bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interposed abdominal compression-cardiopulmonary resuscitation and resuscitation outcome during asystole and electromechanical dissociation.
Authors: Sack J B , Kesselbrenner M B , Jarrad A 
Published: June 2012

BACKGROUND
Coronary perfusion pressure has been shown to be a significant determinant of return of spontaneous circulation from cardiac arrest during asystole and electromechanical dissociation. The addition of interposed abdominal compression to otherwise standard cardiopulmonary resuscitation (CPR) increases coronary perfusion pressure in animal and human models.

METHODS AND RESULTS
Accordingly, we conducted a randomized prospective study of 143 consecutive patients experiencing cardiac arrest in a large university-affiliated teaching hospital in whom the initial arrest rhythm was asystole or electromechanical dissociation. Patients were randomized to receive either interposed abdominal compression-CPR or standard CPR. The two end points studied were return of spontaneous circulation and 24-hour survival. In addition, we studied the complications associated with interposed abdominal compression-CPR. Sixty-nine men and 74 women with a mean age of 64 years (range, 19-97 years) were studied. The overall rate of return of spontaneous circulation was 38%. Return of spontaneous circulation was significantly greater in the group receiving interposed abdominal compression-CPR compared with the group receiving standard CPR (49% versus 28%, p = 0.01). At 24 hours, there was a significantly greater number of patients alive in the experimental group than in the control group (33% versus 13%, p = 0.009). We found no complication directly related to the procedure of interposed abdominal compression in a small subset of patients who died and underwent necropsy.

CONCLUSIONS
We conclude that the addition of interposed abdominal compression may be a useful adjunct to otherwise standard CPR that can improve resuscitation outcome of patients experiencing in-hospital cardiac arrest from asystole and electromechanical dissociation.
31P magnetic resonance spectroscopy in dilated cardiomyopathy and coronary artery disease. Altered cardiac high-energy phosphate metabolism in heart failure.
Authors: Neubauer S , Krahe T , Schindler R , Horn M , Hillenbrand H , Entzeroth C , Mader H , Kromer E P , Riegger G A , Lackner K 
Published: June 2012

BACKGROUND
The purpose of this work was to further define the value of cardiac 31P magnetic resonance (MR) spectroscopy for patients with coronary artery disease and dilated cardiomyopathy.

METHODS AND RESULTS
Blood-corrected and T1-corrected 31P MR spectra of anteroseptal myocardium were obtained at rest using image-selected in vivo spectroscopy localization, a selected volume of 85 +/- 12 cm3, and a field strength of 1.5 T. Nineteen volunteers had a creatine phosphate (CP)/ATP ratio of 1.95 +/- 0.45 (mean +/- SD) and a PDE/ATP ratio of 1.06 +/- 0.53; in four patients with left anterior descending coronary artery (LAD) stenosis, six patients with chronic anterior wall infarction, and four patients with chronic posterior wall infarction, CP/ATP and phosphodiester (PDE)/ATP ratios did not differ from those in volunteers. Twenty-five measurements of 19 patients with dilated cardiomyopathy yielded a CP/ATP of 1.78 +/- 0.51 and a PDE/ATP of 0.98 +/- 0.56 (p = NS versus volunteers). When these patients were grouped according to the severity of heart failure, however, CP/ATP was 1.94 +/- 0.43 in mild (p = NS versus volunteers) and 1.44 +/- 0.52 in severe DCM (p < 0.05), respectively. No correlation was found between CP/ATP and left ventricular ejection fraction or fractional shortening, but correlation of CP/ATP with the New York Heart Association (NYHA) class was significant (r = 0.60, p < 0.005). Six patients with dilated cardiomyopathy were studied repeatedly before and after 12 +/- 6 weeks of drug treatment leading to clinical recompensation with improvement of the NYHA status by 0.8 +/- 0.3 classes. Concomitantly, CP/ATP increased from 1.51 +/- 0.32 to 2.15 +/- 0.27 (p < 0.01), whereas PDE/ATP did not change significantly.

