bluuebunny/crossref_metadata_2025_split huggingface dataset:
The cardiovascular response at rest and during exercise in hypothyroid subjects to thyroxine substitution
Authors: Hylander B. , Ekelund L.‐G. , Rosenqvist U. 
Published: February 2009

AbstractRapid and intense thyroxine substitution can lead to heart failure and myocardial infarction in hypothyroid patients. We have analyzed the normalization of the circulatory system in hypothyroid subjects on a gradual thyroxine substitution. Fourteen hypothyroid patients were studied repeatedly with an orthostatic test and a standardized symptom‐limited exercise test during substitution. ST and T abnormalities were observed in 51 and 33%, respectively, before substitution. Many of these changes were normalized upon substitution at a dose level of 0.15 mg/d thyroxine. The pulse reaction to standing was enhanced early during substitution. The capacity to perform work, on the other hand, responded more slowly to thyroxine substitution, and was significantly increased only after six months of full substitution. This difference in the time course of recovery may be of clinical importance when substituting patients with hypothyroidism and ischemic heart disease.
Hypothyroidism, Raynaud's phenomenon, and acute myocardial infarction in a young woman
Authors: Sipilä R. , Viitasalo K. , Heikkilä J. 
Published: February 2009

AbstractWe describe an acute inferior myocardial infarction in a 29‐year‐old woman with normal coronary arteries. She has suffered from Raynaud's phenomenon in the fingers for several years. Manifest thyroid deficiency was discovered during hospitalization. A functional‐type link between hypothyroidism and myocardial infarction via vasospasm manifested as Raynaud's phenomenon is proposed as one possible etiology for the syndrome of myocardial infarction in young women.
Large V waves in the pulmonary capillary wedge pressure tracing without mitral regurgitation: He influence of the pressure/volume relationship on the V wave size
Authors: Pichard A. D. , Diaz R. , Marchant E. , Casanegra P. 
Published: February 2009

AbstractWe have previously demonstrated that a large V wave in the pulmonary capillary wedge tracing may occur in the absence of mitral regurgitation. This study evaluates the role of left atrial and pulmonary vein compliance on such a finding. We studied 11 patients with coronary disease, without clinical or angiographic mitral regurgitation. Heart rate, pulmonary capillary wedge mean, A and V waves, V‐wave slope, left ventricular and aortic pressures, cardiac output, and left atrial echo and apical phonocardiogram were recorded simultaneously. Preload was modified acutely by volume overload and by the administration of i.v. nitroglycerine. Volume administration induced a marked increase in V‐wave pressure (13.0±9.6 vs. 27.0±9.6 mmHg, p<0.05), without producing mitral regurgitation, and without appreciable change in left atrial dimension by echo (33.0±4.9 vs. 35.5±5.2 mm, NS), or stroke volume (101.7±26.2 vs. 97.8±34.3 ml, NS). An increase was also seen in the A wave (13.6±8.9 vs. 23.3±8.5 mmHg, p<0.05), pulmonary capillary wedge mean pressure (9.8±7.2 vs. 20.6±7.8 mmHg, p<0.05), and left ventricular diastolic pressure (7.4±5.5 vs. 14.6±6.3 mmHg, p<0.05). All values returned to baseline after nitroglycerine. The compliance of the left atrium/pulmonary veins decreased with increasing pulmonary capillary wedge pressures. With large filling volumes, a small stroke volume brings on a large pressure change, thus explaining the finding of large V waves in patients with elevated pulmonary capillary wedge pressure and without mitral regurgitation.
Assessment of valvular heart disease by doppler echocardiography
Authors: Pearlman A. S. , Scoblionko D. P. , Saal A. K. 
Published: February 2009

AbstractDoppler echocardiography provides direct hemodynamic data that are often complementary to those demonstrated by M‐mode and two‐dimensional echocardiographic imaging. This relatively new noninvasive technique has a number of important uses in patients with valvular heart disease. In both adults and children, Doppler measures of peak flow velocity through a stenotic valve allow accurate prediction of the pressure gradient across the valve, and the technique has particular promise for screening patients with suspected aortic or pulmonic stenosis. In patients with mitral stenosis but parasternal short‐axis images of limited quality, Doppler velocity measures can provide novel data about the pressure gradient and mitral orifice area. Doppler techniques can also provide direct evidence for or against the presence of valvular regurgitation, and several approaches allow clinically useful estimation of the extent of aortic, mitral, or tricuspid regurgitation. In patients with known disease of one cardiac valve, Doppler is accurate for evaluating the integrity of a second valve. Finally, Doppler techniques have great promise for defining the nature, and perhaps the severity, of suspected prosthetic valve malfunction. Hence, we believe that Doppler echocardiography should become a routine part of the noninvasive evaluation of patients with known or suspected valvular heart disease.
Salvage of an ischemic limb by laser angioplasty: Description of a New Technique
Authors: Ginsburg R. , Kim D.‐S. , Guthaner D. , Toth J. , Mitchell R. S. 
Published: February 2009

