bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antihypertensive Therapy with Isradipine in Patients with Special Safety Concerns
Authors: Blecker David 
Published: July 2008

Treatment of hypertension in the complicated patient requires a specialized approach focusing on the treatment of the blood pressure and concurrent medical problems. Therapy must be chosen in consideration of the patient's age, multiple illnesses, declining organ function, and possible drug interactions. This requires that the antihypertensive agent chosen have a demonstrated safe profile. In clinical trials, monotherapy with the calcium channel blocker (CCB) isradipine (ISR) at a recommended therapeutic dosage has controlled blood pressure with an excellent level of safety. In these studies, ISR had no significant effect on heart rate, cardiac conduction, or cardiac contractility and no negative effect on renal function. In hypertensive patients with both normal and impaired renal function, ISR significantly increased renal plasma flow while decreasing renal vascular resistance without decreasing glomerular filtration rate and filtration fraction. ISR has long-term natriuretic effects that may provide additional benefits in antihypertensive therapy. Most adverse effects associated with ISR are mild, transient, and related to vasodilation. The most frequently reported adverse reactions are headache, dizziness, and edema. ISR does not affect glycemic control or lipid metabolism in either diabetic or nondiabetic patients. It has no reported adverse interaction with some of the most commonly used medications for elderly patients, including digoxin, nitroglycerin, oral hypoglycemics, and hydrochlorothiazide. ISR may be used as a first-line agent for the treatment of hyper tension in complicated patients.
Plasma Levels of Tumor Necrosis Factor and Endothelial Response in Patients with Chronic Arterial Obstructive Disease or Raynaud's Phenomenon
Authors: Cimminiello Claudio , Arpaia Guido , Toschi Vincenzo , Rossi Florica , Aloisio Manuela , Motta Adele , Bonfardeci Giuseppe 
Published: July 2008

Tumor necrosis factor alpha (TNF-alpha) is a cytokine that affects endothelial cells' function by changing their antithrombotic potential to a net procoagulant effect. Only a few data have so far been reported for the pathophysiologic role of TNF in vascular diseases in the involvement of microvessels and/or macrovessels and a prothrombotic state. In the present study the authors evaluated plasma TNF (and interleukin-1) levels in 20 patients with chronic arterial obstructive disease (CAOD) with intermittent claudi cation and 10 CAOD patients with more severe disease (pain at rest/skin ulcers). In addition, they studied 10 patients with Raynaud's phenomenon (RP), suspected to be secondary to a collagen disease. The control group consisted of 20 subjects matched for sex and age with the three groups of patients. TNF levels were assayed by enzyme-linked immunosorbent assay The antigen levels of von Willebrand factor (vWF), tissue plasminogen activator (t- PA), and its inhibitor (PAI) were also determined as markers of release from the endothe lium, while the fragment 1+2 of prothrombin (F1+2) and thrombin-antithrombin III (TAT) complexes were assessed as indexes of systemic thrombin generation. TNF levels were significantly higher in both groups of CAOD patients than in controls or RP patients, and the same was true for vWF. t-PA was significantly higher only in the CAOD subjects with more severe disease. No differences among groups were seen in PAI antigen/activity or thrombin generation. When data were corrected for age, TNF no longer differentiated CAOD patients from controls and RP subjects. There were strong direct correlations between TNF and age ( r=0.57, P=0.0001); TNF and t-PA (r=0.43, P=0.002); and TNF and vWF (r=0.52, P=0.0001). The association of TNF with vWF was indepen dent of other variables. The present study suggests that TNF plays an important role in the pathophysiology of arterial diseases of atherosclerotic origin, especially during aging.
Left Ventricular Remodeling and Function in Adult Aortic Stenosis
Authors: Faggiano Pompilio , Rusconi Cesare , Ghizzoni Giuseppe , Sabatini Tony 
Published: July 2008

