bluuebunny/crossref_metadata_2025_split huggingface dataset:
High prevalence of repolarization abnormalities in children with simple ventricular ectopy
Authors: Miga Daniel E. , Case Christopher L. , Gillette Paul C. 
Published: February 2009

AbstractBackground: Premature ventricular contractions (PVCs) may occur in 0.3 to 2.2% of routine resting electrocardiograms (ECGs) in children with structurally normal hearts.Hypothesis: This study tests the hypothesis that repolarization abnormalities are present more frequently on the surface ECG in pediatric patients with benign ventricular ectopy.Methods: A retrospective study was performed examining 32 children with benign ventricular ectopy and structurally normal hearts. The surface ECG was carefully reviewed, concentrating on repolarization abnormalities as evidenced by a prolonged QTc, a prolonged JTc, and/or an abnormal T‐wave vector. QTc was calculated using Bazett's formula and considered prolonged if >440ms, and the JTc was calculated using a formula analogous to Bazett's formula and considered prolonged if >340 ms. The T‐wave vector was considered normal if between 0 to +90°, concordant with the frontal QRS axis and within 60°of the QRS axis. There were 13 females (41%) and 19 males (59%) with an average age of 9.1 years (range 1‐16.1 years). These patients were then compared with age‐ and gender‐matched controls. Fourteen of 32 study patients (44%) and 2 of 32 controls (6%) had evidence of repolarization abnormalities.Results: Using $cH2 analysis, there was a significant difference between groups (p=0.0005). No patient had an abnormal T‐wave vector and there were no other significant ECG abnormalities. There was no significant relationship between repolarization abnormalities and patient gender or age.Conclusion: A significant percentage (44%;p=0.0005) of children with benign ventricular ectopy have associated repolarization abnormalities as evidenced by a prolonged QTc and/or JTc. This finding suggests that children with “benign PVCs” may have repolarization changes indicative of underlying substrate abnormalities.
On‐line evaluation of systolic performance by densitometry in digital left ventriculography
Authors: Lehmkuhl Hans , Altstidl Robert , Machnig Thomas , Bachmann Kurt , Blunck Birgit , Barth Karl 
Published: February 2009

AbstractThe angiocardiographic evaluation of left ventricular end‐diastolic (LVEDV) and end‐systolic (LVESV) volumes and ejection fraction (EF) is routinely performed by the area‐length method (ALM) but may lead to erroneous results. Digital imaging in real time allows densitometric procedures of determining left ventricular (LV) performance to be applied alternatively. In this study, we present densitometric algorithms for the analysis of LVEDV, LVESV, and EF from digital image data, establish accuracy and reproducibility, and determine value and limitations in comparison with ALM in single‐plane 30°right anterior oblique (RAO) projection. A linear relationship between iodine depth and measured densities is mainly burdened with scatter radiation and beam hardening which reduce primary radiation and suppress iodine depth. However, facilities such as deconvolution and correction algorithms are capable of reducing these sources of error. In the present study, computer‐analyzed contrast images of iodine‐filled wedges and spheres showed a near‐linear relationship between iodine depth between 50‐100 mg/cm2 and measured densities. Contrast images of heart casts and LV an‐gio‐grams of 54 patients were obtained with a digital image acquisition and processing system, and evaluated by two in dependent observers. The phantom study resulted in significantly (p≤0.01) better densitometric standard errors of estimate for volumes [3.3 ml densitometry (DENS) vs. 8.9 ml (ALM)] and simulated EF [4.3% (DENS) vs. 7.8% (ALM)] than ALM. The standard error of estimate for the comparison between both methods was 8.4 ml for volumes and 7.5% for EF. Densitometric volumes tended to underestimate volumes calculated by ALM. The angiographic study of patients demonstrated significant correlations between both methods (LVEDV r = 0.78, LVESV r = 0.83, total volumes: r = 0.89;EF r = 0.88). The standard errors of estimate can be ascribed to systematic, method‐related errors of both DENS and ALM (LVEDV ± 28.9 ml, LVESV ± 23.4 ml, total volumes (EDV and ES V) ± 27.1 ml; EF ± 8.1 %). The intra‐ and interobserv‐er variability, respectively, exhibited significantly smaller (p ≤0.01 and p ≤0.05, respectively) standard errors of estimate for densitometric EF [4.6% (DENS) vs. 8.5% (ALM) and 7.1% (DENS) vs. 10.3% (ALM), respectively]. Inclined but not significant differences were found for LVEDV and LVESV. In conclusion, the data presented indicate that the calculation of LV volumes and EF in digital left ventriculography may be performed accurately by densitometric calculation in single‐plane 30°RAO projection. Minor underestima‐tions in densitometric volume determination may be anticipated in the evaluation of LV geometry.
Coronary artery and saphenous vein graft remodeling: A review of histologic findings after various interventional procedures—Part I
Authors: Waller Bruce F. , Orr Charles M. , Vantassel James , Fry Edward , Hermiller James , Grider Larry D. 
Published: February 2009

AbstractCatheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effects on the site of obstruction has been termed “remodeling.” Part I of this six‐part series focuses on mechanisms of remodeling after various interventional techniques, particularly balloon angioplasty.
Radiofrequency catheter ablation of a right atriofascicular (mahaim) and two atrioventricular (kent) accessory pathways in a single session
Authors: Hluchy Jan , Wieczorek Marcus , Tekiyeh Mohsen , Jurkovicova Olga , Sabin Georg V. 
Published: February 2009

AbstractThis report describes the case of a 19‐year‐old patient with Ebstein's anomaly, who had an unusual combination of a right atriofascicular (Mahaim) and two ipsilateral right atrioventricular (Kent) accessory pathways participating in three types of antidromic and orthodromic reciprocating tachycardias in the absence of retrograde conduction over the bundle of His‐atrioventricular node axis. All three pathways were ablated in a single session using temperature‐guided radiofrequency current.
Provocation of coronary spasm by dobutamine stress echocardiography in a patient with angiographically minimal coronary artery disease
Authors: Deligonul Ubeydullah , Armbruster Robert , Hajlu Admassu 
Published: February 2009

AbstractDobutamine stress echocardiography (DSE) has been widely used for the noninvasive diagnosis of obstructive coronary artery disease. The ST‐segment elevation during DSE has been reported as an infrequent event, caused by old myocardial infarction and/or critical coronary narrowings. The patient presented here was a 35‐year‐old man with a recent history of nonexertional chest pain. He had hyperc‐holesterolemia and a history of heavy smoking as risk factors. The patient developed ST‐segment elevation with chest pain during 40 mcg/min dobutamine infusion for the stress echocardiographic examination. Subsequent coronary angiograms revealed only mild coronary atherosclerosis. It is speculated that coronary spasm occurred in this patient as a paradoxical response to increased coronary blood flow with dobutamine administration.
Complications of pharmacologic stress echocardiography in coronary artery disease
Authors: Bigi Riccardo 
Published: February 2009

AbstractIn the last few years, pharmacologic stress echocardiography is emerging as a promising diagnostic tool with a favorable cost/benefit ratio. Its main clinical applications include the assessment of coronary artery disease, the identification of viable myocardium, and risk stratification before major vascular surgery. However, cardiac (arrhythmic, ischemic, or hemodynamic) as well as noncardiac complications have been reported, so that a risk/benefit analysis is advisable in view of the extensive introduction of this technique in the clinical arena. The most popular pharmacologic agents employed for stress echocardiography are dipyridamole, do‐butamine, and adenosine. A comparative analysis with exercise stress testing, the classical standard of reference of all ischemia‐provoking tests, confirms that in terms of safety and tolerability pharmacologic stress echocardiography may be considered a good alternative in patients unable to exercise maximally. No appreciable difference among the safety profiles of the most common pharmacologic agents has been found, but a careful evaluation of the risk/benefit ratio is advisable for any stressor in the individual patient by considering the relative importance of the expected diagnostic contribution and the pharmacodynamic impact of the test. Finally, adequate training of the operator and monitoring of the patient during stress and recovery are essential for getting optimal safety conditions.
Effect of the stress level achieved during symptom‐limited exercise technetium‐99m sestamibi myocardial tomography on the detection of coronary artery disease
Authors: Stratmann Henry G. , Younis Liwa T. , Wittry Mark D. , Amato Maryellen , Mark Alexander L. , Douglas Miller D. 
Published: February 2009

