bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chronobiologic vs. sphygmomanometric assessment of hypertension in a hospital setting
Authors: Portaluppi F. , Montanari L. , Capanna M. , Ferlini M. 
Published: February 2009

AbstractThe aim of this study was to assess the possible correlations between casual measurements and automatic monitoring analyzed with the chronobiologic technique in hospitalized hypertensive patients. Forty‐three patients (24 men and 19 women) with mild to moderate essential hypertension were studied in an open hospital ward 5 to 7 days after admission. Meal times, sleep times, and visiting hours were standardized. A clinical value of blood pressure was calculated as the arithmetic mean of three sphygmomanometric measurements taken in the morning (patient seated; 5‐min interval between measurements). Then, a basal value of blood pressure was considered as the lowest systolic and the lowest diastolic blood pressure among six sphygmomanometric measurements obtained every 5 min (patient supine). Noninvasive, automatic recording of blood pressure was also obtained every 15 min for 24 hours by a quasiportable oscillometric instrument. Blood pressure recordings were analyzed according to the “cosinor” method of Halberg. On average, clinical blood pressure was 160/96±14/10 mmHg, significantly higher (p<0.005) than either basal blood pressure (150/91±12/8 mmHg) or 24‐h recorded blood pressure mesor (144/88±13/9 mmHg). The differences were not entirely due to diurnal variations, since morning casual measurements were significantly higher than daytime average blood pressure. A chronobiologic assessment of hypertension in hospitalized patients is more representative of true blood pressure behavior, not only because of the multiple recordings but also because of the absence of an alarm reaction that may trigger a pressor response.
Determinants of end‐stage idiopathic dilated cardiomyopathy: A multivariate analysis of 104 patients
Authors: Romeo F. , Pelliccia F. , Cianfrocca C. , Barilla F. , Reale A. , Gallo P. , Cristofani R. 
Published: February 2009

AbstractOur purpose in this study was to investigate the correlation of clinical, electrocardiographic, hemodynamic, and histopathologic features at diagnosis with the long‐term prognosis in 104 patients with idiopathic dilated cardiomyopathy to determine which factors are the independent determinants of the end‐stage disease. During a mean follow‐up of 3.8±3.5 years, 35 patients (33%) died, 14 (13%) suddenly and 21 (20%) from congestive heart failure. Univariate analysis of survival curves disclosed that clinical and electrocardiographic variables at diagnosis were similar in survivors and non‐survivors. On the contrary, patients who subsequently died had higher mean right atrial pressure (p=0.0001), right ventricular end‐diastolic pressure (p=0.0061), mean pulmonary artery pressure (p=0.0001), and left ventricular systolic (p=0.0049) and end‐diastolic (p=0.0021) pressure than survivors. They also exhibited larger left ventricular end‐diastolic (p=0.0046) and end‐systolic (p=0.0027) volumes, lower ejection fraction (p=0.0001), and a greater proportion had severe mitral regurgitation (p=0.0095). Univariate analysis of histologic findings collected in a subgroup of patients referred since 1984 revealed a mild degree of myocellular hypertrophy to be associated with a poor prognosis (p=0.0217). Multivariate analysis selected only mean right atrial pressure (p=0.0022), ejection fraction (p=0.0089), and endsystolic volume (p=0.0265) as independent determinants of cardiac death. Our results suggest that cardiac catheterization is mandatory for risk stratification of patients with idiopathic dilated cardiomyopathy, since it allows the assessment of hemodynamic, angiographic, and histopathologic features helpful in identifying patients with a poor prognosis.
Hemodynamic and antianginal effects during rest and exercise of intravenous isradipine, a new dihydropyridine calcium antagonist
Authors: Burger W. , Neidel S. , Kober G. 
Published: February 2009