The aim of this study was to analyze the left ventricular (LV) geometric changes occurring in chronic pressure overload due to valvular aortic stenosis (AS). Fifty-six adult patients (30 women, 26 men, mean age seventy-two ±nine years, range forty-five to eighty-five years) with isolated AS (mean valve area by Doppler=0.6 ±0.2 cm2) underwent a complete Doppler echocardiographic examination. According to the value of relative wall thickness (RWT=2 x posterior wall thickness/LV end-diastolic diameter) and LV mass index (LVMI) in normal subjects (RWT ≤ 0.44, LUMI ≤ 125 gr/m2) AS patients were subdivided into four groups: Normal: no patients; Concentric Remodeling (RWT > 0.44, LVMI ≤ 125 gr/m2): 4 patients (7%); Concentric Hypertrophy (RWT > 0.44, LVMI > 125 gr/m2): 39 patients (70%); and Eccentric Hypertrophy (RWT ≤ 0.44, LVMI > 125 gr/m2): 13 patients [23%]. Eccentric hypertrophy patients had, as compared with those with concentric hypertrophy, a larger left ventricle (61 ± 6.5 mm vs 47.6 ±6 mm, P < 0.001), a smaller mean wall thickness (11.3 ± 1.2 vs 14.7 ± 1.7 mm, P ≤ 0.001), and reduced LV fractional shortening (FS%=22.9 ±11 vs 42.6 ±8.7%, P < 0.001). Furthermore, most patients (11/13) of the former group had heart failure due to LV systolic dysfunction, while only 16 of 39 patients of the latter group had heart failure and all but 2 had normal LV systolic function. Conclusion: In patients with aortic stenosis, different forms of LV remodeling occur in response to chronic pressure overload. According to these results (and recent experi mental data), eccentric hypertrophy likely represents a late and more severe stage of LV remodeling in aortic stenosis.
Digital Blood Flow Response to Body Warming, Cooling, and Rewarming in Patients with Raynaud's Phenomenon
Authors: Lau C.S. , Khan F. , Brown R. , Belch J.J.F. 
Published: July 2008

Although the diagnosis of Raynaud's phenomenon (RP) is usually made easily from a careful history, the assessment of RP severity is difficult, for the vasopastic attacks are not easily induced under experimental conditions. In this study, the laser Doppler flowmetry (LDF) technique was used to quantify digital blood flow, which was standardized by body cooling and warming in patients with RP. Twenty-one healthy subjects and 56 RP patients were studied: 7 had primary RP, 22 had suspected secondary Raynaud's syndrome (susp RS), and 27 had systemic sclerosis (SSc)-associated secondary Raynaud's syndrome (SSc RS). The inherent variability in the acral cutaneous circulation was minimized by whole-body warming and cooling. Digital blood flow values at environmental temperatures of 40°C, 12°C, and after rewarming, to 40°C were recorded, as was the time taken for blood flow to reach 25%, 50%, and 75% of the full effects of whole-body cooling and rewarming. Patients with primary RP and susp RS had normal blood flow values at ambient temperatures of 40°C, 12°C, and after rewarming to 40°C when compared with controls, but they had significantly faster vasoconstrictor responses to whole-body cooling, suggesting a heightened sympathetic activity. Additionally, they had slower vasodilator responses with longer 25%max response time to whole-body rewarming. Patients with SSc RS had significantly lower blood flow values at 40°C after initial warming and following subsequent rewarming, and despite a normal vasoconstrictor response to cooling, it took longer for them to vasodilate during rewarming, suggesting that poor digital blood flow in these patients may be more related to digital vasculature abnormalities and not an increase in sympathetic activity. In conclusion, our assessment technique can be used to quantify digital blood flow in patients with RP and may be potentially useful in the investigation of the etiologic role of the sympathetic nervous system in RP.
Comparative Diagnostic Value of Ankle-to-Brachial Index and Transcutaneous Oxygen Tension at Rest and After Exercise in Patients with Intermittent Claudication
Authors: de Groote Pascal , Millaire Alain , Deklunder Guislaine , Marache Philippe , Decoulx Eric , Ducloux Gerard 
Published: July 2008

