bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural course of a prolonged pr interval and the relation between pr and incidence of coronary heart disease. A 7‐year follow‐up study of 1832 apparently healthy men aged 40–59 years
Authors: Erikssen J. , Otterstad J. E. 
Published: February 2009

AbstractDuring a baseline cardiovascular survey PR was measured in a strictly standardized way in 1832 men aged 40–59 years, free from coronary heart disease (CHD). Of 1758 men still alive, 1585 underwent an identical follow‐up study 7 years later. A total of 1570 were in sinus rhythm. The following findings were made: (1) Baseline and follow‐up prevalence of a prolonged PR (≥0.22 s) was identical (5.3 vs. 5.4%). (2) Only 60% of restudied men with a prolonged PR also had prolonged PR at follow‐up. (3) Only 1 of 98 with a prolonged baseline PR had a more advanced AV block at follow‐up, whereas an additional 4 had conditions which might influence the AV node (1 Bechterew' disease and 3 mild aortic valve stenosis). (4) The incidence of all CHD events found during the follow‐up study (CHD deaths, myocardial infarction, angina pectoris, and pathologic exercise ECGs) was moderately but significantly lower in men with a prolonged PR than among men with a PR ≤0.21 s. Thus a prolonged PR is rarely an indicator of impending, more severe conduction disturbances; it is mostly a benign, functional finding in middle‐aged men free from overt heart disease and is not positively associated with CHD. Rather PR may be moderately and inversely associated with latent CHD.
Effects of dobutamine on left ventricular performance and myocardial metabolic demands in patients with ischemic heart disease
Authors: Cote P. , Bourassa M. G. , Tubau J. F. , Enjalbert M. , Vandormael M. 
Published: February 2009

AbstractSixteen patients with coronary artery disease undergoing cardiac catheterization were studied. Eleven had previous infarcts and the patients were divided into two groups: In group I were 7 patients with no left ventricular dysfunction, no increase in ventricular size, or symptoms of congestive failure; group II included 9 patients with ventricular dysfunction, increased ventricular size, and 7 of the 9 had congestive failure. Each patient underwent a continuous infusion of dobutamine from 2.5 to 10 μUg/kg min‐1 with dosage increments of 2.5 μUg/kg at 15‐minute intervals. Systemic and coronary hemodynamic measurements were obtained at the end of the 5 and 10 μUg/kg min‐1 infusion doses. Left ventricular performance improved (higher cardiac index, left ventricular stroke work index and mean systolic ejection rate, and lower left ventricular end‐diastolic pressure), while heart rate, mean arterial pressure, and coronary sinus blood flow increased after dobutamine in the 16 patients. While patients in both groups had a rise in cardiac index, a reduction in left ventricular end‐diastolic pressure, an unchanged mean arterial pressure and a rise in coronary blood flow, only patients in group I had a significant increase in heart rate, and only patients in group II had significant increases in left ventricular stroke work index and mean systolic ejection rate, and a significant reduction in systemic vascular resistance. Left ventricular oxygen consumption did not increase significantly in either group. However, 5 patients showed a decreased myocardial lactate extraction after 10 μUg/kg min‐1 of intravenous dobutamine, 3 from group I and 2 from group II. These 5 patients had less ventricular dysfunction than patients with a normal lactate response to intravenous dobutamine. We conclude that the improvement in left ventricular performance observed after dobutamine administration in patients with ischemic heart disease is not usually associated with a major increase in left ventricular oxygen consumption or with marked aggravation of myocardial ischemia. This appears to be particularly true in patients with relatively severe left ventricular dysfunction.
A dose response study with oral prenalterol in patients with chronic congestive cardiac failure
Authors: Hendry W. G. , Comerford M. B. , Besterman E. M. M. 
Published: February 2009

