bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of aging on atrial endocardial electrograms in patients with paroxysmal atrial fibrillation
Authors: Camm A. John , Centurión Osmar Antonio , Isomoto Shojiro , Shimizu Akihiko , Konoe Atsushi , Kaibara Muneshige , Hirata Tetsuya , Hano Osamu , Sakamoto Ryoji , Hayano Motonobu , Yano Katsusuke 
Published: June 2007

AbstractBackground: The prevalence of atrial fibrillation (AF) has been reported to increase with advancing age. Histologic studies in AF have demonstrated that the percentage of fibrosis and degenerative changes in the atrial muscle increase significantly with age.Hypothesis: This study was undertaken to assess the influence of advancing age on atrial endocardial electrograms recorded during sinus rhythm in patients with paroxysmal atrial fibrillation (PAF), which had not been assessed previously.Methods: Right atrial endocardial catheter mapping during sinus rhythm was performed in 111 patients with PAF to evaluate the influence of advancing age onatrial endocardial electrograms. The bipolar electrograms were recorded at 12 sites in the right atrium, and an abnormal atrial electrogram was defined as lasting ≥ 100 ms, and/or showing eight or more fragmented deflections.Results: In all, 1,332 right atrial endocardial electrograms were assessed and measured quantitatively. The number of abnormal atrial electrograms in patients with PAF showed a significantly positive correlation with age (r = 0.34; p<0.0005). Patients aged > 60 years had a significantly greater mean number of abnormal electrograms (2.58 ± 2.05) than those aged < 60 years (1.43 ± 2.03; p<0.004). The longest duration (r = 0.35; p<0.0005) and the maximal number of fragmented deflections (r = 0.29; p<0.005) of atrial electrograms among the 12 right atrial sites also showed a significantly positive correlation with age.Conclusions: Aging alters the electrophysiologic properties of the atrial muscle in patients with PAF. Elderly patients have a significantly greater abnormality of atrial endocardial electrograms than do younger ones. There is a progressive increment in the extension of altered atrial muscle with advancing age in patients with PAF.
Asymmetrical dimethylarginine: A novel risk factor for coronary artery disease
Authors: Lu Tse‐Min , Ding Yu‐An , Charng Min‐Ji , Lin Shing‐Jong 
Published: June 2007

AbstractBackground: Asymmetrical dimethylarginine (ADMA) is an endogenous competitive inhibitor of nitric oxide synthase and has been associated with systemic atherosclerosis; however, the role of ADMA in patients with coronary artery disease (CAD) has not been investigated.Hypothesis: The present study was designed to determine whether the plasma ADMA level predicts the presence of CAD independently, and whether the plasma ADMA level correlates with the extent and severity of coronary atherosclerosis.Methods: In all, 97 consecutive patients with angina and positive exercise stress test were enrolled prospectively for coronary angiography. According to the result of angiography, the subjects were divided into two groups: Group 1 (n = 46): patients with normal coronary artery or mild CAD (< 50% stenosis of major coronary arteries); group 2 (n = 51): patients with significant cad (≥ 50% stenosis of major coronary arteries). plasma levels of adma and l‐arginine were determined by high‐performance liquid chromatography. in addition, we used coronary atherosclerotic score to assess the extent and severity of cad.Results: The plasma levels of ADMA in Group 2 patients were significantly higher than those in Group 1 patients (0.66 ± 0.17 μM vs. 0.44 ± 0.09 μM, p < 0.001); these were accompanied by significantly lower plasma l‐arginine/adma ratio in patients with significant cad (group 1 vs. 2: 194.0 ± 55.3 vs. 136.7 ± 50.3, p < 0.001). in a multivariate stepwise logistic regression analysis, both plasma adma level and plasma l‐arginine/adma ratio were identified as independent predictors for cad. moreover, there were significant positive and negative correlations between coronary atherosclerotic score and plasma adma level as well as plasma l‐arginine/adma ratio, respectively (plasma adma level: r = 0.518, p < 0.001; l‐arginine/adma ratio: r = 2 0.430, p < 0.001).Conclusions: Both plasma ADMA level and plasma L‐arginine/ADMA ratio were useful in predicting the presence of significant CAD and correlated significantly with the extent and severity of coronary atherosclerosis. Our findings suggest that plasma ADMA level may be a novel marker of CAD.
Rapid effects of simvastatin on lipid profile and C‐reactive protein in patients with hypercholesterolemia
Authors: Li Jian‐Jun , Chen Ming‐Zhe , Chen Xin , Fang Chun‐Hong 
Published: June 2007

