bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nuclear Cardiology, Current Applications in Clinical Practice
Authors: Niemeyer M.G. , van der Wall E.E. , Kuijper A.F.M. , Cleophas A.T. , Pauwels E.K.J. 
Published: July 2008

The clinical applications of nuclear cardiology have rapidly expanded since the introduc tion of suitable imaging cameras and readily applicable isotopes. The currently available methods can provide useful data on estimates of ventricular function and detection of myocardial ischemia for adequate patient management. Two standard procedures are routinely used: (1) myocardial perfusion scintigraphy, eg, with thallium 201; and (2) radionuclide angiocardiography by using technetium 99m-labeled red blood cells. Myocardial perfusion scintigraphy provides information on regional viability and estimates regional myocardial perfusion by measuring regional tracer activity. Thallium 201 is the agent used for noninvasive assessment of myocardial perfusion and for improving the results of exercise electrocardiography. Alternative tests, such as pharmacologic stress testing with dipyridamole, have been proposed as a reliable substitute for exercise testing. Additional quantitative analysis and computed tomography have increased the sensi tivity and specificity of thallium scintigraphy. Radionuclide angiography techniques are used for the noninvasive evaluation of cardiac function, right and left ventricular function, and wall motion abnormalities. As in perfusion scintigraphy, radionuclide angiography has proven its value for the detection of coronary artery disease (CAD). Abnormal regional wall motion abnormalities are specific for CAD.
Angiotensin II Pressor Activity Depends on Medial and Lateral Anterior Hypothalamic Pathways
Authors: Kawabe Hiroshi , Lopes Oswaldo U. , Brosnihan Karen B. , Saruta Takao , Ferrario Carlos M. 
Published: July 2008

The preoptic region of hypothalamus was disconnected from caudal structures with two different-size knife cuts in rats to investigate the pathway responsible for the effects of intracerebroventricular (ICV) and intravenous (IV) angiotensin II (ang II) on blood pressure and arginine vasopressin (AVP) release. Seven days after surgery ICV ang II (125 ng) in sham-operated (sham) rats increased mean arterial pressure (MAP) (+23 ±3 mmHg) and decreased heart rate (HR) (-58 ± 5 beats/minute). However, ICV ang II had no effect on MAP or HR of rats with a large (preoptic-hypothalamic disconnection) cut. Both the pressor response (+12 ±2 mmHg) and the bradycardia (-39 ±6 beats/minute) were significantly reduced by a small (medial preoptic-hypothalamic disconnection) cut. The increased plasma AVP to ICV ang II in sham rats (9.8 ±3.6 pg/mL) was abolished in large-cut rats and attenuated in small-cut rats (3.2 ±0.7 pg/mL). IV bolus injection of ang II (125 ng) in sham rats increased MAP by 43 mmHg, whereas large-cut rats showed a blunted (25%) pressor response. The pressor response to IV infusion of ang II (8 ng/20 μL/minute for 15 minutes) was diminished in large-cut rats (+4 ±1 mmHg) as compared with that in sham rats (+ 19 ± 2 mmHg). Both cuts transected the projection between the periventricular tissue surrounding the anteroventral third ventricle and supraoptic nucleus, but the supraoptic-neurohy pophyseal pathway was severed only by the large cut. By examining the location of microknife cuts, the authors conclude that the connectivity of the preoptic region with more caudal sites is necessary for the expression of the central and peripheral pressor activity of ang II, probably involving a key role of supraoptic nucleus and its connections.
Transcutaneous Oxygen Tension and Doppler Ankle Pressure During Upper and Lower Body Exercise in Patients with Peripheral Arterial Occlusive Disease
Authors: Liu Yuefei , Steinacker Jürgen M. , Stauch Martin 
Published: July 2008