AbstractA 62‐year‐old male with severe claudication and rest pain of the left leg resulting from a totally occluded superficial femoral artery and a 95 % stenosis of the deep femoral artery was treated with laser angioplasty after attempts at surgical revascularization were unsuccessful. A 200 μU silica fiber was inserted through a catheter and advanced into the lesion using 2 watts of delivered energy from an argon laser source. The fiber was then withdrawn from the lesion using 7 watts of energy to enlarge the lumen. No complications occurred, and posterior tibial blood flow was reestablished, as shown by Doppler flow measurements and resolution of clinical symptoms. We report a new technique of transcatheter fiberoptic‐directed argon laser radiation (laser angioplasty) for the treatment of occlusive vascular disease.
Pulse generator failure due to blunt trauma
Authors: Gould L. , Betzu R. , Taddeo M. , Judge J. D. , Lee J. 
Published: February 2009

AbstractThis case describes a 69‐year‐old male who had a permanent pacemaker implanted for sick sinus syndrome. He was struck by a car with a resultant failure of the pulse generator. Trauma‐related failure of a pulse generator is a rare event. Its recognition is imperative in the overall management of the trauma patient.
The effects of grapefruit pectin on patients at risk for coronary heart disease without altering diet or lifestyle
Authors: Cerda J. J. , Robbins F. L. , Burgin C. W. , Baumgartner T. G. , Rice R. W. 
Published: February 2009

AbstractDietary intake of cholesterol has been linked to coronary heart disease. The effect of grapefruit pectin (Citrus paradisi) on plasma cholesterol, triglycerides, very low‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, high‐density lipoprotein cholesterol, and the low‐density lipoprotein:high‐density lipoprotein cholesterol ratio was studied. The study design was a 16‐week double‐blind, crossover (placebo or pectin) using 27 human volunteers screened to be at medium to high risk for coronary heart disease due to hypercholesterolemia. The study did not interfere with the subjects' current diet or lifestyle. Grapefruit pectin supplementation decreased plasma cholesterol 7.6%, low‐density lipoprotein cholesterol 10.8%, and the low‐density lipoprotein:high‐density lipoprotein cholesterol ratio 9.8%. The other plasma lipid fractions studied showed no significant differences. We conclude that a grapefruit pectin‐supplemented diet, without change in lifestyle, can significantly reduce plasma cholesterol.
Grapefruit pectin inhibits hypercholesterolemia and atherosclerosis in miniature swine
Authors: Baekey P. A. , Cerda J. J. , Burgin C. W. , Robbins F. L. , Rice R. W. , Baumgartner T. G. 
Published: February 2009

AbstractWe studied the effect of dietary grapefruit pectin on plasma cholesterol and the development of atherosclerosis in 18 miniature swine. Pigs were randomized to one of three diets: no added fat (I), added fat/cellulose (II), and added fat/pectin (III). Plasma cholesterol was measured monthly. Arteries were examined for atherosclerosis at the termination of the experiment. Pectin supplementation of an added fat diet resulted in a significantly lower average plasma cholesterol than did cellulose supplementation (168 mg/dl vs. 249 mg/dl, p<0.05). The pectin‐fed pigs also developed less atherosclerosis of their aortas (1.1% vs. 7.0%, p<0.05) and coronary arteries (2.9% vs. 26.2% cross‐sectional narrowing, p<0.05). Plasma cholesterol levels correlated with the severity of aortic (r=0.836) and coronary artery (r=0.735) atherosclerosis. We conclude that dietary grapefruit pectin supplementation inhibits hypercholesterolemia and appears to be proportionately protective against atherosclerosis.
Handgrip strength afterthe blalock‐taussig shunt: 14 to 34 year follow‐up
Authors: Zahka K. G. , Manolio T. A. , Rykiel M. J. F. , Abel D. L. , Neill C. A. , Kidd L. 
Published: February 2009