AbstractPrenalterol is an orally active cardioselective beta agonist, with a long half‐life. Previous studies have confirmed its inotropic activity following intravenous infusion in patients with heart failure. It has little chronotropic activity and no significant arrhythmogenicity. We have studied the response to sustained‐release oral prenalterol given over four weeks at doses of 20, 40, 100, and 200 mg daily in 10 patients with New York Heart Association class II and III heart failure due to ischemic heart disease. All were in sinus rhythm and already receiving diuretics and digoxin. The drug was well tolerated and without side effects. Nine patients showed a dose‐related improvement in their exercise tolerance as measured on the treadmill, up to a dose of 100 mg daily, with a significant increase in estimated oxygen uptake. There was a dose‐related reduction in maximum heart rate, systolic blood pressure, and rate‐pressure product during exercise, which is suggestive of a reduction in myocardial oxygen consumption. We conclude that prenalterol improves exercise tolerance without any significant cardiovascular or other side effects, and produces a clinically relevant and sustained improvement in patients with chronic heart failure. M‐mode echocardiographic measurements of left ventricular dimension and function at rest did not show any change during the study.
Adverse reactions to protamine sulfate following cardiac surgery
Authors: Holland C. L. , Singh A. K. , Mcmaster P. R. B. , Fang W. 
Published: February 2009

AbstractWe report four patients who developed severe adverse reactions to protamine sulfate following cardiac surgery. Two types of reactions were seen. First, an immediate anaphylaxis which is a complement‐dependent IgG antibody‐mediated reaction. In the literature, 80% of patients who had similar reactions have had previous exposure to protamine. All patients adequately tested had positive skin tests and there is 6% mortality. The second reaction to protamine during cardiac surgery is characterized by delayed onset and profound vascular damage presenting as noncardiogenic pulmonary edema or total vascular collapse with prolonged hypotension and anasarca. These patients have negative skin tests and in our studies, no evidence of antibody mediated reaction, suggesting some other mechanisms may play a part. The mortality is high (30% of patients reported) and survivors have significant morbidity.
Long‐term oral treatment with high doses of verapamil in lone atrial fibrillation
Authors: Johansson P.‐A. , Bertil OLSSON S. 
Published: February 2009

AbstractIt has earlier been shown that verapamil given intravenously or orally in sufficiently high single doses, may result in regular ventricular rhythm in patients with atrial fibrillation. We have analyzed whether this effect of verapamil can be utilized in long‐term oral treatment. Eleven patients with lone atrial fibrillation were studied. Verapamil was given in gradually increasing doses from 40 mg three times a day to 320 mg three times a day, either alone or in combination with digoxin. Resting ECG was recorded and supine and standing blood pressures were measured on each dose level. When the patients were treated with verapamil alone, only a slight decrease in heart rate was noted, while during combined treatment with verapamil and digoxin a more marked heart rate decrease occurred with increasing doses of verapamil. The variation coefficient of the RR interval, a sign of ventricular regularity, decreased during verapamil treatment regardless of whether or not digoxin was also taken. A dose‐dependent blood pressure decrease was noted during verapamil treatment.Side effects were common and led to discontinuation of the attempted protocol in all patients. Three patients were unexpectedly converted to stable sinus rhythm. Five patients improved subjectively, with a marked decrease in the sensation of palpitations during intake of increasing doses of verapamil. The study indicates that chronic oral treatment with verapamil may sometimes relieve the subjective sensation of palpitations in patients with atrial fibrillation. Side effects do, however limit the value of this mode of treatment in the majority of patients.
Unusual form of bilateral partial anomalous pulmonary venous drainage
Authors: Bexton R. S. , Banim S. O. , Rees G. M. , Rees R. S. O. 
Published: February 2009

AbstractA 23‐year‐old man with known valvular pulmonary stenosis was found to have a very unusual form of bilateral partial anomalous pulmonary venous drainage. The venous drainage from the upper parts of both lungs was anomalous, draining from the left lung via a persistent left‐sided superior vena cava and from the right lung directly into the right atrial/right superior vena caval junction. The venous drainage from the lower parts of both lungs was normal. The embryological pathogenesis of the defect is discussed.
Competitive blood flow in the coronary circulation simulating progression of proximal coronary artery disease after saphenous vein bypass surgery
Authors: Miller W. P. , Dash H. 
Published: February 2009

AbstractWe report a case of competitive blood flow in the left coronary circulation after saphenous vein bypass grafting that resulted in the apparent progression of a proximal stenosis to total occlusion at coronary angiography. Repeat angiography with careful attention to catheter position and adequate injection of contrast agent demonstrated the actual anatomy and showed that there was no postoperative change in the native coronary circulation. The true incidence of progression of proximal coronary disease after saphenous vein bypass surgery is unknown, and reported figures may be falsely elevated because of unrecognized competitive flow patterns simulating obstruction.
Migration of retained pacemaker electrodes
Authors: Shaw R. J. , Chambers J. B. , Oldershaw P. J. 
Published: February 2009