AbstractIn an open randomized study, hemodynamic and antianginal effects of nifedipine and the new dihydropyridine derivative isradipine were compared in patients with stable, angiographically confirmed coronary heart disease. Right heart hemodynamics, systemic arterial blood pressure, ECG, and drug plasma concentrations were measured before medication at rest and exercise, after infusions of increasing doses at rest, and again after treatment at rest and exercise. A linear relationship between serum concentrations and cumulated dosages was obtained for both drugs. At rest, both drugs significantly increased cardiac output and heart rate. The reduction of arterial blood pressure was significantly greater after isradipine (systolic from 148±3 to 104±3 mmHg; diastolic from 90±4 to 58±2 mmHg) than after nifedipine (systolic 149±6 to 125±4 mmHg; diastolic 92±4 to 76±3 mmHg). The minimal effective plasma level of isradipine regarding blood pressure reduction was estimated at 5 ng/ml (nifedipine: 10–25 ng/ml). During exercise both medications significantly reduced mean pulmonary artery pressure (isradipine: 40±3 to 20±1 mmHg, nifedipine: 37±4 to 22±1 mmHg), pulmonary artery wedge pressure (isradipine: 23±3 to 10±1 mmHg, nifedipine 24±3 to 14±1 mmHg), and diastolic arterial pressure (isradipine: 103±3 to 73±4 mmHg, nifedipine: 99±3 to 91±2 mmHg), whereas systolic pressure was reduced by only isradipine (189±4 to 147±5 mmHg). Neither medication significantly changed electrocardiographic ST depression during exercise. There was a high rate of painless ST depression (nifedipine 1/8, isradipine 4/8) during the drug dosing and increased ST depression during exercise. This phenomenon can be explained by either coronary steal or by ST depression of unknown origin after dihydropyridine treatment.
Combination of sensors to provide optimal pacing rate response
Authors: Paul V. , Garratt C. , Camm A. J. 
Published: February 2009

AbstractPreviously, single‐chambered rate‐adaptive and dual‐chamber pacemakers have been considered as alternative methods of providing rate response. Neither can adapt to changing circumstances and each has its own benefits and limitations. The development of units combining both facilities expands the range of conditions for which atrioventricular sequential pacing is possible and will ensure appropriate and adequate rate response at all times. At present, change in pacing mode is dependent on physician programming, but future generations will have the ability to diagnose the intrinsic rhythm and then prescribe automatically the pacing modality of choice.
Does nitroglycerin induce heparin resistance?
Authors: Lepor N. E. , Amin D. K. , Berberian L. , Shah P. K. 
Published: February 2009

AbstractWe studied the possibility that intravenous nitroglycerin may produce heparin resistance both in vitro and prospectively in a group of 10 patients following coronary angioplasty. Nitroglycerin in physiologic to pharmacologic concentrations (41‐250 μg/ml) did not produce heparin resistance in vitro as measured by activated partial thromboplastin time and thrombin time. The maximum reduction in activated partial thromboplastin time was 7%. In patient studies, the activated partial thromboplastin time at baseline on heparin alone (93±22 s) was not significantly different (p=0.61) from activated partial thromboplastin measured upon addition of nitroglycerin (94±27 s) or 30 min following cessation of the nitroglycerin infusion while continuing the same dose of heparin (91±24 s). We conclude that intravenous nitroglycerin does not induce heparin resistance in vitro or in patients during short‐term administration.
Assessment of the intracardiac left to right shunts with a single scintillation probe
Authors: Tendera M. , Bartoszewski A. , Foremny J. , Salamon A. , Wodniecki J. , Malecka‐Tendera E. 
Published: February 2009

AbstractIn order to assess the accuracy of pulmonary time‐activity curves obtained at bedside with a single scintillation probe and Technetium‐99m‐labelled erythrocytes, pulmonary to systemic flow ratio (Qp:Qs) was calculated for radionuclide and hemodynamic investigations in 104 patients with suspected intracardiac left to right shunts. Cardiac catheterization confirmed the presence of shunts in 76 patients. Pulmonary time‐activity curve was 100% sensitive, 88% specific, and 96% accurate in detecting the shunt. Correlation between the radionuclide and hemodynamic Qp:Qs was excellent (r=0.93). Results were classified in four quantitative categories according to the Qp:Qs values. In 76 patients (73%) radionuclide and hemodynamic data fell in the same category. We conclude that radionuclide pulmonary time‐activity curves generated with a scintillation probe is a reliable method in quantitative assessment of intracardiac left to right shunts.
Increased Ca2+ influx into platelets induced by thromboxane A2 analog in patients with ischemic heart disease
Authors: Kobayashi N. , Okumura K. , Hashimoto H. , Ito T. , Satake T. 
Published: February 2009