AbstractTo determine the long‐term functional impact of the Blalock‐Taussig (BT) shunt, we studied handgrip strength in 56 patients (10–28 years) following total repair of tetralogy of Fallot. Of the 56, 16 (29%) had a previous right BT shunt, 5 of 56 (9%) had a previous left BT shunt, and the remaining 35 patients either had a Potts shunt or primary total repair. The mean age at the time of right BT was 2.8 ±1.6 (SD) years, left BT 1.7±1.2 years, and total repair for all patients was 7.1 ±2.2 years. Mean age at the time of study was 26±9 years. Right‐and left‐handgrip strength were measured with a Jamar dynamometer, averaging the results of grip position 2,3, and 4 to accomodate variation in hand size. Since absolute values of hand strength were strongly associated with sex (p=0.006) and body surface area (p=0.016), we calculated the ratio of right‐hand to left‐handgrip strength (RL ratio). The RL ratios were: 0.98±0.13 (right BT), 1.21 ±0.11 (left BT), and 1.13±0.16 (no BT): (p=0.004 right BT vs. no BT, p=0.07 left BT vs. no BT, Wilcoxon rank sum test). Thus, although frequently clinically inapparent, handgrip strength tested many years post‐BT shunt is reduced on the side of the shunt.
The electrophysiological effects of intravenous magnesium on human sinus node, atrioventricular node, atrium, and ventricle
Authors: Rasmussen H. S. , Thomsen P. E. B. 
Published: February 2009

AbstractThe effects of intravenously (IV) administered magnesium chloride (MgCl) on electrophysiologic and electrocardiographic variables were studied in 13 patients undergoing a routine electrophysiologic assessment for clinical indications. An infusion of 12 mmol of MgCl was given during a 10‐min period and relevant electrophysiologic variables were determined before and after the infusion. Serum Mg levels increased from 0.78±0.03 (mean±SEM) before to 1.52±0.08 ms after the infusion (p<0.0001). Magnesium treatment caused a significant prolongation in PR interval (from 151±8 to 174±8 ms, p<0.001) as well as in QRS duration (from 90±4 to 101±6 ms, p <0.05). Likewise, intra‐atrial (PA) as well as atrioventricular (AV) nodal (AH) conduction times were significantly prolonged (from 33±3 to 46±3 ms, p<0.01, and from 85±6 to 94±6 ms, p<0.05, respectively). Mean effective and functional atrial refractory periods increased (from 228±8 to 256±10 ms, p<0.01 and from 292±9 to 320±11 ms, p<0.001, respectively), as did mean AV node functional refractory period (from 399±29 to 422±27 ms, p<0.02). No significant change occurred with regard to sinus node function (as estimated from heart rate, sinus node recovery time, and calculated sinoatrial conduction time) or ventricular refractoriness. It is concluded that IV Mg has several electrophysiologic effects that may be beneficial in the treatment/prevention of supraventricular tachyarrhythmias.
Sustained inotropic effects of a new cardiotonic agent. OPC‐8212 in patients with chronic heart failure
Authors: Asanoi H. , Sasayama S. , Kameyama T. , Ishizaka S. , Iuchi K. 
Published: February 2009

AbstractOPC‐8212, a newly synthesized noncatecholamine, nonglycosidic, orally effective inotropic agent, has been shown to exert a potent cardiotonic action in acute administration to patients with heart failure. However, its long‐term effect has not yet been established. Eight patients with dilated cardiomyopathy (New York Heart Association functional class II—III) were given a single dose of 60 mg of OPC‐8212 daily for4 to 8 weeks. OPC‐8212 produced symptomatic improvement in four patients. Though there were no detectable changes in arterial pressure and left ventricular end‐diastolic dimension, heart rate and end‐systolic dimension significantly decreased after administration of OPC‐8212. Baseline fractional shortening rose significantly and depression of shortening in response to acute pressor stress (afterload mismatch) was corrected after OPC‐8212. The end‐systolic pressure‐dimension relation was shifted to the left with a steeper slope. These findings indicate that the inotropic state was substantially enhanced by the drug. No adverse effects were observed in any patient. Thus, the drug appears to hold promise for the chronic treatment of patients with moderate congestive heart failure who are essentially asymptomatic at rest, but develop severe impairment of cardiac function in a stressed state.
Acute myocardial infarction due to coronary spasm associated with l‐thyroxine therapy
Authors: Hiasa Y. , Ishida T. , Aihara T. , Bando M. , Nakai Y. , Kataoka Y. , Mori H. 
Published: February 2009