The effects of upper and lower body exercise on blood supply to the lower extremi ties were investigated in patients with peripheral arterial occlusive disease (PAOD) by measurements of transcutaneous oxygen tension (tcPO2) and Doppler ankle pressure (DAP). Twenty patients with PAOD (PAOD group) and 10 subjects without PAOD (control group) performed treadmill test (TT), recumbent cycle ergometry (CE), and rowing ergometry (RE) with a fixed seat. The tcPO2 was registered on the calf and DAP was measured at the end of each step of CE and RE. The walking distance in TT of the control group was not limited (> 1000 m), whereas that of the PAOD group was 161 m in median. In the control group there was no significant difference of performance between CE (125 ±33 W) and RE (111 ±24 W), whereas in the PAOD group, performance was lower in CE (72 ±31 W) than in RE (102 ±28 W) (P <0.01). DAP of controls increased during both CE (136 to 165 mmHg) and RE (170 to 213 mmHg), whereas the DAP of the PAOD group decreased during CE (from 85 to 44 mmHg) and remained relatively constant during RE (113 to 101 mmHg). In controls, tcPO2 did not distinctly change during TT (70 to 66 mmHg) and increased during CE (58 to 73 mmHg) and RE (69 to 82 mmHg), whereas in the PAOD group, tcPO2 decreased during TT (66 to 33 mmHg) and CE (50 to 22 mmHg) and remained almost unchanged in RE (64 to 60 mmHg). A hyperbolic relationship was found between tcPO 2 and DAP. In conclusion, during upper body exercise, blood supply to the lower extremities in patients with PAOD was not affected, whereas lower body exercise led to exhaustion of the functional reserve of blood supply. Because of a hyperbolic relationship between tcPO 2 and DAP, tcPO2 remained relatively constant if blood supply was sufficient, but in disturbed blood supply a small change of DAP was accompanied by a great change of tcPO2. Therefore, in critical ischemia the change of tcPO2 was more sensitive than that of DAP.
L-Propionylcarnitine Effect on Postexercise and Postischemic Hyperemia in Patients Affected by Peripheral Vascular Disease
Authors: Corsi Carlo , Pollastri Maurizio , Marrapodi Ernesto , Leanza Donatella , Giordano Stefania , D'Iddio Stefania 
Published: July 2008

The hemodynamic effect of L-propionylcarnitine (LPC) administered intravenously was evaluated in a double-blind, randomized, three-period crossover study in 12 men (aged sixty to seventy-five years) with Leriche-Fontaine stage II peripheral arterial disease of lower limbs. At baseline, maximum working capacity of each patient was determined by a standardized ergometric test. This test was repeated at 80% of each patient's maximum working capacity before and after intravenous administration of LPC. Each patient received three single doses of 300 mg, 600 mg, and 1200 mg of LPC with a two-day rest period between them. Hemodynamic variables measured by strain-gauge plethysmography were: peak blood flow, peak flow time, and halftime and total time of hyperemia both after exercise and after induction of ischemia (with an occlusion cuff). LPC administration significantly shortened the halftime as well as the total time of hyperemia after exercise and after ischemia. With the two highest doses, LPC shortened the peak flow time after exercise. The peak blood flow after exercise and after ischemia increased, but this increase did not reach statistical significance. The results obtained indicate that LPC improves circulatory reserve of the ischemic limb and has no effect on heart rate and arterial blood pressure. No adverse events were reported. The effect of LPC on the hyperemic response to stress, mainly on halftime of hyperemia, is possibly due to a drug-induced increase of adenosine triphosphate utiliza tion by the ischemic tissues.
A Comparative Study of Captopril and Enalapril on Endothelial Cell Function in Congestive Heart Failure Patients
Authors: Bridges A.B. , McLaren M. , Belch J.J.F. 
Published: July 2008

Angiotensin-converting enzyme (ACE) inhibitors have been shown to reduce the incidence of future coronary artery thromboses in postmyocardial infarction patients. A possible prothrombotic role for the angiotensin system has been postulated, and support for this has been provided by a recent study that demonstrated that an infusion of angiotensin increases levels of the prothrombotic plasminogen activator inhibitor (PAI). In the current study the authors have investigated the effect of two ACE inhibitors, captopril and enalapril, on tissue plasminogen activator (tPA) and PAI in 33 congestive heart failure (CHF) patients. Blood samples were obtained pretreatment and then at weeks 1, 12, and 24 after initiation of ACE inhibitor therapy for measurement of tPA antigen and PAI activity levels. The results of the study indicated that the initiation of ACE inhibitors had no signif icant effects on tPA antigen or PAI activity levels at the time points studied, and no signif icant differences were demonstrated between captopril and enalapril. The results suggest, therefore, that ACE inhibitors do not affect tPA antigen or PAI activity in CHF patients, and thus another mechanism is probably responsible for the observed decrease in coronary artery thromboses in post-MI patients treated with ACE inhibitors.
Electrocardiographic Diagnosis of the Responsible Coronary Artery in Acute Inferior Myocardial Infarction Through Right Chest Leads V3R-V8R
Authors: Prieto-Solis J.A. , Domenech J. , San Jose J.M. , Villalobos M.A. , Jimeno F. 
Published: July 2008

