTCA) was performed in the early angiogram in 31 patients.

Results: in the early angiogram, 13 patients showed ventricular remodeling (end‐diastolic volume > 90 ml/m2). A larger extent of dysfunction was the only predictor (p < 0.002) of early remodeling. At 6 months, a smaller, early end‐diastolic volume (p < 0.0001) and a poorer regional function recovery (p < 0.05) were independently related to late diastolic enlargement, and a poorer regional function recovery (p < 0.0001) and a smaller, early end‐systolic volume (p < 0.009) were independently related to late systolic enlargement. One patient with compared with 20 patients without early remodeling (p < 0.04) presented with late remodeling (increment of the end‐diastolic volume > 20% at 6 months). in patients with early remodeling, the end‐diastolic volume did not change significantly (101 ± 13 vs. 94 ± 22 ml/m2, NS) at 6 months; despite this, they maintained larger diastolic volumes than patients with late remodeling (81 ± 12 ml/m2, p < 0.04) at 6 months. Infarction artery status did not influence the evolution of ventricular volumes and regional function.

Conclusions: (1) A large infarct size is the main determinant of postinfarction remodeling. (2) Such infarct size‐dependent ventricular dilation occurs early and does not tend to increase in late stage; in contrast, some cases of intermediate‐large size infarcts without early remodeling exhibit late remodeling associated with a poor late recovery of regional function. (3) Recovery of regional function (indicating myocardial viability) rather than infarction artery status plays a role in the late ventricular remodeling process.
Effect of angiotensin‐converting enzyme gene polymorphism on left ventricular remodeling after anteroseptal infarction
Authors: Nagashima Junzo , Kunishima Tomoyuki , Nobuoka Sachihiko , Murayama Masahiro , Musha Haruki , So Takehiko
Published: February 2009

Background and hypothesis: Genetic influence on cardiac remodeling is uncertain. The purpose of this study is to determine the effects of polymorphism of the angiotensin‐converting enzyme (ACE) gene on cardiac remodeling after myocardial infarction.

Methods: The subjects were 43 patients with old anteroseptal myocardial infarction. Based on the polymorphism of the ACE gene, they were classified into a deletion group of 25 patients (D/D genotype in 4 and D/I genotype in 21) and an insertion group of 18 patients (all I/I genotype). Echocardiograms were used to determine left ventricular end‐diastolic and end‐systolic diameters, interventricular septal and posterior wall thicknesses, left ventricular mass, left atrial diameter, and left ventricular ejection fraction. Blood concentrations of atrial and brain natriuretic peptide were also measured.

Results: Left ventricular end‐systolic and end‐diastolic dimensions, left ventricular mass, and levels of both atrial and brain natriuretic peptide were significantly higher in the deletion group. in contrast, septal thickness, posterior wall thickness, and ejection fraction showed no differences between the two groups.

Conclusions: in patients with old anteroseptal infarction, ACE gene polymorphism of the D/D and D/I genotypes has a stronger influence on left ventricular remodeling than polymorphism of the I/I genotype.
Determinants of collateral development in patients with acute myocardial infarction
Authors: Fujita Masatoshi , Otsuka Ken‐Ichi , Nakae Izuru , Ueda Kinzo , Tamaki Shun‐Ichi , Kihara Yasuki , Hasegawa Koji , Nohara Ryuji , Sasayama Shigetake
Published: February 2009

Background: The presence or absence of collateral circulation to the infarct‐related coronary artery in acute myocardial infarction (AMI) significantly impacts on infarct size and resulting left ventricular function. However, the determinants of collateral development have not been clarified.

Hypothesis: The purpose of this study was to elucidate the determinants of collateral development in humans.

Methods: The study group consisted of 248 patients (178 men, 70 women; mean age 63 years) undergoing coronary angiography within 12 h after the onset of a first AMI. All patients exhibited complete occlusion of the infarct‐related artery. The extent of collateral circulation to the area perfused by the infarct‐related artery was graded as none, or poorly or well developed, depending on the degree of opacification of the occluded coronary artery on the contralateral injection of contrast.

Results: Well‐developed collateral circulation was observed in 92 of the 248 patients (37.1%). The prevalence of well‐developed collaterals was 57% in patients with a history of angina pectoris prior to AMI, which was significantly (p < 0.0001) higher than the 26% in those without a history of angina. Multivariate stepwise logistic regression analysis was then applied to identify predictors of collateral development. Possible determinants of collateral development were long‐standing preinfarction angina, severity of coronary artery disease, age, gender, and coronary risk factors (hypertension, diabetes, hypercholesterolemia, smoking). This analysis revealed that only the presence of a history of angina pectoris prior to AMI was a significant predictor of collateral development (p < 0.0001).