AbstractA 63‐year‐old man with hypothyroidism is described. He had been receiving L‐thyroxine therapy following mitral valve surgery. About three weeks into the therapy regimen, he complained of severe retrosternal chest oppression. Electrocardiographic findings and laboratory data indicated a diagnosis of acute myocardial infarction due to the L‐thyroxine therapy. Emergency selective coronary angiography was performed. Comparing his coronary angiograms with those obtained before surgery indicated a severely spastic left coronary artery. We believe this is the first report of myocardial infarction due to coronary spasm, demonstrated by angiography associated with L‐thyroxine therapy.
Nicardipine, a new calcium channel blocker: Role for vascular selectivity
Authors: Pepine C. 
Published: February 2009

AbstractCalcium channel blockers are important drugs for the treatment of chronic stable angina. However, negative inotropic and dromotropic effects may limit their usefulness in patients with atrioventricular conduction abnormalities or left ventricular dysfunction. A new generation of calcium channel blockers will soon be available that have a more vascular selective action than currently available agents. Of the new agents, nicardipine has been most extensively studied. In experimental studies, nicardipine is more specific for vascular smooth muscle than for cardiac smooth muscle and for coronary than peripheral vasculature. In controlled trials, nicardipine exhibited efficacy and safety that was comparable to older calcium blockers or beta blockers. However, nicardipine was associated with minimal negative inotropic or dromotropic effects even in patients with existing left ventricular dysfunction. Thus, nicardipine may have an advantage over existing calcium channel blockers, especially in patients with underlying cardiac disease.
Does ergometric stress test induce a procoagulative condition in patients with previous myocardial infarction?
Authors: De SCALZI M. , Deleonardis V. , Becucci A. , Lusini C. , Brardi L. , Cinelli P. , Rafanelli D. , Cinotti S. , Filimberti E. , Longo G. 
Published: February 2009

AbstractA regularly scheduled physical training program seems to have antithrombotic effects. Moreover, the hemostatic changes occurring in patients with coronary artery disease during acute exercise have not been clearly elucidated. Since stress testing is routinely performed in clinical cardiology, it would be helpful to assess whether patients with coronary artery disease are exposed to acute coronary thrombosis during or soon after sustained physical exercise. This study was designed to evaluate the effect of acute physical exercise (stress test by bicycle ergometer) on blood coagulation in a group of patients with previous myocardial infarction, and to determine whether the antithrombotic therapy commonly administered favorably influences hemostatic equilibrium. Our results suggest that exercise testing is not harmful to patients with previous myocardial infarction in regard to hemostasis and fibrinolysis and that antithrombotic therapy reduces postexercise increase in platelets.
Peripheral percutaneous transluminal laser angioplasty in humans: In vitro investigations and clinical results with a novel laser catheter system
Authors: Neubaur T. , Klepzig M. , Heintzen M. P. , Richter E. I. , Zeitler E. , Strauer B. E. 
Published: February 2009

AbstractPercutaneous transluminal laser angioplasty has become an accepted method of treatment of peripheral arterial occlusive disease. To minimize the risk of arterial wall perforation during laser angioplasty, a novel laser catheter system was developed. in 113 obliterated postmortem human arteries the perforation rate was 0.9%. The mean degree of stenosis was reduced from 89±9% before, to 53±11% after laser irradiation. Clinical Nd:YAG laser angioplasty was performed in 19 patients suffering from peripheral arterial occlusive disease. The Fontaine stage improved in 16 patients; in no case did it deteriorate. The mean degree of stenosis was reduced by laser angioplasty from 91±12% to 31±19%. A further reduction down to 13±18% was achieved by subsequent percutaneous transluminal balloon angioplasty. The systolic Doppler ankle‐arm pressure gradient was improved from 0.58±0.26 to 0.89±0.25. in 7 patients microembolisms were detectable on the final angiogram. There was no acute reocclusion and no perforation. Within a follow‐up period of 12 months, four restenoses were diagnosed by digital subtraction angiography. On average, the Doppler index was 0.75±0.32.
Runaway pacemaker: A still existing complication and therapeutic guidelines
Authors: Mickley H. , Andersen C. , Hedemann Nielsen L. 
Published: February 2009

