bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased oxidative stress with elevated serum thioredoxin level in patients with coronary spastic angina
Authors: Miwa Kunihisa , Kishimoto Chiharu , Nakamura Hajime , Makita Toshinori , Ishii Katsuhisa , Okuda Nobuaki , Taniguchi Ataru , Shioji Keisuke , Yodoi Junji , Sasayama Shigetake
Published: June 2007

Background: Increased oxidative stress has been implicated in the pathogenesis of coronary vasospasm. Thioredoxin (TRX) is a redox‐active protein that is known to be induced by oxidative stress.

Hypothesis: The serum TRX level may be high in patients with coronary vasospasm.

Methods: The serum TRX level was determined using an enzyme‐linked immunosorbent assay in 21 patients with the active stage of coronary spastic angina (CSA), in 18 patients with the inactive stage of CSA (iCSA), in 24 control subjects without coronary artery disease (Control), and in 20 patients with stable effort angina (SEA).

Results: Serum TRX levels (mean ± standard deviation ng/ml) were significantly higher in CSA (64 ± 44) than in iCSA (28 ± 26), in Control (34 ± 15), and in SEA (36 ± 16). In contrast, serum α‐tocopherol levels (mg/g lipids) were significantly lower in CSA (2.8 ± 0.7) than in Control (4.0 ± 1.2) and in SEA (3.2 ± 0.4). Current smoking was significantly more prevalent in CSA (76%) than in any of the other groups. No significant correlation was found between the serum level of TRX and α‐tocopherol in the study subjects. In nine patients with CSA, the serum TRX level decreased (93 ± 41 → 41 ±35 ng/ml) and the α‐tocopherol level increased (2.7 ± 0.6 → 3.2 ± 0.7 mg/g lipids) significantly under medication with calcium entry blockers after an at least 3‐month angina‐free period.

Conclusions: Patients with coronary spastic angina had a higher serum TRX level associated with a lower serum level of antioxidant vitamin E, with redox equilibrium appearing to be related to the disease activity of coronary vasospasm in these patients. Oxidative stress may be related to the genesis of coronary vasospasm.
Clinical validation of technetium‐99m MIBI‐gated single‐photon emission computed tomography (SPECT) for avoiding false positive results in patients with left bundle‐branch block: Comparison with stress‐rest nongated SPECT
Authors: Demir Hakan , Erbay Güner , Kir K. Metin , Omurlu Kenan , Berk Fatma , Aktolun Cumali
Published: June 2007

Background: Septal perfusion defects are common on my‐ocardial perfusion single‐photon emission computed tomography (SPECT) slices in patients with left bundle‐branch block (LBBB) in the absence of coronary artery disease.

Hypothesis: The use of gated myocardial perfusion SPECT imaging in such patients should be clinically validated. The aims of this study were, therefore, to validate clinically the use of gated myocardial SPECT imaging to avoid false positive septal perfusion defects in patients with LBBB and to compare nongated and gated SPECT imaging techniques in the same patients in the same imaging session.

Methods: We performed stress‐rest myocardial perfusion SPECT and resting gated SPECT using Technetium‐99m MIBI in 25 patients with LBBB and in 6 control subjects. Stress‐rest SPECT images and end‐diastolic and end‐systolic gated SPECT slices were assessed visually and quantitatively (septum/lateral wall count ratio). Coronary angiography was performed in 15 patients with LBBB and in all 6 control subjects.

Results: Stress‐rest (nongated) SPECT slices and end‐diastolic and end‐systolic gated SPECT images were normal in all control subjects. Stress‐rest (nongated) SPECT imaging revealed septal perfusion defect in 20 (11 reversible, 9 irreversible) patients with LBBB, whereas the figures were 15 and 5 for end‐systolic and end‐diastolic gated SPECT images, respectively. Coronary angiography results were normal in all control subjects and in 15 patients with LBBB. Quantitative analysis of gated SPECT images revealed no statistically significant difference between patients with LBBB and control subjects in end‐diastolic mean septum/lateral wall count values (0.86 ± 0.19 in LBBB vs. 0.98 ± 0.15 in normal subjects, p > 0.05), but the difference was statistically significant for end‐systolic, stress, and rest values (p < 0.001 for all).

Conclusion: Gated SPECT imaging, particularly end‐diastolic images, revealed fewer false positive results and thus can be used to avoid false positive septal perfusion defects commonly seen in stress‐rest (nongated) myocardial perfusion SPECT in patients with LBBB.
Left atrial inflow propagation rate derived by transesophageal color M‐mode echocardiography is a promising index of preload
Authors: Stoddard Marcus F. , Calzada Norberto , Longaker Rita A.
Published: June 2007

Background: Pulmonary capillary wedge pressure (PCWP) is a useful index of preload and an important determinant of cardiac function.