AbstractBackground: Rapid lowering of low‐density lipoprotein (LDL) cholesterol levels as well as C‐reactive protein (CRP) by administration of drugs may produce early benefit to the coronary endothelium in patients with coronary heart disease and reduce angina and coronary events after revascularization. Limited information has been available in evaluating a potentially effective first 2‐week therapeutic approach for the treatment of patients with hypercholesterolemia using a statin.Hypothesis: The study was undertaken to investigate whether a rapid LDL cholesterol and CRP reduction can be achieved by 2‐week simvastatin therapy using a common lipid‐lowering protocol in patients with hypercholesterolemia.Methods: Forty‐two patients were randomly assigned to 20 or 40 mg/day of simvastatin. Blood samples were drawn at Day 0 and at Day 14 for measuring lipid profile, CRP levels, and hepatic enzymes in all patients.Results: The results showed that both doses of simvastatin (20 and 40 mg) induced significant reductions in total cholesterol (TC, 25 and 38%) and LDL cholesterol (31 and 46%) compared with baseline. However, the highest dose of simvastatin (40 mg) resulted in significantly greater reductions in TC and LDL cholesterol (p = 0.04, p = 0.02, respectively) compared with the group receiving 20 mg (p < 0.04, p < 0.02, respectively). a less significant reduction was observed in mean triglycerides (tg) level (16 and 25%) compared with tc and ldl cholesterol. there was no significant difference in mean high‐density lipoprotein (hdl) cholesterol levels compared with baseline in either group. in addition, both doses of simvastatin induced significant reductions in mean crp levels on day 14 (22.3 and 23.1%) in a non dose‐dependent manner (p < 0.001, respectively).Conclusions: Our data suggest that a common daily dose of simvastatin, especially 40 mg, is an effective 2‐week therapy for patients with hypercholesterolemia, and benefit to the vascular endothelium can be derived quickly by reduction of CRP levels.
Relation of ultrasonic tissue characterization with integrated backscatter to contractile reserve in patients with chronic coronary artery disease
Authors: Hu Xiaojun , Wang Jinming , Sun Yougang , Jiang Xia , Sun Bin , Fu Haixia , Guo Ruiqiang 
Published: June 2007

AbstractBackground: Previous studies have shown that viable but stunned myocardium displays contractile reserve and exhibits cardiac cycle‐dependent variations of integrated backscatter (CVIB), whereas infarcted myocardium does not.Hypothesis: This study was designed to clarify whether assessment of the acoustic properties of the myocardium can predict contractile reserve in patients with chronic coronary artery disease (CAD).Methods: In all, 21 patients with chronic CAD and 19 normal control subjects were studied. The magnitude of CVIB of the myocardium was measured in the basal and mid segment of the anterior septum and posterior wall of the left ventricle, using a real‐time, two‐dimensional integrated backscatter imaging system. The results were compared with the percent systolic wall thickening and the wall motion before and after revascularization. The wall motion was graded as normal, hypokinetic, or akinetic, and contractile reserve was considered present when an akinetic or hypokinetic segment improved after revascularization.Results: The average magnitude of CVIB was lower among dysfunctional segments of CAD than among normal segments of controls (3.73 ± 1.71 vs. 6.35 ± 0.69, p < 0.001). of the 77 segments examined, 38 showed reversible dysfunction. before revascularization, percent systolic wall thickening was similar among segments showing contractile reserve compared with those with persistent dysfunction myocardium (17.97 ± 8.41 vs. 16.83 ± 6.37%, p = 0.19), and the mean cvib was significantly greater in segments with than in those without contractile reserve (4.73 ± 1.47 vs. 2.75 ± 1.31, p < 0.001). the cvib above 3 db before percutaneous transluminal coronary angioplasty predicted segments with contractile reserve with a sensitivity and specificity of 84.2 and 79.5%, respectively.Conclusions: Cardiac cycle‐dependent variations of integrated backscatter reflected myocardial contractility and functional capacity of the myocardium. They predicted segmental contractile reserve in patients with CAD.
New insights into the mechanisms of temporal variation in the incidence of acute coronary syndromes
Authors: Strike Philip C. , Steptoe Andrew 
Published: June 2007

AbstractOver the last few years, patterns have emerged re‐gardingthe daily (circadian), weekly (circaseptan), and yearly (circannual) variation in the incidence of acute coronary syndromes (ACS). Peaks of incidence occur in the morning, on Mondays, and in winter. There is a difference in the pattern of incidence in different subgroups such as diabetics and smokers, which, along with the incidence alteration seen with aspirin and beta blockers, gives us some potential understanding of underlying mechanisms. Recent advances in the study of endothelial function, cytokine biology, and adhesion molecules have led to new insights into the way that natural fluctuations in these systems may affect ACS incidence. It is hoped that understanding these developments will lead to therapeutic advances in ACS prevention.
Angiotensin II blockade: A therapeutic strategy with wide applications
Authors: Aranda Juan M. , Conti C. Richard 
Published: June 2007