CONCLUSIONS
Cardiac high-energy phosphate metabolism at rest is normal in LAD stenosis and chronic myocardial infarction in the absence of heart failure. The CP/ATP ratio has low specificity for the diagnosis of dilated cardiomyopathy. However, CP/ATP correlated with the clinical severity of heart failure and may improve during clinical recompensation.
Myocardial uptake of 111In monoclonal antimyosin Fab in detecting doxorubicin cardiotoxicity in rats. Morphological and hemodynamic findings.
Authors: Hiroe M , Ohta Y , Fujita N , Nagata M , Toyozaki T , Kusakabe K , Sekiguchi M , Marumo F 
Published: June 2012

BACKGROUND
The therapeutic value of doxorubicin (DOX) is limited by its cardiotoxicity, which is dose dependent. To improve the detection of such myocardial damage, this study was designed to determine whether the 111In antimyosin antibody Fab could serve as a marker for cardiotoxicity in treated versus control rats on the basis of comparative morphological and hemodynamic findings.

METHODS AND RESULTS
DOX was administered by intravenous injection to rats at a dose of 3 mg.kg-1.week-1 for 5 weeks. Three weeks after the final injection, an intravenous dose of 111In antimyosin, 740 kBq (20 microCi), was administered, and tissue distribution of the radioisotope (percent kilogram dose per gram) was assessed in 48 hours. Myocardial uptake of radioactivity by both ventricles was more prominent in the DOX-treated rats than in control rats (p < 0.001). The heart-to-blood and heart-to-lung uptake ratios were markedly higher in the treated rats than in controls (p < 0.001). As the severity of the myocardial damage increased, there was a progressive increase in myocardial uptake. There was a strong correlation between the severity of myocardial damage and the ventricular end-diastolic pressure (r = 0.84 and r = 0.83 in the left and right ventricles, respectively). On microscopic immunoautoradiography of the DOX-treated heart, there was a specific immunolocalization of the radiotracer in the injured myocytes but no radioactivity in the control myocytes.

CONCLUSIONS
111In antimyosin antibody appears to be a useful immunoradiotracer in detecting cardiac damage induced by DOX administration and in assessing the severity of cardiotoxicity. These data reinforce the clinical observation that myocardial imaging using 111In antimyosin Fab is able to provide information to guide the course of patients receiving DOX treatment.
Use-dependent prolongation of ventricular tachycardia cycle length by type I antiarrhythmic drugs in humans.
Authors: Kidwell G A , Greenspon A J , Greenberg R M , Volosin K J 
Published: June 2012

BACKGROUND
Type I antiarrhythmic drugs block the cardiac sodium channel in a use-dependent fashion. This use-dependent behavior causes increased drug binding and consequently increased sodium channel blockade at faster stimulation rates. Importantly, the kinetics of drug association and dissociation from the sodium channel differ for each type I antiarrhythmic drug.

METHODS AND RESULTS
Thirty-five patients receiving type I antiarrhythmic drugs for the treatment of sustained monomorphic ventricular tachycardia (VT) were studied before and after drug therapy. A total of 41 drug studies were performed (lidocaine, n = 10; procainamide, n = 16; flecainide, n = 15). Sustained monomorphic VT of an identical electrocardiographic morphology was induced during the control and follow-up drug studies. During the control study, there was no significant change in the VT cycle length over time. Compared with control, significant prolongation of the onset VT cycle length was observed after treatment with procainamide and flecainide (increase of 52 +/- 24 and 80 +/- 49 msec, respectively) but not after treatment with lidocaine (increase of 8 +/- 37 msec). Additional drug-induced prolongation of the VT cycle length occurred during a 40-second observation period. This secondary "use-dependent" cycle length prolongation contributed significantly to the steady-state VT cycle length during treatment with flecainide (increase of 82 +/- 34 msec; p < 0.0001). Although a use-dependent increase in VT cycle length was observed with procainamide and lidocaine, the increase was not statistically significant (increase of 12 +/- 15 and 8 +/- 8 msec, respectively). The estimated time constants for the onset of use-dependent VT cycle length prolongation were distinctly different for the three drugs. Flecainide's prolongation of the VT cycle length occurred slowly, with an estimated time constant of 12.5 +/- 5.0 seconds. In contrast, the time course of VT cycle length prolongation was rapid during treatment with lidocaine and intermediate during treatment with procainamide (time constants of 0.52 +/- 0.51 and 4.0 +/- 1.3 seconds, respectively).