AbstractTwo cases of migration of retained pacemaker electrodes are described. The first presented as an unusual cause of deep vein thrombosis while the second was asymptomatic and detected by routine chest x‐ray. Both made a good recovery, the first with surgery and the second with the fragment left in situ. A review of the world literature revealed only 13 other such cases. Of the total of 15 cases four are known to have died. In these patients no relationship was found between morbidity and the site of migration or associated infection and/or thrombosis. However surgical treatment appeared to be associated with a better prognosis.
Mitral valve prolapse related to geometrical changes of the heart in cases of progressive muscular dystrophy
Authors: Yazawa Y. 
Published: February 2009

AbstractThe significance of geometrical changes of the heart for the development of mitral valve prolapse (MVP) was studied by echocardiograms and chest x‐ray films in 58 cases of progressive muscular dystrophy (PMD). The incidence of MVP was significantly higher (p<0.001) incases where the thoracic spine was straight or lordotic compared with cases of kyphotic thoracic spine. The flattening of the thorax associated with deformation of the thoracic spine was correlated with the left atrial dimension and left ventricular dimension (r=0.62, r=0.37, respectively; p<0.001), and MVP developed predominantly in cases with flattened thorax and small left atrial or left ventricular dimensions. The left atrial and left ventricular dimensions were significantly smaller in cases with MVP compared to cases without MVP (p<0.001, p<0.005, respectively). When both the left atrial and the left ventricular dimension shortened to certain levels, MVP was observed in almost all cases. From these results, it was suggested that the portion from the left atrium to the left ventricle was pressed by the forward bending of the thoracic spine, and the subsequent geometrical changes of the mitral ring and the left ventricle could produce redundancy of the chorda tendinea of the mitral valve, resulting in the occurrence of MVP.
The exercise response in idiopathic dilated cardiomyopathy
Authors: Kirlin P. C. , Das S. , Zijnen P. , Wijns W. , Domenicucci S. , Roelandt J. , Pitt B. 
Published: February 2009

AbstractIn order to more clearly define the exercise response of idiopathic dilated cardiomyopathy (IDC), 20 patients in this study with strictly defined IDC were evaluated with radionuclide ventriculography and invasive hemodynamic monitoring. Severe cardiovascular impairment was present at rest, and peak supine exercise produced progressive left ventricular (LV) dilatation in both diastole and systole (mean±SEM from 172±14 to 212±22 ml/m2 at end‐diastole and from 137± 14 to 170±22 ml/m2 at end‐systole; both p<0.03). There were marked increases in LV and right ventricular filling pressure (from 17±2 to 36±3 mmHg and from 7±2 to 15±2 mmHg, respectively; both p<0.0001) and increased pulmonary artery pressure. Mean LV ejection fraction did not change significantly with exercise (22±2 to 23±3%; p>0.8), but individual patients demonstrated substantial variability. Cardiac output rose less than in normals and increases were brought about primarily by subnormal heart rate increases. High resting and exercise systemic and pulmonary vascular resistance were indicative of limited vasodilator reserve. Despite marked hemodynamic abnormalities, 10 of the 20 subjects had well preserved exercise capacity (≥ 12 min exercise duration). These patients as a group had significantly lower resting heart rate and higher exercise cardiac output and lower exercise systemic vascular resistance. However, they did not differ from the other patients with respect to resting LV function. Thus, the exercise response in IDC has specific characteristics that distinguish it from normal and from the exercise response of other causes of LV dysfunction. An interesting subset of patients with IDC has well preserved exercise capacity associated with greater chronotropic and vasodilator reserve. This finding suggests less sympathetic activation in these subjects.
Relationship between electrocardiographically estimated infarct size and clinical findings in anterior myocardial infarction
Authors: Herlitz J. , HJALMARSON Å. 
Published: February 2009