AbstractWe compared platelet aggregation and intracellular free calcium concentrations ([Ca2+]i) following stimulation with STA2, an analog of thromboxane A2 between patients with ischemic heart disease (IHD) showing significant stenosis in coronary angiograms and controls. In the presence of extracellular calcium, platelet aggregation and intracellular Ca2+ increase were enhanced by STA2 stimulation in a dose‐dependent fashion and were higher in the IHD patients than in the controls. However, in the absence of extracellular calcium, no difference in intracellular Ca2+ increase was observed due to its total dependence on release from intracellular stores. These results suggest that thromboxane A2 increases platelet intracellular Ca2+‐inducing aggregation, and this increase and aggregation, which is enhanced by thromboxane A2 in IHD patients, is due to promotion of Ca2+ influx by thromboxane A 2. IHD patients appear to have an abnormality in the platelet membrane which may explain such thromboxane A2‐dependent increased permeability to Ca2+.
Mesothelioma of the atrioventricular node and congenital complete heart block
Authors: Subramanian R. , Flygenring B. 
Published: February 2009

AbstractCongenital complete heart block (CCHB) has heterogeneous etiologies. It may occur as an isolated entity with no associated congenital cardiac malformations and is difficult to diagnose even with modern technology. Mesothelioma of the atrioventricular (AV) node is a benign tumor that causes CCHB. The occurrence of this tumor is rare, and a definitive diagnosis of the entity is made only at autopsy. The conduction disturbance caused by the mesothelioma is potentially treatable and should be considered in the differential diagnosis of CCHB. We present a case report of a 38‐year‐old female with CCHB caused by such a tumor. Clinical diagnosis and treatment of CCHB are reviewed.
Doppler echocardiographic assessment of transmitral gradients and mitral valve area before and after mitral valve balloon dilatation
Authors: Dev V. , Singh L. S. K. , Radhakrishnan S. , Saxena A. , Shrivastava S. 
Published: February 2009

AbstractThis is a comparative study of 60 sets of observations of mitral valve end‐diastolic gradient, mean diastolic gradient, and mitral valve area obtained by Doppler echocardiography and cardiac catheterization. The studies were performed in 28 patients, 16 of whom underwent mitral valve balloon valvuloplasty. These 16 patients had studies performed before, immediately after valvuloplasty, and one week later. Thus 28 studies were performed before or without valvuloplasty (Group I) and 32 after valvuloplasty (Group II). The time interval between Doppler echocardiography and cardiac catheterization was less than 24 hours in 44 studies and 24 to 72 hours in 16 studies. In Doppler echocardiography the gradients were obtained by simplified Bernoulli's equation and the mitral valve area by pressure half‐time method. There was excellent correlation between end‐diastolic gradients (r=0.96, p<0.001) and mean diastolic gradients (r=0.92, p<0.001) measured by the two techniques. A statistically significant correlation also existed in the mitral valve area values (r=0.53, p<0.005). On separate analysis Group I showed excellent correlation for all three variables (r values of 0.90, 0.87, and 0.82 for end‐diastolic gradients, mean‐diastolic gradients, and mitral valve area, respectively). Group II also showed excellent correlation of end‐diastolic gradients (r=0.80) and mean diastolic gradients (r=0.87), but poor correlation of the mitral valve areas (r=0.17; p=NS) by the two techniques. Doppler echocardiography can accurately measure transmitral gradients both before and after valvuloplasty. The mitral valve area derived by Doppler echocardiography using the pressure half‐time method was unreliable 1 to 7 days after mitral valvuloplasty in our experience. The presence of atrial fibrillation (n=8), mild aortic regurgitation (n=6), and mitral valve calcification (n=5) did not seem to alter the accuracy of Doppler echocardiography in assessing the severity of mitral stenosis.
Prognostic significance of postinfarction arrhythmias and biventricular dysfunction under stress
Authors: Fridrich L. 
Published: February 2009