In order to identify the electrocardiographic changes that occur in right-chest leads V3R-V 8R for the most significant diagnosis of the responsible coronary artery of acute myocardial infarction, the authors performed a prospective study on 66 patients in whom coronary arteriography was done between the first and twelfth weeks after suffering the infarction. Electrocardiograms were done within the first six hours after the onset of symptoms. Lesions of the right coronary artery were found in 46 patients—27 at a proximal level and 19 at a distal one—and in 20 patients the circumflex coronary artery was injured. The electrocardiographic findings were studied in 2 groups of leads: V3R-V4R and V5R-V8R. An ST elevation equal to or higher than 0.5 mm and the presence of Q waves in V3R-V 4R are specific markers of lesions of the right coronary artery (P < 0.001). Lowering of the ST segment in V3R-V4R is a specific marker of a circumflex artery lesion (P < 0.001). An ST elevation equal to or higher than 1 mm in V3R-V4R is specific for a proximal lesion of the right coronary artery (P < 0.001). No specific marker for a lesion of the distal right coronary artery was identified, its more significant characteristic being an "isoelectrical" ST segment (between 0 and 0.4 mm), an rS morphology and positive T waves in V3R-V4R.
F. P. Weber Syrldrome Associated with a Brachial Artery Aneurysm
Authors: Bartels Claus , Claeys Luc , Ktenidis Kiriakos , Horsch Svante 
Published: July 2008

Klippel-Trenaunay syndrome is characterized by the triad of unilateral port-wine heman giomas, varicose veins, and hypertrophy of bone and soft tissue affecting one or more limbs. The rare F. P. Weber syndrome describes the mentioned entity and additional arteriovenous malformations. The association of an arterial aneurysm with the F. P. Weber syndrome has never been described in the current literature. A case of a brachial artery aneurysm in a patient with F. P. Weber syndrome is presented and the etiology of arterial aneurysm combined with congenital vascular abnormalities is discussed.
Transcutaneous PCO2 Level as an Index of Tissue Resistance to Ischemia
Authors: Andreozzi Giuseppe Maria , Riggio Francesco , Butto Giuseppe , Barresi Mario , Leone Alfredo , Pennisi Giuseppe , Martini Romeo , Signorelli Salvatore S. 
Published: July 2008

The authors performed a retrospective study on a data base of 525 patients with periph eral arterial disease, to analyze the pathophysiologic meaning of resting transcutaneous pressure of carbon dioxide (PCO2) and of CO2 production during three minutes of local ischemia. The resting and postischemic PCO2 and its maximum increase related to rest (PCO2 production) were measured with Kontron 7640 equipment. The results show a significant increase of PCO2 production in the Fontaine stage 2A (183 patients, 4.61 mmHg, P < 0.0001), in stage 2B (194 patients, 5.22 mmHg, P < 0.0001), in the third stage (83 patients, 6.10 mmHg, P < 0.0001), and in the fourth stage (53 patients, 8.66 mmHg, P < 0.0001). Only the patients at the first stage showed an insignificant increase, perhaps because of the small number (12) in this group. The authors feel that the measurement of tcPCO2 production during local ischemic stress can be a very important parameter for evaluating peripheral arterial disease as an expression of metabolic tissue performance and, overall, of the tissue resistance to ischemia.
Synergistic Inhibitory Effect of Angiotensin-Converting Enzyme Inhibitor and Heparin on Intimal Hyperplasia After Rat Aorta Injury
Authors: Sang Park Jang , Seung Nam Kim  , Jong Man Won  , Yong Bok Koh  , In Chul Kim  
Published: July 2008