Background: Few studies have compared sensitivities of ankle-to-brachial index (ABI) and transcutaneous oxygen tension (TcPO2) in a large group of patients with Leriche stage II intermittent claudication. Method and Results: 111 patients (138 limbs) with a stable chronic (> three months) intermittent claudication and significant peripheral vascular disease (PVD) proved by angiography were studied. They performed a treadmill test (10%, 3 km/hr) limited by limb pain. ABI and TcPO2 were measured before, just after exercise, and after three and ten minutes of recovery in supine position. Sensitivities per patient for ABI and TcPO2 were respectively at rest: 82.9% and 28.8%, and after exercise: 88.3% and 62.2%. Sensitivities per leg (n=138) for ABI and TcPO2 were respectively at rest: 73.9% and 26.8%, and after exercise: 82.6% and 34%. The sensitivity of TcPO2 increased to 56.5% after three minutes of recovery but was always less than that of ABI, which was maximal just after exercise (82.6%). The sensi tivity of the regional perfusion index was similar to that of TcPO2. The sensitivity of TcPO2 increased with respect to the Leriche stage and the number of lesions but was always lower than that of ABI. There was a weak correlation between TcPO2 and ABI after exercise, but no correlation was noted between maximal walking distance, ABI, and TcPO2. Conclusion: TcPO 2 is not required in patients with Leriche stage II intermittent clau dication but might be useful either in severely affected patients (Leriche stage III or IV) or in selected patients.
A New Echocardiographic Formula to Calculate Ejection Fraction by Using Systolic Excursion of Mitral Annulus
Authors: Çevik Y. , Degertekin M. , Başaran Y. , Turan F. , Pektaş O. 
Published: July 2008

The correlation between echocardiographically and angiographically calculated ejection fraction and systolic excursion of the mitral annulus was studied in 81 patients. Knowing that the mitral annulus changes its size, shape, and position during the cardiac cycle, the authors measured systolic excursion of the annulus by 2D echocardiography. Displacement of the mitral annulus was measured from four different points (medial, lateral, anterior, posterior) by apical four-chamber and apical two-chamber approaches. Patients with and without regional wall motion abnormalities were included. Left ventric ular volumes and ejection fraction (EF) were calculated in the standard manner intro duced by Teichholz et al and also with biplane left ventriculography. As a result, EF calculated by cineangiography, was moderately correlated with the Teichholz method (r=0.66) while it was highly correlated with measurements of mitral annular motion (MAM) (r=0.87). The correlation can be expressed by the regression equation, EF (angiography) =5.7 MAM (in mm) - 6.5. They conclude that measurements of annular motion is an easy and reliable index of left ventricular function as an alter native to traditional methods.
Skin Oxygen Pressure Histograms in Patients with Peripheral Arterial Occlusive Disease During Intraarterial and Intravenous Prostaglandin E1 Infusions of Different Dosages and Their Prognostic Value
Authors: Creutzig Andreas , Arnold Andreas , Caspary Ludwig , Thum Joachim , Alexander Klaus 
Published: July 2008

Skin surface oxygen pressure fields (tcPO2 [37°C]) reproducibly characterize skin microcirculation in patients with peripheral arterial occlusive disease. These appear suited for investigation of short- and long-term effects of vasoactive drug treatment. The authors studied whether skin surface oxygen pressure histograms change depending on dosage and route of administration of prostaglandin E1 (PGE1), whether they are of predictive value for patients' clinical outcome, and whether they normalize after therapy with PGE1 . The authors investigated 15 patients with various degrees of disease and measured forefoot oxygen histograms consisting of at least 80 single tcPO2 (37°C) values before and during intraarterial infusion (1.5, 3, or 6 ng/kg/minute) and intravenous infusion (4.5, or 9 ng/kg/minute). The measurements were repeated two and six hours after the end of intraarterial application of 1.5 ng/kg/minute. Furthermore, the orthostatic vasoconstrictor response was tested. Skin oxygen pressure histograms were controlled after a period of twenty-two (mean) days of intraarterial PGE1 therapy. Resting histograms were left shifted with median tcPO2 (37 ° C) between 1 and 7 mm Hg. During intraarterial application, histograms were shifted to lower tcPO 2 (37 ° C) values in most patients. Only in 3 diabetic subjects with proximal or acral obliterations was a marked increase observed. The alterations were detectable at least two hours after the end of the infusion. During intravenous infusion, histograms did not change in most cases. After long-term therapy, histograms were substantially unchanged. A pathologic vasoconstrictor response, which was present in 10 patients, could not be restored. Despite a marked deterioration of the histograms the clinical outcome was favorable in 7 patients. Patients with a high resting tcPO2 (37 ° C) (median 4 mm Hg and more) and those with a vasoconstriction on orthostasis are likely to respond to PGE1 therapy.
Predicting the Growth of Aortic Aneurysms: A Comparison of Linear vs Exponential Models
Authors: Hirose Yoshiaki , Hamada Seiki , Takamiya Makoto 
Published: July 2008