Hypothesis: We postulated that the rate of blood propagating into the left atrium (LAIF‐PR) would be a useful measure of PCWP in critically ill patients.

Methods: Fifty‐two critically ill patients (36 men/16 women) receiving mechanical ventilation were studied by multiplane transesophageal echocardiography (TEE). Left atrial inflow propagation rate was measured in systole and diastole as the slope of the color M‐mode signal entering the left atrium from the right upper pulmonic vein.

Results: Systolic and diastolic LAIF‐PRs were feasible in 49 and 44 patients, respectively. Mean (± 1 standard deviation) LAIF‐PR in systole was 40 ± 26 cm/s (range 11‐132) and in diastole 34 ± 22 cm/s (range 5‐102). Negative correlations with PCWP (mean 19 ± 9 mmHg; range 3‐40) were good for LAIF‐PR in systole (r = −0.71, standard error of estimate [SEE] = 6 mmHg; p< 0.0001) and diastole (r = −0.71, SEE = 6 mmHg; p < 0.0001). Mean ejection fraction was 52 ± 22% (range 15‐88) and cardiac output was 6.97 ±3.52 l/min (range 2.26‐17.93). Multivariate regression showed PCWP as the only independent predictor of systolic (p < 0.0001) and diastolic (p < 0.0001) LAIF‐PR among age, heart rate, cardiac output, ejection fraction, or left atrial diameter.

Conclusions: Left atrial inflow propagation rate derived by color M‐mode TEE aligned with the right upper pulmonic vein is a promising new index of preload. Future studies addressing the determinants of LAIF‐PR, such as left atrial compliance, are needed.
The prognostic value of QTC interval and QT dispersion following myocardial infarction in patients treated with or without dofetilide
Authors: Brendorp Bente , Elming Hanne , Jun Li , Køber Lars , Torp‐Pedersen Christian
Published: June 2007

Background: Acute myocardial infarction (MI) is associated with an increased risk of death, with a 1‐year mortality close to 10% in patients discharged from hospital alive. During the first year following MI, close to 50% of deaths are assumed to be due to arrhythmic events.

Hypothesis: The study was undertaken to determine the interaction between dofetilide treatment and pretreatment QTc interval and QT dispersion regarding mortality in patients with left ventricular (LV) dysfunction and a recent MI.

Methods: The study population consisted of 894 patients with a recent MI and LV systolic dysfunction, who were randomized to receive dofetilide or placebo. The study was a sub‐study of the Danish Investigations of Arrhythmia and Mortality on Dofetilide‐MI (DIAMOND‐MI).

Results: During a minimum of 1‐year follow‐up, 261 (29%) patients died. Baseline QTc interval did not hold any prognostic value on mortality for placebo‐treated patients. When pretreatment QTc interval was < 429 ms, dofetilide resulted in a 45% reduction of mortality (hazard ratio 0.55, 95% confidence limits 0.34–0.88, p < 0.02) compared with placebo. When QTc interval was > 429 ms, dofetilide did not influence mortality significantly. This study revealed no statistically significant relation between QT dispersion, dofetilide treatment, and mortality.

Conclusion: In patients with a recent MI, LV dysfunction, and a short baseline QTc interval, dofetilide is associated with significant survival benefit. This benefit is not seen with a longer QTc interval. QT dispersion is not a risk factor in this population.
Guideline implementation in a multicenter study with an estimated 44% relative cardiovascular event risk reduction
Authors: Onat Altan , Soydan Inan , Tokgözoǧlu Lale , Sansoy Vedat , Koylan Nevres , Domaniç Nergiz , Ural Dilek
Published: June 2007

Background: The extent of cardiovascular risk reduction by implementing coronary prevention guidelines needs to be documented in various population samples.

Hypothesis: This is a multicenter study to assess the impact of risk reduction in cardiovascular events upon implementation of coronary prevention guidelines in patients with or at high risk for coronary heart disease (CHD) in the setting of clinical practice.

Methods: Enrolled volunteers numbered 2,021. Inclusion criteria postulated a minimum of 20–40% cardiovascular event risk in the subsequent 10 years as estimated from the risk table of the European Society of Cardiology (ESC) Guidelines. The estimated CHD risk reduction was assessed in terms of the Framingham risk scores at baseline and at 12 months, computed from the data of each individual. Data of the compliant group (making up half of the initial participants) at the end of the study, along with absolute and relative risk reductions in the compliant group, were analyzed.