CONCLUSIONS
Use-dependent prolongation of VT cycle length during treatment with type I antiarrhythmic drugs was observed in humans. This effect was clinically significant during treatment with flecainide (i.e., the use-dependent slowing of the heart rate improved the hemodynamic tolerance of the arrhythmia). Finally, the estimated time constants for the use-dependent prolongation of VT cycle length by the three test drugs are similar to their reported in vitro time constants for use-dependent sodium channel blockade.
Indobufen in the prevention of thromboembolic complications in patients with heart disease. A randomized, placebo-controlled, double-blind study.
Authors: Fornaro G , Rossi P , Mantica P G , Caccia M E , Aralda D , Lavezzari M , Pamparana F , Milanesi G 
Published: June 2012

BACKGROUND
The purpose of this randomized, double-blind study was to evaluate the efficacy of indobufen, a reversible inhibitor of platelet cyclooxygenase, in the prevention of embolic events of cardiac origin.

METHODS AND RESULTS
One hundred ninety-six patients with heart disease and at risk for cardiogenic embolism (90 with atrial fibrillation and 106 in sinus rhythm) were randomly assigned to receive indobufen (100 mg b.i.d.) or placebo. All patients were reexamined every 3 months for the duration of the study. The primary study end points were cerebral ischemic attack (stroke and transient ischemic attack), systemic embolism, pulmonary embolism, and fatal myocardial infarction. The median duration of treatment was 854 days in the indobufen group and 865 days in the placebo group. The frequencies of primary end points (fatal and nonfatal) were 6.1% and 17.3%, respectively, in the indobufen and placebo groups (p < 0.05) for a reduction of 65% in the risk of a primary event (indobufen/placebo relative risk, 0.35; 95% confidence limits, 0.14-0.89). Adverse drug reactions, mostly gastrointestinal or hemostasis disorders, occurred in 9.2% of indobufen-treated patients.

CONCLUSIONS
The results of the study indicate that indobufen may reduce the risk of ischemic events in patients with heart disease associated with an increased risk of embolism.
8-Methoxypsoralen and longwave ultraviolet irradiation are a novel antiproliferative combination for vascular smooth muscle.
Authors: March K L , Patton B L , Wilensky R L , Hathaway D R 
Published: June 2012

BACKGROUND
Smooth muscle cell proliferation plays a major role in the genesis of restenosis after angioplasty or vascular injury. Although the effects of arterial exposure to high-energy radiation sources such as laser have been investigated in detail, the effects on vascular cells of low-intensity radiant energy in combination with photoactive agents have not been extensively characterized. Psoralens are photoactive agents that are known to be well tolerated when used in conjunction with local exposure to ultraviolet light in the A band (UVA) for the treatment of various dermatologic proliferative disorders.

METHODS AND RESULTS
We have investigated the effects of psoralen/UVA (PUVA) exposure on the proliferation of bovine aortic smooth muscle cells. Proliferation and viability were assessed over a 14-day period by trypan blue exclusion counts. Cell cycle effects were evaluated by thymidine incorporation and flow cytometry with DNA quantitation after addition of serum or platelet-derived growth factor B-chain (PDGF-BB) to subconfluent cells synchronized by serum withdrawal. No effect was observed after exposure to 8-methoxypsoralen (8-MOP) at concentrations up to 10 microM or UVA irradiation at energies up to 2.5 J/cm2. Longwave ultraviolet light and 8-MOP were found to behave synergistically as potent inhibitors of DNA synthesis in bovine aortic smooth muscle cells with the EC50 in combination ranging from 7 microM at 0.35 J/cm2 to 0.2 microM at 2.1 J/cm2. Similar antiproliferative effects were obtained by an inverse variation of dose and energy delivered. After serum stimulation, inhibition of DNA synthesis was found with either an immediate or delayed (16-hour) application of PUVA. This effect was independent of subsequent 8-MOP washout. Flow cytometry of cells treated with PUVA at several times after serum stimulation demonstrated for each time point a block in further cell cycle progression for cells in all phases of the cell cycle. Evaluation of [125I]-labeled PDGF and epidermal growth factor (EGF) binding revealed no effect of PUVA on the apparent number or affinity of PDGF binding sites present but did reveal a dose-dependent inhibition by PUVA of EGF binding. This inhibition of EGF binding occurred increasingly at higher PUVA doses than the cell cycle inhibition and accordingly did not appear to represent a critical mechanism for the antiproliferative effect. Cell counting after a single exposure to PUVA (1 microM, 1.5 J/cm2) revealed complete stasis of cell proliferation over a 28-day period without recurrent exposure. No increase in trypan-positive cells was noted over this period.