AbstractIn 292 patients with anterior myocardial infarction (MI) and no previous MI the electrocardiographically estimated infarct size was correlated with clinical findings during hospitalization and 3‐month follow‐up. Patients with ECG‐defined transmural MI had a higher incidence of different types of complications, such as congestive heart failure (CHF), hypotension, pericarditis, and a longer duration of hospitalization than patients with nontransmural MI. In a subgroup including 182 patients of the total series, a precordial map containing 24 electrodes was used. The sum of R waves (ΣR), the sum of Q waves (ΣQ), the number of Q waves, and ΣR‐ΣQ were calculated 4 days after arrival in hospital to estimate the size of infarction. There was generally a correlation between these ECG variables and different clinical findings, such as incidence of CHF, hypotension, pericarditis, and the duration of hospitalization. It is concluded that the ECG determined infarct size in anterior MI in a majority of patients correlates with the incidence of different types of complications in acute myocardial infarction. In the individual patient, however, the risk of developing complications cannot be predicted by ECG changes.
The inaccuracy of aortic valve systolic flutter as a screening test for significant aortic stenosis
Authors: Vacek J. L. , Phelix J. , Rycyna J. L. 
Published: February 2009

AbstractThe noninvasive assessment of the severity of aortic stenosis is difficult. A recent description of systolic flutter of aortic valve leaflets as a screening test for severe aortic stenosis was applied to a group of patients who had undergone catheterization. As opposed to the previous report, we found this an inaccurate, nonspecific, and insensitive aid for the differentiation of significant versus nonsignificant aortic stenosis; and feel that its validity should be studied further before wide application.
Aortic dilatation resulting in chronic aortic regurgitation and complicated by aortic dissection in a patient with turner's syndrome
Authors: Goldberg S. M. , Pizzarello R. A. , Goldman M. A. , Padmanabhan V. T. 
Published: February 2009

AbstractA patient with XO Turner's syndrome with a 12‐year history of progressive aortic root dilatation resulting in chronic aortic regurgitation is presented. Her case is unique in that it occurred in the absence of coarctation of the aorta, bicuspid aortic valve, or hypertension. Idiopathic dilatation of the aorta may be an additional risk factor to the development of aortic dissection in the setting of Turner's syndrome.
Blood flow measurements in the fetal descending aorta: Technique and Clinics
Authors: Tonge H. M. , Struijk P. C. , Wladimiroff J. W. 
Published: February 2009

AbstractA combination of two‐dimensional and realtime pulsed‐Doppler ultrasound provides a noninvasive method of measuring human fetal blood flow without side effects. By not altering the physiological conditions of the fetus, it minimizes external stimuli that might affect blood flow. However, due to the inaccessibility of the vessels under investigation, errors from the ultrasound technique arise and these are still being assessed. Studies of fetal blood flow suggest that the fetal circulation has a low peripheral resistance and that the increase in blood flow found with increasing gestational age is due predominantly to the increase in the actual dimensions of the fetal vasculature. Investigations in abnormal pregnancies, such as small‐for‐dates and those with cardiac arrhythmias have shown that the fetal cardiovascular system is capable of compensating efficiently to maintain normal physiological conditions, but only within the limits defined by the Frank Starling mechanism.
Echocardiographic assessment of left ventricular diastolic function in a normal population and a group of patients with myocardial hypertrophy
Authors: Bryhn M. 
Published: February 2009

AbstractIn order to study left ventricular diastolic function, digitized M‐mode echocardiograms of the free wall endocardium were analyzed. A population of 117 healthy individuals was compared with a group of 22 patients with myocardial hypertrophy due to aortic stenosis (AS), and a group of 21 with hypertrophic cardiomyopathy (HCMP). The time constant Te of endocardial retraction in normals (66±13 ms) differed significantly from Te in the patients (AS, 105±23 ms, p<0.001; HCMP, 113±31 ms, p<0.001). Peak velocity of endocardial retraction (peak neg. dEnd/dt, in the normals 8.6±2.7 s‐1) did not differ between normals and patients (AS, 7.0±2.3 s‐1; HCMP, 7.3±2.4 s‐1). Fractional shortening (FS) of the internal diameter, a parameter of left ventricular systolic function, tended to be higher in the AS patients than in the normal group, but was on the average significantly increased in the group of HCMP. However, most patients in the hypertrophic groups had FS within normal limits ±2 SD. The discrepancy between normal or supernormal systolic function and a pathological prolonged time constant Te in myocardial hypertrophy demonstrates the importance of diastolic parameters in left ventricular characterization. Te is a useful parameter of left ventricular diastolic function which can be provided noninvasively from echocardiographic M‐mode curves of the free wall endocardium.
Different effects of interventions suppressing free fatty acid metabolism on myocardial ischemia
Authors: Kahles H. , Hellige G. , Hunnemann D. H. , Junggeburth J. , Kochsiek K. 
Published: February 2009