Results: Mean global risk burden was 25.9% at baseline, reduced through multilateral preventive measures in absolute terms by 9.4% at 6 months and by 11.7% at 12 months; the latter represents a relative risk reduction of 44%. Independent variables determining the (enhanced) reduction in risk level at the end of 12 months included (high) level of baseline risk, (high) degree of compliance with treatment, younger age, female gender, smoking, and (high) baseline triglyceride/high‐density lipoprotein cholesterol (TC/HDL‐C) ratio.

While the relative reduction in patients with CHD amounted to 43%, a reduction of 46% (p < 0.001) was obtained in the setting of primary prevention. Diabetes emerged as a factor modestly limiting the extent of risk reduction. While subjects without hypertension revealed a decline of coronary risk by merely 8.7%, those with hypertension showed a decline by 12.7% (p < 0.001). Risk reductions were accompanied by a decrease of mean low‐density lipoprotein cholesterol (LDL‐C) level of 25.4%, a rise in mean HDL‐C level of 5 mg/dl, a decrease in mean systolic blood pressure of 26 mmHg. Forty‐five percent of smokers succeeded in discontinuing the habit.

Conclusion: By implementing standard prevention guidelines in the Turkish population among 1,000 compliant high‐risk men and women and among 1,000 patients with CHD, prevention of cardiovascular events could be expected in 117 persons in the subsequent 10 years.
Hyperhomocysteinemia in patients with heart failure referred for cardiac transplantation: Preliminary observations
Authors: Schofield Richard S. , Wessel Timothy R. , Walker Tracy C. , Cleeton Timothy S. , Hill James A. , Aranda Juan M.
Published: June 2007

Background: Hyperhomocysteinemia is becoming recognized as a risk factor for cardiovascular disease, yet there are limited data on the prevalence of hyperhomocysteinemia in patients with heart failure.

Hypothesis: The purpose of this study was to examine the prevalence of hyperhomocysteinemia in patients with severe heart failure and to correlate serum homocysteine levels with factors that may affect homocysteine metabolism.

Methods: Serum homocysteine levels were measured at the time of cardiac transplant evaluation in 89 consecutive patients with severe heart failure. Homocysteine levels for patients with ischemic cardiomyopathy (ICM) were compared with levels obtained in patients with nonischemic cardiomyopathy (NICM), and homocysteine levels were correlated with demographic and hemodynamic parameters as well as functional status.

Results: The mean plasma homocysteine level was increased (14.3 ± 5.3 μmol/l, normal <9.0 μmol/l) and was equivalent between patients with ICM versus NICM (14.7 ± 5.8 μmol/l vs. 13.8 ± 4.5 μmol/l, p = 0.44). Elevated homocysteine levels were seen in a large proportion (89%) of patients and were equally common to patients with NICM (94%) and ICM (85%). Serum homocysteine levels correlated with serum creatinine (r= 0.51, p<0.001), with a history of diabetes (p = 0.028), and with a history of peripheral vascular disease (p = 0.045). Only 6% of patients were receiving folic acid therapy at the time of transplant referral.

Conclusion: Hyperhomocysteinemia is common in patients with severe heart failure, and plasma homocysteine levels are uniformly elevated regardless of the etiology of heart failure. Elevated plasma homocysteine levels are likely a consequence of heart failure‐related renal insufficiency.
Predictors of cause‐specific hospital readmission in patients with heart failure
Authors: Babayan Zaruhi V. , McNamara Robert L. , Nagajothi Nagaprasad , Kasper Edward K. , Armenian Haroutune K. , Powe Neil R. , Baughman Kenneth L. , Lima João A. C.
Published: June 2007

Background: Repeated hospital readmissions are frequent and increasing over time in patients with heart failure (HF). The predictors for readmission in patients with HF are not completely understood.

Hypothesis: The study was undertaken to investigate the time course of readmission by specific cause in patients with HF, and to examine the independent effects of HF etiology and left ventricular (LV) function on cause‐specific readmissions.

Methods: A retrospective cohort of 493 consecutive patients with HF was followed for readmission for 16.5 ± 12.3 months. Ischemic etiology of HF was defined as history of myocardial infarction (MI), coronary artery bypass graft (CABG), percutaneous transluminal coronary angioplasty (PTCA), or > 70% coronary stenosis. Left ventricular function was assessed echocardiographically. Cause‐specific readmissions were classified as HF, cardiovascular disease (CVD) other than HF, and other non‐CVD.