Conclusions: A history of angina pectoris prior to AMI is a clinical marker for coronary stenoses. Since severe coronary stenoses can provide stimuli that lead to collateral development, it is reasonable that a history of angina would also be a clinical marker for collateral vessels.
Global t‐wave inversion: Limited QT dispersion despite qtc prolongation—a correlate of benignity in patients with strikingly abnormal electrocardiograms
Authors: Desai Sweta A. , Mehrok Sandeep , Spodick David H.
Published: February 2009

Background: The global T‐inversion (GTI) electrocardiogram (ECG) is strikingly abnormal with major QTc prolongation, but with a surprisingly good prognosis by Kaplan‐Meier curve. This contrasts with most significant QTc prolongations.

Hypothesis: This study was undertaken to ascertain QT interval dispersion (QTd) in global T wave inversion, a clinically benign long QTc ECG.

Methods: Longest and shortest QT intervals in all 12 leads in 35 consecutive patients with GTI were determined by two mutually blinded observers. QTd was determined by subtraction (maximum – minimum) and QTc was calculated using the Bazett formula.

Results: There was a 2:1 female preponderance. QTc was prolonged and equal for men (0.471) and women (0.469). Observer variability of under 2% permitted averaging of QT measurements. Composite mean QTd was 55 ms. The literature revealed a range of QTd in normal subjects of 39 to 59 ms (mostly 49 to 59 ms). Patient series with abnormal QTd were well above this level.

Conclusion: Despite a strikingly abnormal ECG with marked QTc prolongation, QT dispersion was limited in global T inversion, consistent with its previously demonstrated benignity.
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

Background: 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

Background: 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

Background: 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

Background: 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

Acute 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

Background 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

Background 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

The 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

Background: 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

The 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

Background: 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.
Intensity of antianginal therapy in patients referred for coronary angiography: A comparison of fee‐for‐service and health maintenance organization therapeutic strategies
Authors: Samuels Bruce A. , Diamond George A. , Denton Timothy A. , Mahrer Peter R.
Published: February 2009

Background: No formal criteria have been developed to guide medical therapy for angina prior to revascularization, and no comparisons have been made between health maintenance organization (HMO) and fee‐for‐service (FFS) hospitals with respect to angina treatment.

Hypothesis: Using a literature‐based measure of medical intensity, we tested the hypothesis that there is no difference in anginal medical therapeutic intensity between HMO and FFS systems.

Methods: For each antianginal drug, we developed a model from which an intensity score between 0 and 100 could be calculated. Average and maximal daily doses of drug were fit to a sigmoid curve such that they represented scores of 50 and 99, respectively. Overall intensity scores were obtained by weighted and unweighted averaging of three scores from nitrates, calcium‐channel blockers, and beta blockers. This model was applied to 199 patients undergoing angiography at an FFS and an HMO hospital.

Results: HMO patients were taking more classes of antianginal drug (1.9 vs. 1.0, p < 0.001). Overall unweighted (17.7 vs. 11.7, p = 0.02) and weighted (27.3 vs. 16.9, p = 0.003) intensity scores for both HMO and FFS patients were low. HMO intensity scores for the use of beta blockers were greater than FFS scores (19.2 vs. 9.6, p = 0.002). The intensity scores for the use of nitrates and calcium blockers were similar.

Conclusions: Models for the measurement of anginal medical therapy intensity can provide important information regarding medical therapy prior to revascularization. The overall intensity of medical therapy was low in both health care systems. These findings have important implications for patient management, guideline development, and national healthcare policy.
Severity of residual stenosis of infarct‐related lesion and left ventricular function after single‐vessel anterior wall myocardial infarction: Implication of st‐segment elevation in lead avl of the admission electrocardiograms
Authors: Yoshino Hideaki , Kachi Eisei , Shimizu Hisashi , Taniuchi Masato , Yano Kohei , Udagawa Hiroshi , Kajiwara Tatsuto , Shimoyama Katsuya , Ishikawa Kyozo
Published: February 2009

Background: The relationship between the severity of chronic‐phase stenosis of infarct‐related lesions (IRLs) and chronic left ventricular function in anterior acute myocardial infarctions (AMI) has not been adequately investigated.

Hypothesis: This study investigated whether ST elevation in lead aVL of admission electrocardiogram (ECG) would be a determinant factor of the relationship between the severity of stenosis of the IRL and chronic left ventricular function after anterior wall AMI.

Methods: One month after AMI, the IRL was evaluated by coronary angiography in 98 patients with anterior AMI, and left ventricular ejection fraction (LVEF) was determined using multigated radionuclide angiocardiography. Patients were classified according to the severity of the IRL: patients with 100% occlusion (Group O), patients with 90 to 99% stenosis (Group H), and patients with ≤ 75% stenosis (Group L). Patients with ST elevation ≥ 0.1 mV in the aVL lead on their admission ECG were included in the ST‐elevation group, and those with ST elevation < 0.1 mV were included in the non‐ST‐elevation group.

Results: The LVEF was greater in the non‐ST‐elevation group than in the ST‐elevation group (p<0.0001), and the LVEF in a whole group as follows: Group L LVEF>Group H LVEF>Group O LVEF (p = 0.0160). In the ST‐elevation group, LVEF was higher in Group L than in the other groups (p = 0.0251). There were three independent predictors of a reduced LVEF: ST‐elevation in aVL [odds ratio (OR): 3.38, p = 0.0044], IRL stenosis ≥ 90% (OR: 2.90, p = 0.0044), and the IRL occurring in the left anterior descending artery proximal to the first diagonal branch (OR: 6.31, p = 0.0024).