AbstractWe studied the effects of different metabolic interventions, which stimulate oxidative myocardial carbohydrate metabolism, on ischemic stress during repeated coronary occlusions of three minutes in open‐chest dog hearts. Increase of glucose concentration in plasma and decrease of peripheral lipolysis by glucose‐insulin‐potassium (n=6) had no substantial beneficial effects on myocardial damage indicated by hemodynamic, electrocardiographic, and metabolic parameters. Infusion of lactate and pyruvate (10 mM, n=6) was detrimental. Only activation of pyruvate dehydrogenase by dichloroacetate (n=6) without influence on plasma osmolality reduced epicardial ST‐segment elevations (‐42%) and myocardial release of potassium (‐36%), phosphate (‐58%), and lactate (‐39%). Elevations of plasma osmolalities by 10 and 20 mOsm with the metabolically inert mannitol increased ECG changes, functional loss and release of potassium, phosphate, and lactate during ischemia in our model. It is suggested, that the oxygen‐saving potency of metabolic interventions can exert univocal beneficial effects in experimental and in clinical conditions only when systemic hyperosmolality and hypervolemia are avoided.
Acute myocarditis associated with transient marked myocardial thickening and complete atrioventricular block
Authors: Liao P.‐K. , Seward J. B. , Hagler D. J. , Driscoll D. J. 
Published: February 2009

AbstractA 17‐day‐old male infant with acute myocarditis developed complete heart block and cardiogenic shock. In addition, extensive concentric thickening of the left ventricular walls and diminution of the ventricular cavity were demonstrated by serial echocar‐diography. The echocardiographic findings mimicked a nonobstructive hypertrophic cardiomyopathy. However, the wall thickness gradually returned to normal, coincident with clinical improvement. This unusual myocardial thickening may have resulted from myocardial edema or cellular infiltration. Its relationship to high‐dose steroid therapy is unclear.
Left atrial myxoma associated with rheumatic mitral stenosis
Authors: Seagle R. L. , Nomeir A. M. , Watts L. E. 
Published: February 2009

AbstractThe rare occurrence of mitral stenosis and coexistent left atrial myxoma is reported. The patient had a 25‐year history of rheumatic heart disease and was referred for evaluation of progressive mitral stenosis without clinical suspicion of left atrial myxoma. The tumor was discovered by routine echocardiography in the course of evaluation of mitral stenosis. However, prior to surgery the patient experienced an episode of embolization of the tumor without major clinical sequelae. The utility of echocardiography in this case and in patients with mitral stenosis is discussed as well as the patient' spontaneous “cure.”
Hemodynamic and clinical findings after combined therapy with metoprolol and nifedipine in acute myocardial infarction
Authors: Emanuelsson H. , Herlitz J. , Hjalmarson Å. , Holmberg S. , Waagstein F. , Waldenströ A. , Waldenströ J. 
Published: February 2009

AbstractIn a double‐blind trial, 30 patients with suspected acute myocardial infarction with onset of symptoms within the previous 24 h were randomized to treatment with 10 mg nifedipine/placebo orally 4 times a day during hospitalization. All patients were given 15 mg metoprolol intravenously 20 min after the initial administration of nifedipine/placebo, and thereafter, 50 mg 4 times a day. The combined therapy resulted only in moderate changes in systolic blood pressure and heart rate compared with metoprolol alone. Three of the 15 patients in the nifedipine group versus 2 of the 15 in the placebo group were withdrawn because of hypotension and/or bradycardia. None was withdrawn because of congestive heart failure or A‐V block. It is concluded that the combination of nifedipine and metoprolol seems to be a relatively well‐tolerated combination in acute myocardial infarction.