Results: The annual readmission rate was 56.6%. Median time to readmission was 91 days, with 18.3%patients readmitted within 1 month after discharge. Ischemic etiology independently predicted all‐cause readmission: Cox hazard ratio (95%confidence interval): 1.40 (1.11‐1.79). This relationship was significant in women (1.83 [1.31‐2.55]), but not in men (1.15 [0.82‐1.62]), while readmissions were equally frequent in both genders. Similarly, ischemic etiology significantly predicted readmission for CVD in women (4.18 [2.14‐8.19]), but not in men (1.49 [0.83‐2.67]). However, LV dysfunction independently predicted readmission for recurrent HF (2.44 [1.46‐4.08]), while ischemic etiology was not predictive in either gender.

Conclusions: Readmissions for recurrent HF comprise only one‐third of total hospital readmissions in patients with HF. Ischemic etiology is a significant predictor of readmission, and most of this effect is mediated through a four‐fold increased risk of readmission for CVD other than HF in women. Readmission for recurrent HF is predicted by LV dysfunction but not by ischemic etiology. Patients with HF can be accurately risk stratified for cause‐specific readmission with available clinical data.
Effects of acute angiotensin‐converting enzyme inhibition on diastolic ventricular interaction in the dilated heart
Authors: Pepi Mauro , Tamborini Gloria , Maltagliati Anna , Guazzi Marco , Berna Giovanni , Susini Francesca , Muratori Manuela , Celeste Fabrizio
Published: June 2007

Background: The normal and dilated heart behaves as a single functional unit during preload reduction; volume unloading in the setting of diastolic ventricular interaction allows for increased left ventricular (LV) filling.

Hypothesis: We hypothesized that reduction of venous return induced by a physiologic stimulus (tilting) or by acute angiotensin‐converting enzyme (ACE) inhibitors in dilated heart is likely to have a marked and similar effect on ventricular chamber geometry and filling. This study was designed to assess how the normal and dilated heart adapts to preload reduction.

Methods: Twenty normal subjects and 20 patients with moderate heart failure due to dilated cardiomyopathy were studied with two‐dimensional and Doppler echocardiography in supine position (B) and after 40° of head‐up tilting (T). The following day, patients repeated supine (C) and tilting test (TC) after administration of captopril (25 mgs.1.). Right ventricular (RV) and LV dimensions, LV geometry, and tricuspid, mitral, and pulmonary venous flow patterns were recorded at each step of the study.

Results: In the two groups, T was associated with reduction of RV area and LV volumes; C and TC produced a similar effect on RV and LV. Changes in LV septal‐lateral diameter and anterior‐posterior diameter were different at each step of the study: during T (both groups) and after C and TC, the septallateral diameter increased slightly while the anterior‐posterior diameter decreased. During T, mitral and tricuspid peak flow velocities decreased, peak late velocities were unchanged, and the deceleration time of mitral flow increased; the systolic forward flow of pulmonary venous flow decreased, the diastolic forward flow did not change, and the difference in duration between reverse pulmonary flow and mitral peak late flow decreased; C and CT induced similar changes.

Conclusion: Preload reduction induced by tilting or by ACE inhibitors induces profound and similar effects on LV and RV dimensions, LV geometry, and biventricular filling. Reduction of RV dimension is associated with adaptation of LV geometry and decrease of LV diastolic pressure, which facilitates LV filling and pulmonary venous drainage; ACE inhibition associated with tilting exerts an additional effect on these changes. These data confirm the role of ventricular interaction in modulating LV filling in heart failure.
Detection of patients with hypertrophic cardiomyopathy at risk for paroxysmal atrial fibrillation during sinus rhythm by P‐wave dispersion
Authors: Köse Sedat , Aytemir Kudret , Sade Elif , Can Ilknur , Özer Necla , Amasyali Basri , Aksöyek Serdar , Övünç Kenan , Özmen Ferhan , Atalar Enver , Işik Ersoy , Kes Sirri , Demirtaş Ertan , Oto Ali
Published: June 2007

Background: Paroxysmal atrial fibrillation (PAF) in hypertrophic cardiomyopathy (HCM) is associated with poor prognosis. Previous studies have shown good correlation between P‐wave dispersion (Pd) and occurrence of PAF. However, Pd in patients with HCM for predicting PAF has not been studied.

Hypothesis: The aim of the study was to determine whether Pd could identify patients with HCM who are likely to suffer from PAF.

Methods: Twenty‐two patients with HCM with a history of PAF (Group 1) and 26 patients with HCM without a history of PAF (Group 2) were studied. Maximum (Pmax) and minimum (Pmin) P‐wave durations, as well as P‐wave dispersion (Pd = Pmax‐Pmin) were calculated from 12‐lead surface electrocardiograms (ECG).