The aim of the present study was to determine whether the growth curve of aortic aneurysms had a predictable pattern, specifically whether the growth pattern was better defined by a linear or exponential rate of growth. A twelve-year retrospective review was undertaken. The authors studied 59 patients with aortic aneurysm who have been followed up nonoperatively for more than three years with sequential computed tomographic (CT) scans. There was a total of 74 aortic aneurysms (thoracic aortic aneurysm [TAA] : 30, abdominal aortic aneurysm [AAA]: 44). The diameter of the aortic aneurysm was normalized by dividing by the initial diameter. Exponential ( y= A exp [ Bt]) and linear ( y= C + Dt) regression curves of growth of aneurysmal diameters were calculated, where y is the normalized diameter and t is the time after first CT examination in months. In regression analysis, the values fit well to the exponential growth curves, giving high regression coefficients. Exponential regression equations of TAA and AAA were y=1.0192 exp(0.0032t), r=0.720 andy=1.0129 exp(0.0045t), r=0.789, respectively. The results in favor of the exponential curve analysis were slightly higher than those favoring the linear curve. This is the first study that showed the growth curves of aortic aneurysms. Aortic aneurysms may grow exponentially rather than linearly with time, and the growth curves might be useful for estimating the natural history or predicting the timing of surgery.
Effect of the Number of Ventricular Leads on Right Ventricular Hemodynamics in Patients with Permanent Pacemaker
Authors: Postaci Nursen , Ekşi Kenan , Bayata Serdar , Yeşil Murat 
Published: July 2008

During pacemaker replacement most of the old leads are not suitable for recent needs or may show signs of dysfunction. These leads are difficult to extract and are therefore left-in situ. In this study 32 patients with one ventricular lead (Group I) were compared echocardiographically with 18 patients with two ventricular leads (Group II) in regard to their right ventricular (RV) hemodynamics. Mean age of the patients in each group was sixty-one years. Patients were evaluated echocardiographically after two years of lead implantation. Two groups were compared for right atrial (RA) area, RA and RV diameters, tricuspid insufficiency (TI), and intravascular and intracardiac thrombosis. There were no significant differences between the two groups in terms of RA and RV diameters, RA area, and venous and intracardiac thrombosis. In group I, 15 patients with (46.9%) grade I, 14 (43.7%) with grade II, and 3 (9.4%) with grade III TI were detected. In group II 2 patients (11.1%) with grade I, 6 (33.3%) with grade II, and 10 (55.6%) with grade III TI were detected. In conclusion, the incidence of TI was more frequent and of higher degree in group II than in group I, but this finding was hemodynamically insignificant.
In Vivo Measurement of Regional Large Artery Compliance by Intravascular Ultrasound Under Pentobarbital Anesthesia
Authors: Wilson Richard A. , Di Mario Carlo , Krams Rob , Loe Kie Soei  , Wenguang Li , Laird Anne C. , The Salem H. K. , Gussenhoven Elma , Verdouw Pieter , Roelandt Jos R. T. C. 
Published: July 2008

Background: The presence of smooth muscle fibers on the wall of large arteries would suggest that arterial compliance might change in response to vasoactive substances. The purpose of this study is to determine the basal level of vasomotor tone in these arteries in a commonly used animal preparation and to learn whether the compliance of large conductance arteries can be altered in vivo by vasoactive agents. Methods: Proximal iliac arterial compliance was measured in 7 pentobarbital-anes thetized pigs, before and during local infusions of adenosine and norepinephrine. Luminal area was measured every forty milliseconds by means of a 30 MHz intravas cular ultrasound catheter and an automatic edge detection program. Simultaneous high- fidelity pressure measurements were obtained by means of a catheter-tipped pressure microtransducer positioned at the origin of the iliac artery. Linear regression analysis of the area/pressure relationship in two consecutive cardiac cycles (systolic phase only) was performed before and during adenosine and norepinephrine infusions. The slope of the area/pressure regression line was defined as an index of arterial compliance. Measurements after three minutes of infusions of adenosine (5-5000 μg/minute) and norepinephrine (0.001-10 μg/minute) were compared with the control measurements. Results: Even at the highest infusion rate, adenosine did not significantly increase arterial compliance as compared with baseline (25 ± 7 vs 19 ±4 mm2/mmHg x 10-3, respectively, P = ns). In contrast, norepinephrine decreased arterial compliance as compared with the second baseline control (13 ±3 vs 20 ±3 mm2/mmHg x 10-3, respectively, P < 0.01). Conclusions: In this animal model with pentobarbital anesthesia, arterial compliance may be modified more by the acute infusion of norepinephrine than by adenosine in large conductance arteries such as the proximal iliac. Thus, in this preparation, smooth muscle tone tends to be minimal and arterial compliance near maximal (ie, mostly a passive phenomenon). However, in response to norepinephrine, arterial compliance can decrease significantly as smooth muscle tone increases. Intravascular ultrasound allows continuous and accurate monitoring of these changes of arterial dimensions, suggesting that this technique may be useful in the evaluation of pharmacologically induced changes in the compliance of large arteries by vasoactive agents.
Relation Between Postpacing T Wave Changes and Myocardial Scintigraphic Characteristics in Patients with Ventricular Demand Pacemaker
Authors: Abe Mitsunori , Hamada Mareomi , Matsuoka Hiroshi , Shigematsu Yuji , Sumimoto Takumi , Okayama Hideki , Kawakami Hideo , Nakata Shigeru , Hiwada Kunio 
Published: July 2008