CONCLUSIONS
PUVA treatment represents a novel method for locally inhibiting proliferation of vascular smooth muscle cells without producing cytolysis.
Myocardial electrical impedance mapping of ischemic sheep hearts and healing aneurysms.
Authors: Fallert M A , Mirotznik M S , Downing S W , Savage E B , Foster K R , Josephson M E , Bogen D K 
Published: June 2012

BACKGROUND
This study was designed to examine the bulk electrical properties of myocardium and their variation with the evolution of infarction after coronary occlusion. These properties may be useful in distinguishing between normal, ischemic, and infarcted tissue on the basis of electrophysiological parameters.

METHODS AND RESULTS
The electrical impedance of myocardial tissue was studied in a sheep model of infarction. The animal model involved a one-stage ligation of the left anterior descending and second diagonal arteries at a point 40% of the distance from the apex to the base. By use of a four-electrode probe, an epicardial mapping system was developed that allowed for cardiac cycle gated and signal-averaged measurements. Subthreshold current (15 microA) was injected through two of the electrodes at frequencies of 1, 5, and 15 kHz and the induced potential measured with the other two electrodes. Epicardial maps of the left ventricle were obtained during acute infarction and at 1-, 2-, and 6-week intervals after occlusion. Results showed the average specific impedance of the myocardium before infarction to be 158 +/- 26 omega-cm independent of location on the epicardium. By 60 minutes after coronary occlusion, the specific impedance had increased by 199% (p < 0.005, n = 9); it remained elevated for up to 4 hours. One week after infarction, the specific impedance decreased to 59% of the control value (p < 0.025, n = 8). Six weeks after occlusion, the specific impedance remained low at 57% of that of the noninfarcted tissue (p < 0.005, n = 9). The phase angle of the complex impedance was also measured and revealed similar changes. The hydroxyproline content of the tissue was assayed to assess infarct healing.

CONCLUSIONS
In this animal model, impedance is a bulk electrical property of tissue that varies with the evolution of myocardial infarction. Impedance mapping revealed significantly different values for normal, ischemic, and infarcted tissue and may prove useful in better defining the electrophysiological characteristics of such tissue.
Long-term outcome of patients with depressed left ventricular function undergoing percutaneous transluminal coronary angioplasty. The NHLBI PTCA Registry.
Authors: Holmes D R , Detre K M , Williams D O , Kent K M , King S B , Yeh W , Steenkiste A 
Published: June 2012

BACKGROUND
Coronary revascularization with bypass has been shown to improve survival in patients with coronary artery disease and left ventricular dysfunction. In these patients, use of nonsurgical revascularization with percutaneous transluminal coronary angioplasty (PTCA) is increasing, although their long-term outcome has not been well delineated. The purpose of this investigation was to characterize the outcome of angioplasty in patients with decreased left ventricular function and contrast it with the results in patients with normal left ventricular function.

METHODS AND RESULTS
In the 1985-1986 National Heart, Lung, and Blood Institute's PTCA Registry, of 1,802 patients undergoing PTCA, 244 patients (13.5%) had an ejection fraction of < or = 45% (mean, 39.6 +/- 6.8%). These patients had a higher incidence of prior infarction, a longer and worse history of manifestations of coronary disease, and more extensive coronary artery disease than patients with well-preserved function; 88% and 91%, respectively, had successful dilation of at least one lesion (nonsignificant difference). However, patients with decreased left ventricular function had a decreased frequency of successful dilation of all lesions in which PTCA was attempted (76% versus 84%, p < 0.01). There were no statistically significant differences in in-hospital complications--death occurred in 0.8% and 0.7%, nonfatal myocardial infarction occurred in 4.9% and 4.5%, and emergency surgical revascularization was performed in 4.5% and 3.2%, respectively. Patients were followed for a mean of 4.1 years; during this time, patients with decreased left ventricular function had significantly worse survival and combined event-free survival. Despite this, at 4 years, 87% of the patients with a mean ejection fraction of 39.6% remained alive, and 77% were alive and had not experienced infarction or required bypass.