AbstractEvidence now exists suggesting a pathologic role for angiotensin II in patients with cardiovascular disease and those with risk factors. Clinical trials such as the Losartan Intervention for Endpoint Reduction in Hypertension Study (LIFE), the Heart Outcomes Prevention Evaluation Study (HOPE), the African American Study of Kidney Disease and Hypertension (AASK), and the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study have clearly demonstrated that blood pressure reduction is important in hypertension and diabetes. If this can be accomplished with agents that block the renin‐angiotensin system, then additional clinical benefit will be achieved. Clinical data on angiotensin‐converting enzyme inhibitors (ACEIs) are well established, while emerging data on the use of angiotensin II receptor blockers (ARBs) continue to grow. There is evidence supporting the concept of angiotensin II escape in the presence of ACEIs. The question that remains to be answered is whether a combination of both agents (ACEIs and ARBs) can improve clinical outcomes. Ongoing clinical trials will answer this question.
Changes in the response of hibernated myocardium to inotropic stimulation after angioplasty: A doppler myocardial imaging study
Authors: Klisiewicz Anna , Michałek Piotr , Szymański Piotr , Hoffman Piotr 
Published: June 2007

AbstractBackground: Angioplasty of an infarct related artery (IRA) performed several weeks or months after myocardial infarction (MI) may improve myocardial function.Hypothesis: We hypothesized that, as Doppler myocardial imaging (DMI) allows forthe quantitative assessment of the systolic movement of myocardial segments, it may be a sensitive method for assessing changes in regional myocardial contraction and contractile reserve pre and post angioplasty of the IRA.Methods: In all, 39 patients (30 men, mean age 53.4 ± 8.3 years), 1 to 6 months after MI, who qualified for IRA angioplasty on the basis of myocardial viability in the infarcted zone as demonstrated by dobutamine stress echocardiography, were included in the study. Peak regional myocardial systolic velocities (S wave) of the infarcted segments were measured at rest and during low‐dose dobutamine infusion (15 μg/kg/min) 1 day before angioplasty (Exam 1), 2 to 5 days (Exam 2), and 30 days (Exam 3) after successful angioplasty. The long‐axis movement of the mitral annulus and of the basal and medial segments of the posterior (20 patients), anterior (17 patients), and lateral walls (2 patients) was evaluated.Results: At rest, S‐wave velocity of the infarcted segments increased between Exams 1 and 2, without further improvement between Exams 2 and 3 (4.9 ± 1.2 vs. 5.6 ±1.3 cm/s, p<0.05 and 5.6 ± 1.3 vs. 5.5 ± 1.3 cm/s, NS, respectively). However, S‐wave velocities measured during low‐dose dobutamine infusion differed significantly both between Exams 1 and 2, and 2 and 3 (7.0 ± 1.5 vs. 7.8 ± 1.8 cm/s; p<0.01; 7.8 ± 1.8 vs. 8.5 ± 1.6 cm/s; p<0.05).Conclusions: Resting contractility at an infarct zone demonstrated rapid initial improvement after angioplasty of the IRA with no further change, whereas contractile reserve improved not only immediately after angioplasty but also during the next month.
A new terminology for describing left and right ventricular conduction abnormalities
Authors: Hurst J. Willis 
Published: June 2007

AbstractThe words we use to describe a medical condition should match our knowledge of it. Unfortunately, at times, the words we used long ago persist after new knowledge of the subject has become apparent; so it is with left and right ventricular conduction system abnormalities. The words left or right bundle‐branch block no longer reflect our knowledge of the condition. Accordingly, this essay describes a new terminology that more accurately describes the numerous abnormalities that compose left and right ventricular conduction system block as well as their numerous subsets. A brief account of the cardiac conditions associated with the conduction defects is also presented.
Significance of the intima‐media thickness of the thoracic aorta in patients with coronary atherosclerosis
Authors: Bae Jang‐Ho , Bassenge Eberhard , Park Ki‐Rack , Kim Ki‐Young , Schwemmer Michael 
Published: June 2007