AbstractBackground: The stress level achieved during exercise thallium‐201 myocardial imaging may influence its sensitivity for detecting coronary artery disease (CAD). The effect of exercise adequacy on the accuracy of technetium‐99m sestamibi (MIBI) imaging has not been studied.Hypothesis: The study was undertaken to assess the effect of exercise level achieved on sensitivity for detecting CAD.Methods: A consecutive series of 250 patients (mean age 60 ± 10 years) with CAD by angiography underwent symptom‐limited exercise MIBI single‐photon emission computed tomography. Single‐vessel CAD was found in 66 patients, double‐vessel CAD in 84, triple‐vessel CAD in 80, and left main disease in 20.Results: No significant differences were found in sensitivities of an abnormal MIBI scan or a reversible defect among 102 patients reaching 85% of age‐predicted heart rate and 148 who did not (82 vs. 89% and 66 vs. 70%, respectively, p = NS). Patients (n = 128) able to exercise ≤6 min had a higher incidence of abnormal scans and reversible defects than 122 patients with a greater exercise duration (91 vs. 82% and 75 vs. 61 %, respectively, both p<0.05). Sensitivity of an abnormal MIBI scan for multivessel disease was greater than for single‐vessel disease in patients who achieved ≥85% of age predicted heart rate (91 vs. 59%, p<0.01) and in those who exercised >6 min (89 vs. 66%, p<0.01). No significant differences in the sensitivities of an abnormal MIBI study for multivessel versus single‐vessel CAD were seen in patients achieving lower peak levels of exercise. Sensitivity of ischemic ST depression was lower than that of MIBI tomography at all levels of exercise.Conclusions: The sensitivity of exercise MIBI tomography for angiographic CAD is relatively independent of the peak heart rate achieved. Exercise duration of >6 min is associated with a significantly higher MIBI abnormality rate than a duration of >6 min, possibly reflecting the effect of myocardial ischemic burden on exercise ventricular function. Regardless of level of stress or its duration, exercise MIBI tomography improves the sensitivity for CAD detection compared with stress‐induced ischemic ST depression.
Pneumococcal pericarditis—Out of sight, out of mind?
Authors: Mcmechan Stephen R. , Cochrane David , Jennifer Adgey A.A. 
Published: February 2009

AbstractPneumococcal pericarditis has been an uncommon condition in recent years. This report describes the case of a 57‐year‐old woman with sarcoidosis who presented with cardiac tamponade due to pneumococcal pericarditis. She responded to pericardiocentesis and intravenous antibiotic therapy. At 4‐month review, she remains well.
Myocardial contusion caused by a baseball
Authors: Mirukawa Masaru , Hirose Kunihiko , Mori Tatsuhiko , Kusukawa Jyunya , Tomioka Nobuyoshi , Watanabe Yutaka 
Published: February 2009

AbstractMyocardial contusion is a rare type of sports injury. We report a case of myocardial contusion caused by a baseball. In this patient, arrhythmias were induced by an exercise test 1 week after injury. That patients with myocardial contusion but without arrhythmias at rest need to be treated carefully is emphasized.
Ethanol sclerosis can be a safe and useful treatment for pericardial cyst
Authors: Kinoshita Yoshihisa , Shimada Toshio , Murakami Yo , Sano Kazuaki , Tanabe Kazuaki , Ishinaga Yuji , Kato Harumi , Murakami Rinji , Morioka Shigefumi 
Published: February 2009

AbstractWe report the case of a 41‐year‐old man with a pericardial cyst treated by percutaneous aspiration and ethanol injection. He was referred to our hospital because of elec‐trocardiographic abnormality. On admission, chest x‐ray revealed a large pericardial cyst in the right cardiophrenic angle. The cyst was examined by echocardiograpy, computed tomography, and cytological analysis of aspiration fluid from the cyst. Ethanol sclerosis was applied for treatment of the cyst, which had continued to increase in size. There was no recurrence of the cyst 6 months after the treatment. Percutaneous ethanol sclerosis can be the first choice of treatment for pericardial cyst.
The evolution of today's hospital emergency departments —Current problems and challenges
Authors: Mcintosh Henry D. 
Published: February 2009