Conclusion: Left ventricular function was preserved, regardless of the severity of residual stenosis, in patients without ST elevation in aVL if the IRL was not totally occluded. In patients with ST elevation in aVL, LVEF was lower in patients with more severe stenosis, even if the IRL was patent.
Clinical and demographic determinants of heart rate variability in patients post myocardial infarction: Insights from the cardiac arrhythmia suppression trial (CAST)
Authors: Stein Phyllis K. , Kleiger Robert E. , Domitrovich Peter P. , Schechtman Kenneth B. , Rottman Jeffrey N.
Published: February 2009

Background: Clinical and demographic determinants of heart rate variability (HRV), an almost universal predictor of increased mortality, have not been systematically investigated in patients post myocardial infarction (MI).

Hypothesis: The study was undertaken to evaluate the relationship between pretreatment clinical and demographic variables and HRV in the Cardiac Arrhythmia Suppression Trial (CAST).

Methods: CAST patients were post MI and had ≥ 6 ventricular premature complexes/h on pretreatment recording. Patients in this substudy (n = 769) had usable pretreatment and suppression tapes and were successfully randomized on the first antiarrhythmic treatment. Tapes were rescanned; only time domain HRV was reported because many tapes lacked the calibrated timing signal needed for accurate frequency domain analysis. Independent predictors of HRV were determined by stepwise selection.

Results: Coronary artery bypass graft surgery (CABG) after the qualifying MI was the strongest determinant of HRV. The markedly decreased HRV associated with CABG was not associated with increased mortality. Ejection fraction and diabetes were also independent predictors of HRV. Other predictors for some indices of HRV included beta‐blocker use, gender, time from MI to Holter, history of CABG before the qualifying MI, and systolic blood pressure. Decreased HRV did not predict mortality for the entire group. For patients without CABG or diabetes, decreased standard deviation of all NN intervals (SDANN) predicted mortality. Clinical and demographic factors accounted for 31% of the variance in the average of normal‐to‐normal intervals (AVGNN) and 13–26% of the variance in other HRV indices.

Conclusions: Heart rate variability post MI is largely independent of clinical and demographic factors. Antecedent CABG dramatically reduces HRV. Recognition of this is necessary to prevent misclassification of risk in patients post infarct.
L‐Arginine reduces heart rate and improves hemodynamics in severe congestive heart failure
Authors: Bocchi Edimar Alcides , De Moraes Alvaro Vilella , Esteves‐Filho Antonio , Bacal Fernando , Auler José Otavio , Carmona Maria José , Bellotti Giovanni , Ramires Antonio Franchini
Published: February 2009

Background: Stimulated endothelium‐derived relaxing factor‐mediated vasodilation and conduit artery distensibility are impaired in congestive heart failure (CHF). L‐arginine could have a potentially beneficial role in CHF, acting through the nitric oxide (NO)‐L‐arginine pathway or by growth hormone increment.

Hypothesis: This study was undertaken to investigate the effects of L‐arginine on heart rate, hemodynamics, and left ventricular (LV) function in CHF.

Methods: In seven patients (aged 39 ± 8 years) with CHF, we obtained the following parameters using echocardiography and an LV Millar Mikro‐Tip catheter simultaneously under four conditions: basal, during NO inhalation (40 ppm), in basal condition before L‐arginine infusion, and after L‐arginine intravenous infusion (mean dose 30.4 ± 1.9 g).

Results: Nitric oxide inhalation increased pulmonary capillary wedge pressure from 25 ± 9 to 31 ± 7 mmHg (p < 0.05), but did not change echocardiographic variables or LV contractility by elastance determination. L‐arginine decreased heart rate (from 88 ± 15 to 80 ± 16 beats/min, p < 0.005), mean systemic arterial pressure (from 84 ± 17 to 70 ± 18 mmHg, p < 0.007), and systemic vascular resistance (from 24 ± 8 to 15 ± 6 Wood units, p < 0.003). L‐arginine increased right atrial pressure (from 7 ± 2 to 10 ± 3 mmHg, p < 0.04), cardiac output (from 3.4 ± 0.7 to 4.1 ± 0.8 l/min, p < 0.009), and stroke volume (from 40 ± 9 to 54 ± 14 ml, p < 0.008). The ratios of pulmonary vascular resistance to systemic vascular resistance at baseline and during NO inhalation were 0.09 and 0.075, respectively, and with L‐arginine this increased from 0.09 to 0.12.

Conclusion: L‐arginine exerted no effect on contractility; however, by acting on systemic vascular resistance it improved cardiac performance. L‐arginine showed a negative chronotropic effect. The possible beneficial effect of L‐arginine on reversing endothelial dysfunction in CHF without changing LV contractility should be the subject of further investigations.