AbstractBackground: The prevalence and clinical significance of atherosclerotic aortic disease have now been documented in a variety of patient populations by use of transesophageal echo‐cardiography (TEE). There are many reports that atherosclerotic aortic plaques detected by TEE are a marker for coronary artery disease (CAD).Hypothesis: The study was undertaken to evaluate the significance of the intima‐media thickness (IMT) and formation of atherosclerotic plaques of the thoracic aorta (TA) in patients with CAD, especially in terms of a correlation between the IMT of the TA and the extent of coronary atherosclerosis.Methods: The IMT of the TA was measured using TEE. The study population comprised 100 patients (68 men, mean age 59 years). The extent of coronary atherosclerosis was divided into four groups (0,1,2,3) according to the number of coronary arteries narrowed ≤ 50%.Results: There was no significant difference in the IMT of the ascending TA according to the presence of significant (≤> 50% narrowed) coronary stenosis, but there was a significant difference in the IMT of the descending TA (1.39 vs. 1.88 mm, p = 0.005). There was a significant correlation between the extent of coronary atherosclerosis and the IMT of the ascending and descending TA (r = 0.24, p <0.05; r = 0.352, p ≥ 0.001, respectively). The plaques in the TA were seen in 7, 41, 52, and 65% of patients in Groups 0,1,2, and 3, respectively. Among atherosclerosis risk factors, hyperlipidemia was the only factor analyzed that affected the IMT of the descending TA (2.11 vs. 1.78 mm, p ≥ 0.05).Conclusion: The IMT of the TA correlates significantly with coronary atherosclerosis, and correlation of the descending TA IMT with coronary atherosclerosis is better than that of ascending TA IMT. Age is associated with coronary atherosclerosis, and TA IMT and hyperlipidemia are associated with descending TA IMT. Therefore, although TEE is not recommended for measuring TA IMT or for evaluating aortic plaques in patients with CAD, measurement of TA IMT as well as carotid artery IMT is very helpful for understanding the extent of coronary atherosclerosis.
Acute left ventricular failure after large volume pericardiocentesis
Authors: Chamoun A. , Cenz R. , Mager A. , Rahman A. , Champion C. , Ahmad M. , Birnbaum Y. 
Published: June 2007

AbstractThis paper reports on two cases of large volume pericardiocentesis followed by transient severe acute left ventricular (LV) systolic failure in the absence of any prior history of LV dysfunction. Acute LV volume overload due to inter‐ventricular volume mismatch is believed by most authors to be the cause for this phenomenon. Another plausible physiopathologic explanation is the acute increase in “wall stress” (Laplace's law) due to acute distention of the cardiac chambers secondary to a sudden increase in venous return at high filling pressures, combined with a “vacuum” effect of the evacuated pericardial space.
Atheromatous plaque cap thickness can be determined by quantitative color analysis during angioscopy: Implications for identifying the vulnerable plaque
Authors: Miyamoto Akira , Prieto Alejandro R. , Friedl Stephan E. , Lin Freeman C. , Muller James E. , Nesto Richard W. , Abela George S. 
Published: June 2007

AbstractBackground: Coronary angioscopy in acute myocardial infarction has frequently revealed disrupted yellow lesions. Furthermore, postmortem studies have demonstrated that these lesions have thin collagenous caps with underlying lipid‐rich cores.Hypothesis: We hypothesized that the yellow color is due to visualization of reflected light from the lipid‐rich yellow core through a thin fibrous cap. Thus, quantification of yellow color saturation may estimate plaque cap thickness and identify vulnerable plaques.Methods: To test this hypothesis, the feasibility of detecting cap thickness was tested using both a model of lipid‐rich plaque and human atherosclerotic plaque. The model was constructed by injecting a yellow beta‐carotene‐lipid emulsion subendothelially into normal bovine aorta. Human plaque was obtained from cadaver aorta. Digitized images were obtained by angioscopy, and percent yellow saturation was analyzed using a custom computer program. Plaque cap thickness was measured by planimetry of digitized images on stained tissue sections. Percent yellow saturation was then correlated with plaque cap thickness.Results: In the bovine model, plaque cap thickness and percent yellow saturation correlated inversely (r2 = 0.91; p = 0.0001). In human plaques, yellow saturation was significantly greater in atheromatous than in white plaques (p< 0.0004). Also, there was a high correlation between plaque cap thickness and yellow saturation at various angles of view between 40° and 90°, the greatestbetween50° and 80° (r2 = 0.75 to 0.88).Conclusion: Plaque cap thickness is a determinant of plaque color, and this can be assessed by quantitative colorimetry. Thus, plaque color by angioscopy may be useful for detecting vulnerable plaques.
Postsystolic thickening detected by doppler myocardial imaging: A marker of viability or ischemia in patients with myocardial infarction
Authors: Song Jae‐Kwan , Song Jong‐Min , Kang Duk‐Hyun , Haluska Brian , Marwick Thomas H. 
Published: June 2007