The respective efficacies of angiotensin-converting enzyme (ACE) inhibitor and standard heparin were investigated with respect to their inhibitory effects on intimal hyperplasia after balloon denudation of rat aorta. Local angiotensin II effects in the artery wall may participate in regulation of the vascular response to arterial injury, apparently independent of the plasma renin and angiotensin system. ACE inhibitors have been shown to block intimal hyperplasia after arterial injury in rats. Increasing evidence points toward an inhibitory effect of heparin on intimal hyperplasia independent of anticoagulation. Balloon catheter aortic denudation was performed in 25 rats pharmacologically treated from six days or one day before to fourteen days after surgery and split into four groups: group A (control group), normal feeding; group B (ramipril group), ramipril 10 mg/kg/day orally; group C (heparin group), heparin 1200 IU/kg/day subcutaneously; group D (combined group), both ramipril and heparin. Animals were killed and aortas were perfused and fixed at physiologic pressure fourteen days after denudation. Cross-sectional intima-to-media area ratios (I-M ratio) were calculated by an image analyzer system. (continued on next page) Morphometric analysis of cross sections showed marked intimal thickening in the control group with a mean I-M ratio of 95.1 ±2.76%. In contrast, the I-M ratios in the ramipril group were significantly reduced by 37.3 ±2.06% (P = 0.0001) and in the heparin group by 29.7 ± 1.58%. The I-M ratio of animals treated with both ramipril and heparin was 16.6 ±1.3% (P=0.0001) (Figs. 1-7). Blood pressure in the ramipril group decreased from 111.7 ±5.16 mmHg and 91.7 ±2.58 mmHg (P = 0.0001) and in the combined group from 111.7 ± 6.06 mmHg to 92.5 ± 5.24 mmHg and 85.0 ±3.16 mmHg (P=0.0001) after seven days and fourteen days, respectively, whereas heparin had no effect on blood pressure (114.2 ±8.61 mmHg to 111.7 ±6.06 mmHg and 111.7 ±4.08 mmHg) (Fig. 8). Both the ACE inhibitor ramipril and heparin significantly reduced intimal hyperplasia. More significant reduction of intimal hyperplasia was obtained when these two drugs were given together. These data have led the authors to conclude that ACE inhibitors and heparin together inhibit intimal thickening after injury, and an apparently synergistic effect of these two drugs may be obtained. These results may be useful for clinical application to prevent the proliferation that occur after endarterectomy or bypass surgery.
Intimal Medial Thickening of Common Carotid Artery as Indicator of Coronary Artery Disease
Authors: Visonà Adriana , Pesavento Raffaele , Lusiani Luigi , Bonanome Andrea , Cernetti Carlo , Rossi Maurizio , Maiolino Pietro , Pagnan Antonio 
Published: July 2008

The authors investigated the relation between coronary atherosclerosis, angiographically detected, and intimal-medial (I-M) thickening of the common carotid artery (CCA), as measured by high-resolution B-mode ultrasound system. They studied 31 patients with coronary artery disease (CAD) and 23 healthy control subjects. I-M thickening of CCAs and atheromatous plaques at the carotid bifurcation were evaluated. A score system was defined (range 0-20) based on the absence or presence of atherosclerotic lesions at common and internal carotid arteries. A coronary angiography score was defined based on the presence of atherosclerotic lesions at nine coronary arterial segments (range 0-36) . The thickness of CCAs (M ±SD) in CAD patients was significantly higher (1.45 ±0.95 mm) than in controls (0.87 ±0.10 mm, P < 0.005), and an I-M thickening of 1.1 mm or more was specific and positively predictive of CAD. A significant positive correlation between coronary and carotid score was observed (P < 0.028, r=0.373). The study suggests that I-M thickening could be helpful for the identification of patients at risk for CAD.
Evaluation of Aortic Distensibility in Patients with Coronary Artery Disease by Use of Cine Magnetic Resonance
Authors: Matsumoto Yuji , Honda Toshio , Hamada Mareomi , Matsuoka Hiroshi , Hiwada Kunio 
Published: July 2008

To evaluate the aortic wall sclerosis in patients with coronary artery disease (CAD), the authors measured the aortic distensibility (AD) at the ascending and descending aorta by using cine magnetic resonance (MR). Cine MR was performed in 15 patients with CAD and 15 normal controls (NCs). Patients with CAD had angiographically significant coronary arterial stenosis and almost normal left ventricular function. Age and sex were matched in the patients with CAD and the NCs. Ascending and descending aortic areas of transverse image were measured in the maximum and minimum frames. AD was calculated from the following formula: (max area - min area) / (min area x pulse pressure). Although systolic and diastolic blood pressures showed no significant differences between patients with CAD and NC, AD was significantly lower in patients with CAD than in the NCs in each transverse section (P < 0.05). In conclusion, it is indicated that aortic wall sclerosis is advanced in patients with CAD.
Secondary Prevention of Coronary Heart Disease in Patients with Extracoronary Atherosclerosis: A Need for Accuracy of Low Density Lipoprotein Determination
Authors: Senti Mariano , Pedro-Botet Juan , Rubiés-Prat Juan , Vidal-Barraquer Francesc 
Published: July 2008