AbstractThe announcement of the National Heart Attack Alert Program by the National Heart, Lung and Blood Institute in June of 1991 prompted leaders of the Florida Chapter of the American College of Cardiology to develop a statewide program to reduce the morbidity and mortality from acute myocardial infarctions within Florida. It became apparent that the success of such a program would require the prompt institution of thrombolytic agents or other revascular‐ization procedures in appropriate patients. No longer could the decision regarding institution of therapy await discussion by telephone and/or the arrival at the emergency department (ED) of the patient's primary care physician or cardiologist. Efforts to establish appropriate protocols for therapy revealed that many of the 25,000 or more physicians currently staffing the 5,600 or so EDs in this country were moonlighting residents or practitioners from a variety of specialties or subspe‐cialties with limited or no formal EM training. Furthermore, it was learned that there were in the entire country only about 800 postgraduate, year‐one Council for Graduate Medical Education accredited training positions. There were only 21 such training positions in the entire state of Florida. The reasons for these deficiencies are discussed and a challenge to correct this person power crisis is issued, not principally to the leadership of EM, but to the entire medical profession.
Cardiopulmonary determinants of functional capacity in patients with chronic heart failure compared with normals
Authors: Meyer Katharina , Westbrook Samuel , Schwaibold Matthias , Hajric Ramiz , Roskamm Helmut , Lehmann Manfred 
Published: February 2009

AbstractBackground: Patients with chronic heart failure (CHF) are characterized by abnormal gas exchange and ventilatory responses to exercise.Hypothesis: This study compares variables obtained from cardiopulmonary exercise testing in 35 patients with CHF with 35 age‐ and weight‐matched healthy subjects. A second goal was to obtain cardiopulrnonary variables measured at ventilatory threshold to distinguish patient changes from those of healthy subjects.Methods: Exercise testing was carried out using bicycle ergometry with ramplike protocol (work rate increments 12.5 W/min). Gas exchange and ventilation were measured breath by breath.Results: Compared with healthy subjects, the VO2 in patients was lower at identical work rates (p<0.004) and at ventilatory threshold (p<0.0001), and the slope of the VO2 curve during incremental exercise was flatter (p<0.05). With the exception of heart rate, the variables for VO2, VCO2, ventilation, O2 pulse, ventilatory equivalents for O2 and CO2, and Vd/Vt (physiologic deadspace to tidal volume ratio), as well as lactate differed significantly at identical work rates. With the exception of Vd/Vt, all cardiopulmonary variables showed significant differences in their slopes during exercise. By means of a discriminant analysis, VCO2 and ventilation proved to be the most distinguishing variables at ventilatory threshold between patients with CHF and healthy subjects.Conclusions: These results indicate the clinical usefulness of cardiopulmonary exercise testing when assessing functional impairment due to CHF. For treatment evaluation, not only VQ2 but also VCO2 and ventilation responses to exercise should be considered.
Coronary artery and saphenous vein graft remodeling: A review of histologic findings after various interventional procedures—Part IV
Authors: Waller Bruce F. , Orr Charles M. , Vantassel James , Peters Thomas , Fry Edward , Hermiller James , Grider Larry D. 
Published: February 2009

AbstractCatheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effects on the site of obstruction has been termed “remodeling.” Part IV of this six‐part series focuses on morphologic correlates of coronary angiographic patterns of remodeling after balloon angioplasty and discusses effects of angioplasty on adjacent, nondilated vessels.
The effect of atrial fibrillation and the ventricular rate control on exercise capacity
Authors: Ostermaier Ralf H. , Dalla Vecchia Laura , Lampert Steven , Ravid Shmuel 
Published: February 2009

AbstractBackground: Atrial fibrillation (AF) is a common cardiac arrhythmia, affecting approximately 1.5 million patients in the United States.Hypothesis: This study was designed to determine the effect of AF and the ventricular rate control during AF on cardiovascular performance as measured by exercise endurance on a standard Bruce protocol.Methods: Sixty‐three patients with AF who underwent exercise stress testing during both sinus rhythm and AF were analyzed. Heart rate, blood pressure, heart rate acceleration, exercise duration, and left ventricular (LV) systolic function were measured.Results: Atrial fibrillation resulted in a small but statistically significant decrease in exercise endurance (426 ± 180 vs. 402 ± 168 s, p < 0.05). The drop in exercise tolerance was consistent regardless of the underlying heart condition or adequate ventricular rate control during AF. Heart rate in AF was consistently faster than in sinus rhythm, at rest, and at peak exercise (63 vs. 79 beats/min and 125 vs. 149 beats/min, respectively, p < 0.001).Conclusion: Our analyses indicated that (1) the loss of atrioventricular synchrony had minimal effect on cardiovascular performance in patients with preserved LV function, (2) the decrease in cardiovascular performance was related to loss of atrioventricular synchrony but not to underlying heart disease or ventricular rate control, and (3) compensation for the loss of the atrial contribution was provided by consistently faster heart rate during AF.
Effect of amiodarone on qt dispersion in the 12‐lead standard electrocardiogram and its significance for subsequent arrhythmic events
Authors: Grimm Wolfram , Steder Ulrike , Menz Volker , Hoffmann JÜRgen , Maisch Bernhard 
Published: February 2009