AbstractRunaway pacemaker is a rare, but still existing potential lethal complication in permanent pacemakers. Within 4 1/2 years, we saw two cases of runaway pacemaker in patients with multiprogrammable, VVI pacemakers (Siemens‐Elema, Model 668). In both cases a pacemaker‐induced ventricular tachycardia (rate 240–260 beats/min) was documented. One patient died. Runaway pacemakers must be exchanged as soon as possible. Until this can be accomplished, different emergency maneuvers should be tried. As documented in the cases presented, placing a magnet over the pacemaker may result in a lower, more physiological pacing rate. Reprogramming the pulse generator to a lower output or the use of external chest wall overdrive stimulation may also be successful, but these procedures require the presence of an adequate escape rhythm. If this is not the case or the former maneuvers have failed, an external pacemaker may be connected to the permanent pacing lead. Thereafter, the lead can be safely cut. As an alternative, a temporary transvenous pacing lead may be established prior to disconnecting the permanent pacing lead.
Implantable electrical devices in the management of tachyarrhythmias
Authors: De Belder M. A. , Camm A. J. 
Published: February 2009

AbstractElectrical therapy for tachyarrhythmias attempts to achieve one or more of three aims: a) prevention of tachycardia; (b) control of the hemodynamic effect of tachycardia; (c) termination of tachycardia. In practice, long term control of tachycardia in selected patients can be achieved with implantable devices which can automatically recognize and terminate tachycardias. Termination can be achieved with a number of pacing modalities. These pacing modalities are reviewed in this article and some guidelines to the choice of modality are given. Patients with supraventricular tachycardia are often more appropriately treated with drugs or surgery but some can be effectively treated with antitachycardia pacing. Some patients with ventricular tachycardia can be successfully treated with these devices but this group is at risk of tachycardia acceleration or degeneration in response to pacing. An implantable cardioverter‐defibrillator should be used as a backup in these patients. Present generation devices now incorporate antitachycardia pacing, low energy cardioversion, and higher energy defibrillation in the same unit.
Prediction of arrhythmic events in patients following myocardial infarction
Authors: Cripps T. R. , Camm A. J. 
Published: February 2009

AbstractThe value of techniques used to predict arrhythmic events (sudden cardiac death not preceded by reinfarction and spontaneous sustained ventricular tachycardia) after acute myocardial infarction is reviewed. A full clinical assessment allows the detection of patients with major infarction, present in the majority of those suffering arrhythmic events during follow‐up. More sophisticated noninvasive tests, including Holter monitoring, and the high gain, signal averaged ECG, add prognostic accuracy to clinical assessment in patients with major infarction but are by themselves nonspecific. Noninvasive assessment of autonomic function from baroreceptor sensitivity analysis and heart rate variability measurement may also provide useful prognostic information. The results of programmed ventricular stimulation studies in patients with recent acute infarction have been contradictory, though many of the disagreements can be explained by methodological differences. At best this technique is highly invasive, and probably adds little to what can be discovered from a thorough noninvasive assessment. The treatment to be adopted in those judged to be at high risk remains to be established, and this may include nonpharmacological modalities such as the implantable defibrillator and surgical ablation as alternatives to drug therapy.
Long‐Term prognosis in children with hypertrophic cardiomyopathy: An analysis of 37 patients aged ≤ 14 years at diagnosis
Authors: Romeo F. , Cianfrocca C. , Pelliccia F. , Colloridi V. , Cristofani R. , Reale A. 
Published: February 2009

AbstractThe relation of clinical, electrocardiographic, and hemodynamic findings at diagnosis to presenting features and prognosis of hypertrophic cardiomyopathy in childhood was evaluated in 37 consecutive patients below 14 years of age at time of diagnosis (24 males and 13 females, mean age 7 ± 4 years). A left ventricular outflow tract gradient (mean 42 ± 27 mmHg) was detected at cardiac catheterization in 13 (35%) patients. Clinical, electrocardiographic, and hemodynamic features in patients with and without a pressure gradient were similar. Patients who had moderate to severe functional limitation had a higher incidence of syncopal episodes (p < 0.001), lower ejection fraction (p < 0.01), raised pulmonary artery pressure (p < 0.001), and left ventricular end‐diastolic pressure (p < 0.01). During a follow‐up of 9.2 ± 5.1 years (range 2‐18), 9 (24%) patients died suddenly (2 with a recorded left ventricular outflow tract gradient). Univariate analysis showed that reduced ejection fraction (p=0.0001), syncopal episodes (p=0.003), increased left ventricular end‐diastolic pressure (p=0.03), and severe dyspnea (p=0.04) were associated with a poor prognosis. However, multivariate analysis revealed ejection fraction (p=0.0001) and syncopal episodes (p=0.0097) as independent predictors of survival. In conclusion, sudden cardiac death was common and was well predicted by the combination of left ventricular dysfunction and syncope at time of diagnosis.