AbstractThe prognostic relevance on mortality of right ventricular dysfunction in comparison with left ventricular function during stress, complex arrhythmias detected by Holter monitoring, and variables of exercise performance, was evaluated via a retrospective follow‐up of more than four years for cardiac mortality of all patients in the chronic stage after myocardial infarction who were referred serially during a one‐year period to stress radionuclide‐ventriculography and 24‐h Holter monitoring. A sample of 47% (213) of all patients admitted after myocardial infarction to the rehabilitation center during 1983 was investigated by scintigraphic stress testing and Holter monitoring and were followed up. Subsequent medication and invasive therapeutic interventions were documented. The mortality during a mean follow‐up period of 3.9 years in 213 patients (mean age, 56 years) was 14.6%. Significantly decreased values of left and right ventricular ejection fractions during stress scintigraphy (38±14 versus 50±15%, p=0.000 and 45±13 versus 54±11%, p=0.001, respectively) were revealed in the cardiac deceased patient cohort compared with the remainder. Complex arrhythmias during Holter monitoring occurred twice as often (62 vs. 34%, p=0.0059) in later deceased patients. Lifetable analysis demonstrated that patients with biventricular stress dysfunction had a significantly worse survival prognosis than those with monoventricular dysfunction. Multivariate nonlinear Cox survival analysis revealed that left and right ventricular ejection fraction during stress and arrhythmias were of independent prognostic significance compared with multiple clinical variables including those of exercise performance. Thus, apart from left ventricular dysfunction and arrhythmias, scintigraphically assessed right ventricular stress dysfunction is a further marker of poor prognosis after myocardial infarction. This reflects the previously neglected pathophysiologic significance of right ventricular performance in patients after myocardial infarction.
Structure and function of contractile proteins in human dilated cardiomyopathy
Authors: Wiegand V. , Ebecke M. , Figulla H. , Schüler S. , Kreuzer H. 
Published: February 2009

AbstractThe pathogenesis of reduced systolic left ventricular function in dilated cardiomyopathy is yet unclear. To analyze a possible involvement of contractile protein, function and structure of left ventricular myofibrils were examined in hearts of patients with advanced cardiomyopathy undergoing heart transplantation and in normal control hearts (from renal transplant donors). Myosin and actin content of the left ventricular myocardium was slightly reduced in cardiomyopathic hearts. Myofibrillar polypeptide composition was determined using two‐dimensional electrophoresis and immunoblotting. No differences in constituting polypeptides were apparent, including Z‐line proteins and proteins of the endosarcomeric lattice. M‐line‐bound creatine kinase was identical in both groups. Further, basal and maximal myofibrillar adenosine triphosphatase (ATPase) activities were unaltered in dilated cardiomyopathy. The structure of purified myosin was identical in both groups by the following criteria: electrophoretic mobility of native myosin, identical pattern of light chains after isoelectric focusing, identical cleavage peptides of myosin's heavy chain, and identical patterns after immunoblotting of heavy chain cleavage peptides using polyclonal antibodies generated against myosin from normal and cardiomyopathic ventricles. Ca2+‐activated, K+‐EDTA‐activated and actin‐activated myosin ATPase activities were identical in control and cardiomyopathic hearts. A structural alteration or functional defect of myofibrils does not seem to be primarily involved in the pathogenesis of reduced myocardial contractility in dilated cardiomyopathy.
Some aspects of the wideband recording of the electrocardiogram
Authors: Mor‐Avi V. , Akselrod S. 
Published: February 2009

AbstractThe physiological mechanisms responsible for the high frequency components of the electrocardiographic signals in different frequency ranges are still unknown. These components have been studied in the frequency domain as well as in the time domain. Numerous clinical and experimental studies have focused upon the incidence and interpretation of high frequency notches and slurs under different conditions in the myocardium. However, the analysis of the high frequency components appeared to be tedious and imprecise, and the interpretation of its results difficult and controversial, and strongly dependent upon empirically determined standards which still require thorough evaluation. Digital methods for processing electrocardiographic signals developed during the last decade have given rise to a variety of fast and reliable approaches for analyzing the information carried by the electrocardiogram. Many researchers have applied such methods to various clinical situations in human studies and to different kinds of interventions in animal studies. These developments prompted us to review research in the field of wideband recording of the electrocardiogram and to briefly discuss some of the aspects that still require elucidation.
Catheter ablation using radiofrequency energy
Authors: Borggrefe M. , Hindricks G. , Haverkamp W. , Breithardt G. 
Published: February 2009