According to the new guidelines of the National Cholesterol Education Program (NCEP) for secondary prevention in adults with evidence of coronary heart disease or other clinical atherosclerotic disease, lipoprotein analysis is required and classification is based on low density lipoprotein (LDL) cholesterol. The aim of the present study was to analyze the reliability of calculated LDL cholesterol by the Friedewald formula compared with measured LDL cholesterol after separation by ultracentrifugation in 202 male patients with extracoronary atherosclerosis (100 patients with ischemic cerebrovascular disease and 102 patients with peripheral vascular disease) and in 117 healthy control subjects. Calculated LDL cholesterol coincided with measured LDL cholesterol, with less than 10% error, in 118 patients (58.4%) with extracoronary atherosclerosis and in 87 controls (74.4%). Calculated LDL cholesterol was overestimated, with an error of 10% or more compared with measured LDL cholesterol, in 34.6% of patients and 22.2% of controls, and underestimated in 6.9% and 3.4%, respectively. Despite a good correlation between calculated and measured LDL cholesterol, the intraclass correlation coefficients demonstrate a poor concordance between calculated and measured LDL cholesterol, both in patients and controls. The authors underline the need for caution in assessing the reliability of calculated LDL cholesterol.
TcPO 2 Measurement Reproducibility During Stress in Stage II Obliterative Arterial Disease
Authors: Mouren X. , Caillard Ph. , Massonneau M. , Thébault B. 
Published: July 2008

Distal transcutaneous oxygen pressure measurement (TcPO2) is a noninvasive method of evaluating tissular hypoxemia in peripheral arterial disease. The poststress area of hypoxemia is a useful technique for globally quantifying different parameters represented by TcPO2 curves during exercise. Although its use is increasingly widespread, the reproducibility of this method is poorly documented. TcPO2 was monitored three times at twenty-four hour intervals in 5 patients with stage II obliterative arterial disease during a treadmill walking test. In order to get uniform measurement conditions, each patient remained lying and then stood until TcPO 2 became stable. The stress duration was calculated so that the pain step could not be reached. TcPO2 curves were digitized and a specific image analyzer was used to make replicate measurements. The area under the curve was computed, the horizontal axis determining the mean TcPO2 value at rest, the vertical axis representing the end of the exercise period. The corresponding areas under the curves ranged from 34 to 2212 mm2 (573.60; SD 826). Significant correlation coefficients were obtained among replicate measurements (first-second day, first-third day). However, owing to the wide range of area values, the authors decided to compute and use the coefficient of variation (STD/mean), since it was more representative of reproducibility. The mean of its value for 5 patients was 21%. Observation of the examination conditions resulted in several findings, especially the ability of certain patients to adapt their efforts to the exercise. These results indicate that TcPO2 poststress area measurements are reproducible, but the conditions of the exercise have to be rigorously defined and may still be improved.
Acute Exposure to Carbon Monoxide Does Not Affect Plasma Lipids, Lipoproteins, and Apolipoproteins
Authors: Leaf David Alexander , Kleinman Michael T. 
Published: July 2008

Study objectives: To examine the effects of acute exposure to carbon monoxide and hypoxia on plasma lipids, lipoproteins, and apolipoproteins. Design: Random-order assignment to blinded, inhaled exposures of carbon monoxide and hypoxia. Setting: Research laboratory of ambulatory subjects. Subjects: 10 elderly, male nonsmokers with chronic stable angina. Intervention: Random-order two-hour inhaled exposure to clean air at sea level, carbon monoxide at sea level, carbon monoxide at high altitude, and clean air at high altitude. Measurements: Fasting plasma lipids, lipoproteins, and apolipoproteins before and after exposures. Results: No differences were noted between fasting plasma lipid, lipoprotein, or apolipoprotein levels before and after exposures. Conclusion: Acute exposure to carbon monoxide and high altitude does not affect fasting plasma lipid, lipoprotein, or apolipoprotein levels.