Results: P‐wave dispersion was significantly different between the groups (Group 1:55 ± 6 msvs. Group 2:37 ± 8 ms; p<0.001), while Pmax (Group 1: 134 ± 11 ms vs. Group 2: 128 ± 13 ms; p = 0.06) and Pmin (Group 1: 78 ± 9 ms vs. Group 2: 81 ± 7 ms; p = 0.07) was not significantly different. Patients with a history of PAF had higher left atrial diameter than the patients without PAF (Group 1:52 ± 8 mm vs. Group 2:48 ± 10 mm; p = 0.02). A cut‐off value of 46 ms for Pd had a sensitivity of 76% and a specificity of 82% in discriminating between patients with and without PAF.

Conclusion: This study suggests that P‐wave dispersion could identify patients withHCM who are likely to develop PAF.
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

Background: 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

Background: 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

Background: 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

Background: 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

Over 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

Evidence 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

Background: 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

The 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

Background: 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

This 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

Background: 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

Background: 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

Background: 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

Background: 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.
Does initial and delayed heart rate predict mortality in patients with acute coronary syndromes?
Authors: Kovar David , Cannon Christopher P. , Bentley Jane H. , Charlesworth Andrew , Rogers William J.
Published: June 2007

Background: Lower admission heart rate (HR) is known to predict favorable outcome in ST‐elevation acute myocardial infarction. However, there are limited short‐term and no long‐term data available regarding the prediction value of the initial HR in patients with the full spectrum of acute coronary syndromes (ACS). In addition, it is unknown whether the HR obtained later during hospitalization for ACS (i.e., Day 2 or 3) remains prognostically valuable.

Hypothesis: The aim of this study was to investigate the utility of the initial and delayed HR in predicting outcome in patients with ACS.

Methods: We examined mortality at 30 days and 10 months in 10,267 patients with ACS enrolled in the oral glycoprotein IIb/IIIa inhibition with Orofiban in Patients with Unstable coronary Syndromes‐Thrombolysis In Myocardial Infarction (OPUS‐TIMI) 16 trial. Patients were stratified by HR and day from onset of ACS into the following groups: (1) HR < 60 beats/min, (2) HR 60‐80 beats/min, (3) HR 80‐100 beats/min, (4) HR > 100 beats/min; and HR obtained on (1) Day 1, (2) Day 2, and (3) Day 3.

Results: By univariate analysis, mortality at 30 days and at 10 months increased progressively with higher HR strata (1.4 vs. 1.6 vs. 2.3 vs. 5.6%, p < 0.001, and 2.6 vs. 4.2 vs. 6.5 vs. 11.8%, p < 0.001, respectively). Elevated HR remained associated with mortality irrespective of time from onset of ACS.

Conclusions: Higher initial and delayed HR is highly predictive of higher short‐ and long‐term mortality in patients with ACS. This is a simple marker that could be easily used in risk assessment.
Trends in use of herbal and nutritional supplements in cardiovascular patients
Authors: Stys Tomasz , Stys Adam , Kelly Patricia , Lawson William
Published: June 2007

Background: Use of herbs and nutritional supplements (known as naturoceuticals) is increasing in the USA, with about 50% of Americans taking naturoceuticals and spending over $10 billion per year for them. This raises concerns regarding their use instead of proven therapies, their side effects, and drug interaction potential.

Hypothesis: The study sought to characterize cardiology patients who used supplements and to examine whether their use was diagnosis or doctor dependent, whether it affected patients' compliance, and what supplements were used.

Methods: In all, 187 patients attending our cardiology clinic were interviewed, examined, and followed for up to 1 year. The users and nonusers of naturoceuticals were compared.

Results: Supplements were used in 106 patients (an average of 3.1 naturoceutical per patient). There were no significant differences in their use by gender, age, primary care doctor specialty, or cardiovascular medications prescribed (except for statins). Patients with a history of myocardial infarction, coronary revascularization, hyperlipidemia, and a family history of coronary artery disease were more likely to use the supplements. Average low‐density lipoprotein (106 vs. 108 mg/dl), average blood pressure (132/77 vs. 138/78 mmHg), and average hemoglobin (Hb)A1c (8.7 vs. 7.7%) showed no statistically significant differences between users and nonusers. Patients most commonly took multivitamins, vitamin E, vitamin C, vitamin B, folate, garlic, calcium, coenzyme Q10, and gingko.

Conclusion: This study indicates that naturoceutical use is widespread among cardiovascular patients and it is difficult to predict clinically who the users are. Fortunately, according to our limited compliance measures, it appears that the naturoceutical use has not affected patients' compliance with traditional medications. Also, possibly a detrimental interaction potential between traditional medications and naturoceuticals has been demonstrated.