AbstractRecently, transvenous catheter ablation using radiofrequency impulses has been applied in experimental animals as well as in humans. This review describes the biophysics, mechanisms, and tissue effects of radio‐frequency alternating current. Ablation of the AV‐junction has been performed in experimental studies as well as in a growing number of patients. Complete AV‐block or modification of the AV conduction by RF‐current application can be achieved in about 45‐65% of patients. Presently about 50% of patients with rightsided accessory pathways can be successfully managed using radiofrequency impulses. Certain limitations exist using a biopolar “epi‐endocardial” electrode configuration forleftsided accessory pathways. Only few studies are available concerning the use of RF ablation of ventricular tachycardia foci. As most experimental investigations were carried out in structurally nondiseased myocardium, the use of this new technique in fibrotic or scarred tissue warrants further studies. Radiofrequency catheter ablation seems to be feasible and relatively safe for the treatment of otherwise drug‐refractory supraventricular arrhythmias; further studies are needed to assess the safety and efficacy in patients with drug‐refractory ventricular tachyarrhythmias.
Two unusual manifestations of aortic aneurysms
Authors: Tejada E. , Becker G. J. , Waller B. F. 
Published: February 2009

AbstractPain and pulsation are common presenting features of aortic aneurysms. Massive hematemasis and ureteral obstruction represent rare clinical presentations. This report describes a patient with massive hematemesis in whom a thoracic aneurysm ruptured into the esophagus, and a second patient in whom a large abdominal aortic aneurysm caused bilateral ureteral obstruction.
Fatal massive pulmonary hemorrhage complicating mitral stenosis
Authors: Leung W.‐H. , Lau C.‐P. , Wong C.‐K. , Cheng C.‐H. 
Published: February 2009

AbstractMitral stenosis is a well known cause of hemoptysis; however, sudden death due to fatal massive pulmonary hemorrhage is an extremely rare complication. In this report, we describe a 28‐year‐old female with severe mitral stenosis who died suddenly due to such complication. A review of the literature shows such complication is extremely rare and unpredictable. We recommend that patients with severe mitral stenosis and history of hemoptysis be considered as candidates for early surgical intervention.
Hereditary long qt syndrome in the postoperative cardiac patient
Authors: Klitzner T. 
Published: February 2009

AbstractThe purpose of the present article is to evaluate the diagnostic implications of the long QT syndrome presenting in postoperative cardiac patients. Diagnosis of long QT syndromes may be complicated by an inability to measure the QT interval correctly due to postoperative electrocardiographic changes such as right bundle‐branch block. For this reason, a study of the effect of right bundle‐branch block on the QT interval was undertaken. Electrocardiograms of 17 randomly selected patients undergoing a right ventriculotomy for repair of tetralogy of Fallot were evaluated for QT prolongation pre‐ and postoperatively. Preoperatively, no patient demonstrated QT interval prolongation. After surgery, however, right bundle‐branch block created an apparent prolongation of the QT interval in 9 of the 17 patients (53%). These results suggest that in postoperative cardiac patients QT prolongation and familial long QT syndromes may be difficult to diagnose. It is, therefore, important to exclude the long QT syndrome in patients with ventricular tachycardia even if a more obvious explanation such as previous cardiac surgery is present. Usually a careful family history and preoperative electrocardiogram are all that is required.
Hypertension and sports activities: Institutional experience
Authors: Lehmann M. , Dürr H. , Merkelbach H. , Schmid A. 
Published: February 2009

AbstractFindings of 185 patients and 271 control subjects are presented for the assessment of work capacity in hypertensive individuals (primary hypertension); an attempt at classification by hypertensive stage is seen as an essential presupposition. The subdivision into three stages recommended by the Experts' Commission of the WHO places the effects of hypertension on the organism, especially on the heart, in the focal point. This appears justified from a prognostic, pathophysiological, and therapeutic point of view. Hemodynamics in the examined patients undergo increasing impairment in relation to the stage of hypertension with a decrease in maximum cardiac index and work capacity and an increase in myocardial oxygen requirement. Initially, only the diastolic cardiac function is impaired; however, in advanced stages, the systolic function of the heart is impaired as well. Evaluation of work capacity is usually possible from a cardiac point of view by means of noninvasive echocardiographic and spiroergometric methods. The mass/volume ratio of the left cardiac ventricle and the relationship between left ventricular muscle mass (or volume) and work capacity are especially important. Both experience characteristic changes depending on the stage of hypertension and thus permit precise determination of work capacity, progress controls, and delineation from physiological cardiac hypertrophy (athletic heart).