AbstractBackground and hypothesis: QT dispersion, measured as interlead variability of QT intervals in the surface electrocardiogram, has been demonstrated to provide an indirect measurement of the inhomogeneity of myocardial repolarization. The purpose of the present study was twofold: (1) to analyze the effect of amiodarone on QT dispersion measured in the 12‐lead standard ECG, and (2) to examine the association between QT dispersion on amiodarone and subsequent arrhythmic events.Methods: To determine the effect of amiodarone on QT dispersion and its clinical significance for subsequent arrhythmic events, QT dispersion was measured in the 12‐lead standard electrocardiogram (ECG) in 52 patients before and after administration of empiric amiodarone for ventricular tachyarrhythmias.Results: QT intervals increased from 401 ± 44 ms before amiodarone to 442 ± 53 ms after amiodarone therapy, and rate corrected QT intervals (QTc) increased from 452 ± 43 ms to 477 ± 37 ms, respectively (p<0.01). QT dispersion, QTc dispersion, and adjusted QTc dispersion, which take account of the number of leads measured, were not significantly different before and after initiation of amiodarone therapy (58 ± 24 ms vs. 61 ± 26 ms, 68 ± 29 vs. 66 ± 26 ms, and 22 ± 8 vs. 22 ± 8 ms, respectively, p = NS). During 31 ± 25 months follow‐up after initiation of amiodarone therapy, arrhythmic events defined as sustained ventricular tachycardia, ventricular fibrillation, or sudden death occurred in 11 of 52 study patients (21%). QT dispersion, QTc dispersion, and adjusted QTc dispersion on amiodarone were not different between patients with and without arrhythmic events during follow‐up (65 ± 14 vs. 59 ± 29 ms, 73 ± 15 vs. 64 ± 28 ms, and 25 ± 6 vs. 21 ± 8 ms, respectively, p=NS).Conclusions: We conclude that (1) amiodarone increases QT intervals and QTc intervals during sinus rhythm but does not significantly change measures of QT dispersion; and (2) QT dispersion measured in the 12‐lead standard ECG after initiation of amiodarone therapy does not appear to be a useful marker for subsequent arrhythmic events.
Coronary artery and saphenous vein graft remodeling: A review of histologic findings after various interventional procedures—Part VI
Authors: Waller Bruce F. , Orr Charles M. , Vantassel James , Peters Thomas , Fry Edward , Hermiller James , Grider Larry D. 
Published: February 2009

AbstractCatheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effects on the site of obstruction has been termed “remodeling.” Part VI of this six‐part series focuses on atherectomy and restenosis tissue obtained by atherectomy procedures.
Clinical relevance of heart rate variability
Authors: Kautzner Josef , John Camm A. 
Published: February 2009

AbstractHeart rate variability (HRV) has recently become a popular noninvasive research tool in cardiology. Clinical assessment of HRV is frequently based on standard long‐term ambulatory electrocardiograms, whereas physiologic studies employ spectral analysis of short‐term recordings under controlled conditions. From a general point of view, HRV can be used in clinical practice to estimate (1) the integrity of cardiac autonomic innervation, (2) the physiologic status of cardiac autonomic activity, and (3) the vulnerability to various cardiac arrhythmias resulting from autonomic imbalance. Clinical relevance of HRV has been clearly demonstrated in only two clinical conditions: (1) impaired HRV can be used alone or in a combination with other factors to predict risk of arrhythmic events after acute myocardial infarction, and (2) decrease in HRV is a useful clinical marker for evolving diabetic neuropathy. Substantial advances of our knowledge are required to establish and promote clinical applications in other areas of clinical medicine. To accomplish this task, proper hypotheses should be studied and appropriate techniques selected.