The aim of this study was to elucidate the cause of T wave changes after ventricular pacing using thallium 201 single photon emission computed tomography (T1-SPECT). T1-SPECT was performed in 20 patients with sick sinus syndrome who had negative T wave after ventricular pacing and had had a ventricular demand pacemaker (WI) implanted. Patients who have stenotic coronary arteries were excluded from the study. From the analysis of Tl-SPECT, extent score was calculated as the ischemic region. Data in patients with SSS were compared with those in 20 normal controls (NC). Thallium perfusion defects in patients with VVI were observed and distributed mainly in apex and inferior regions on the polar map. The extent score in patients with VVI was significantly higher than that in NC (56.4 ±21.6% vs 3.2 ±6.4%, P < 0.01). The washout rate of thallium 201 in the defect area was significantly lower in patients with VVI than in NC (27.4 ±10.2% vs 46.8 ±12.3%, P<0.01). These results suggest that T wave changes after ventricular pacing are closely related to myocardial ischemia.
Comparing a High-Dose Dipyridamole SPECT Imaging Protocol with Dobutamine and Exercise Stress Testing Protocols
Authors: Fleming Richard M. , Rose Charles H. , Feldmann Kristine M. 
Published: July 2008

Objective. To determine the safety, sensitivity, specificity, and accuracy of high-dose dipyridamole compared with treadmill and dobutamine stress imaging protocols. Background. Nuclear imaging studies using standard dose dipyridamole provide similar results to those obtained when treadmill stress is used. Recently dobutamine tomography and planar imaging with high-dose dipyridamole have been shown to improve nuclear imaging results. Methods. One hundred fifty-nine patients were imaged with thallium, teboroxime, or sestamibi per standard single photon emission computed tomography (SPECT) protocols. Pharmacologic stress was performed in 85 people with the remainder under going exercise testing by Bruce protocol. In this study, 0.852 mg dipyridamole was used per kilogram body weight and was infused over a four-minute period. Results from nuclear imaging were compared with those from coronary arteriograms. Results. The sensitivity and specificity of high-dose dipyridamole was 100% and 88.9%, respectively, which is statistically greater (P < 0.005) than that achieved when patients were stressed by treadmill. Side effects with the higher dose of dipyridamole were easily reversed with aminophylline. The sensitivity and specificity of intravenous dobutamine was 100%, but it was used in a limited number of subjects. When patients were stressed by Bruce protocol the sensitivity was 92.5% and specificity was 42.8%. The differences were not attributable to inadequate exercise duration. Conclusions. High-dose dipyridamole is safe and easily reversed with intravenous aminophylline. The sensitivity and specificity of dipyridamole and dobutamine stress testing were statistically more accurate than results obtained with treadmill protocols when SPECT is used to image the heart. High-dose dipyridamole resulted in greater changes in heart rate and blood pressure response than seen with standard-dose dipyridamole. Associated side effects can be easily reversed with the administration of intravenous aminophylline without significant complications. The sensitivity, specificity, and accuracy of single photon emission computed tomography using high-dose dipyridamole are 100%, 88.9%, and 97.9%, respectively, for the overall presence or absence of disease when compared with coronary arteriography. This is significantly (P < 0.005) greater than that obtained by treadmill nuclear imaging protocols, independent of imaging agent.