CONCLUSIONS
PTCA is effective in selected patients with depressed left ventricular function. Initial outcome and risk-benefit ratio are excellent. Successful dilation of at least one vessel was achieved in 88% of patients with depressed left ventricular function and in 91% of patients with more normal left ventricular function. The former group, however, had a decreased incidence of successful dilation in all lesions in which dilation was attempted (76% versus 84%, p < 0.01). There was no significant difference in in-hospital complications between the two groups. During follow-up, patients with decreased left ventricular function had worse event-free survival, although 77% were alive without infarction or bypass grafting at 4 years.
Cigarette smoking is a major risk factor for coronary spasm.
Authors: Sugiishi M , Takatsu F 
Published: June 2012

BACKGROUND
Although there have been many studies on the risk factors for coronary artery disease, the etiology of coronary artery spasm has not yet been determined.

METHODS AND RESULTS
After diagnosis by coronary arteriography, various risk factors were compared between two groups of subjects using logistic regression analysis. The vasospasm group included 175 patients with angiographically determined coronary artery spasm but no coronary artery narrowing exceeding 25% of the luminal diameter. The control group comprised 176 subjects with completely normal coronary arteries and a negative response to ergonovine maleate. The adjusted odds ratio and 95% confidence interval for smoking as a risk factor for vasospasm was 2.41 and 1.53-3.82, respectively (p < 0.05). The adjusted odds ratios for total cholesterol, low density lipoprotein, high density lipoprotein, triglycerides, diabetes mellitus, and body mass index, calculated by multivariate logistic regression analysis, were not statistically nonsignificant.

CONCLUSIONS
Smoking appears to be a major risk factor for vasospastic angina without significant coronary narrowing. The other risk factors for coronary artery disease may not contribute to coronary vasospasm.
Radiofrequency catheter ablation of ventricular tachycardia in patients with coronary artery disease.
Authors: Morady F , Harvey M , Kalbfleisch S J , el-Atassi R , Calkins H , Langberg J J 
Published: June 2012

BACKGROUND
Radiofrequency (RF) ablation of idiopathic ventricular tachycardia (VT) has been demonstrated to be highly efficacious, but the efficacy of RF ablation of VT in patients with coronary artery disease has been unknown. Therefore, the purpose of this study was to determine the feasibility of RF ablation of VT in patients with coronary artery disease.

METHODS AND RESULTS
Fifteen consecutive patients with coronary artery disease and a history of myocardial infarction underwent an attempt at RF ablation of 16 hemodynamically stable monomorphic VTs that had been documented clinically on a 12-lead ECG and that had not been successfully managed by pharmacological or device therapy. One VT was incessant, five occurred more than 25 times, and the remainder occurred two to 20 times. An additional four VTs that had not been documented clinically also were targeted for ablation. The mean age of the patients was 68 +/- 7 years (+/- SD), and their mean left ventricular ejection fraction was 0.27 +/- 0.08. The mean cycle length of the 20 VTs targeted for ablation was 438 +/- 82 msec. Ablation sites were selected based on endocardial activation mapping, pace mapping, identification of an isolated mid-diastolic potential, or concealed entrainment. Sixteen of the 20 VTs (80%) were successfully ablated in 11 of 15 patients (73%), using a mean of 4.2 +/- 3 applications of RF energy, and no recurrences of the ablated VTs occurred during 9.1 +/- 3.3 months of follow-up. The mean duration of the ablation procedures was 128 +/- 30 minutes. No complications occurred in any of the patients.

CONCLUSIONS
The results of this study demonstrate that RF ablation of hemodynamically stable VT is feasible as adjunctive therapy in selected patients with coronary artery disease.