AbstractBackground: Postsystolic thickening (PST) of ischemic myocardial segments has been reported to account for the characteristic heterogeneity or regional asynchrony of myocardial wall motion during acute ischemia.Hypothesis: Postsystolic thickening detected by Doppler myocardial imaging (DMI) could be a useful clinical index of myocardial viability or peri‐infarction viability in patients with myocardial infarction (MI).Methods: Doppler myocardial imaging was recorded at each stage of a standard dobutamine stress echocardiogram (DSE) in 20 patients (16 male, 60 ± 13 years) with an MI in the territory of the left anterior descending artery. Myocardial velocity data were measured in the interventricular septum and apical inferior segment of the MI territory. Postsystolic thickening was identified if the absolute velocity of PST was higher than peak systolic velocity in the presence of either a resting PST > 2.0 cm/s or if PST doubled at low‐dose dobutamine infusion.Results: Doppler myocardial imaging data could be analyzed in 38 ischemic segments (95%), and PST was observed in 21 segments (55%), including 3 segments showing PST only at low‐dose dobutamine infusion. There was no significant difference of baseline wall motion score index (2.1 ± 0.3 vs. 2.1 ± 0.6, p = 0.77) orpeak systolic velocity (1.1 ± 1.1 vs. 1.9 ± 2.0 cm/s, p = 0.05) between segments with and without PST. Peri‐infarction ischemia or viability during DSE was more frequently observed in segments with PST than in those without (86 vs. 24%, p < 0.05). The sensitivity and specificity of P ST for prediction of peri‐infarction viability or ischemia was 82 and 81%, respectively.Conclusions: Postsystolic thickening in the infarct territory detected by DMI is closely related with peri‐infarction ischemia or viability at DSE.
Effect of bachmann's bundle pacing on atrial fibrillation: Electrophysiologic assessment
Authors: Camm A. John , Kumagai Koichiro , Tojo Hideaki , Yasuda Tomoo , Saku Keijiro 
Published: June 2007

AbstractBackground: It has recently been reported that simultaneous multisite atrial pacing, Bachmann's bundle (BB) pacing, and coronary sinus (CS) pacing are useful for preventing the induction of atrial fibrillation (AF).Hypothesis: We investigated whether a simple pacing approach via BB could reduce the induction of AF by extrastimuli (S2) from the right atrial appendage (RAA).Methods: Programmed electrical stimulation was performed from the RAA and the area of BB at the superior aspect of the atrial septum, and bipolar recordings were obtained from the RAA, BB, and CS in 14 patients.Results: In five patients, AF was induced with critically timed RAA‐S2 delivered during RAA pacing. However, AF was not induced in any patient when RAA‐S2 was delivered during BB pacing. The duration of the P wave during BB pacing was significantly shorter than that during RAA pacing and sinus rhythm (BB 80 ± 16 ms vs. RAA 106 ± 36 ms vs. sinus rhythm 100 ± 24 ms, p< 0.05). The intra‐atrial conduction time to the distal coronary sinus (CSd) caused by early S2 at the RAA was significantly reduced by BB pacing (BB 114 ± 22 ms vs. RAA 157 ± 35 ms, p< 0.001).Conclusion: Bachmann's bundle pacing reduces atrial conduction time caused by RAA‐S2 and may be useful for preventing the induction of AF.
Estrogen does not prevent endothelial dysfunction caused by cigarette smoking
Authors: Garcíia‐Fernández Raymid , Pérez‐Velasco Javier G. , Concepcion‐Milian Ariadna , Sosa Sualy , Navaroli Francisco , García‐Barreto David 
Published: June 2007

AbstractBackground: Estrogen favors endothelial function while acute tobacco use provokes dysfunction. Previous studies have not examined the effect of smoking one cigarette at different stages of the menstrual cycle.Hypothesis: Favorable actions of estrogen on endothelial function are transitorily abolished by smoking one cigarette.Methods: Brachial artery endothelium‐dependent dilation was measured noninvasively before, 10 min, and 1 h after smoking in 17 healthy premenopausal women. Studies were done in the first 3 days (early stage) and repeated between Days 9 and 13 of the menstrual cycle (middle stage). Estradiol was measured after each study.Results: At basal conditions, women in the middle stage of their cycles, when estradiol was 20 times higher than in the early stage, had significantly more endothelial‐dependent brachial dilatation. No difference in the marked depression caused by cigarette smoking was found between the two stages. One h recuperation was complete in both phases.Conclusion: Cigarette smoking abolishes the protection of circulating estrogen on endothelial function.