bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prognostic role of plasminogen—activator—inhibitor—1 levels in treatment with streptokinase of patients with acute myocardial infarction
Authors: Sinkovič Andreta 
Published: February 2009

AbstractBackground: The antifibrinolytic effect of plasminogen—ac—tivator—inhibitor type 1 (PAI—1) may be responsible for delays in reperfusion and/or reinfarctions after streptokinase (STK) therapy in patients with acute myocardial infarction (AMI).Hypothesis: This study aimed to demonstrate the prognostic role of pretreatment PAI—1 levels for the outcome of STK therapy in patients with AMI, depending on reperfusion and/or reinfarction.Methods: The mean pretreatment PAI—1 level of 104 patients with AMI, treated with STK, determined by chro—mogenic method, was 5.8 ± 8.6 U/ml, range 0.3—66.2 U/ml. Streptokinase therapy was successful when reperfusion was achieved, as assessed noninvasively, without subsequent rein—farction; it failed when reperfusion was delayed and/or rein—farction developed.Results: Fibrinolysis with STK failed significantly in patients with elevated pretreatment PAI—1 levels (p < 0.05), especially with levels >4.0 U/ml (p<0.01). The mean pretreatment PAI—1 level was significantiy higher in unsuccessfully treated patients. Multivariate statistical testing demonstrated that among pretreatment variables, elevated PAI—1 activity was the most significant independent risk factor of failed fibrinolysis with STK.Conclusions: Among pretreatment variables, elevated pretreatment PAI‐1 activity in patients with AMI was the most significant independent risk factor of failed fibrinolysis with STK, especially at levels > 4.0 U/ml.
Medical management of significant coronary angiographic stenoses: Outcome of 60 patients observed for 433 patient years
Authors: Baird Charles L. , Crater Scott E. 
Published: February 2009

AbstractBackground: Percutaneous transluminal coronary angioplasty (PTCA) has become routine in the management of patients with stable angina pectoris and significant coronary stenoses, while medical management of such patients has declined.Hypothesis: The purpose of the present study was to evaluate the outcome of 60 patients at the Virginia Heart Institute with stable angina pectoris, observed between 1976 and 1997, who had documented evidence of severe angiographic disease but were elected to be monitored and managed in an outpatient pharmacologic rehabilitation program.Methods: Sixty patients with significant stenoses by coronary angiography (21 with single‐vessel, 26 with double‐vessel, and 13 with triple‐vessel) without impaired ventricular function, exercise‐induced ischemia or hypotension, limited exercise performance, malignant arrhythmias, or drug intolerance were enrolled in a program of pharmacologic rehabilitation and observed for an average of 7.2 years.Results: Among the 60 patients, there were 6 deaths at a mean interval of 8.3 years. Two deaths were in patients ineligible for revascularization. Another patient who died had refused revascularization after new‐onset left ventricular dysfunction, and another died intraoperatively during abdominal aortic aneurysm repair. Two patients died while exercising. Thirteen patients underwent follow‐up catheterization for worsening angina; 11 of 13 showed progression, predominantly from new lesions. Four of 11 were referred for revascularization; 7 of 11 continued medical treatment; 49 patients were stable on medical therapy throughout the period of observation.Conclusion: Medical management of selected patients with significant coronary stenoses is safe and effective.
Left ventricular myocardial remodeling and contractile state in chronic aortic regurgitation
Authors: Taniguchi Kazuhiro , Kawamaoto Tomohide , Kuki Satoru , Masai Takahumi , Mitsuno Masataka , Nakano Susumu , Kawashima Yasunaru , Matsuda Hikaru 
Published: February 2009

AbstractBackground: In chronic aortic regurgitation, eccentric hypertrophy, with combined concentric hypertrophy of the left ventricle, is an important adaptive response to volume overload, which in itself is a compensatory mechanism for permitting the ventricle to normalize its afterload and to maintain normal ejection performance (physiologic hypertrophy). However, progressive dilatation of the left ventricle leads to depressed left ventricular (LV) contractility and myocardial structural changes, including cellular hypertrophy and interstitial fibrosis (pathological hypertrophy).Hypothesis: The study was undertaken to determine the relationship between left ventricular myocardial structure and contractile function in 14 patients with chronic aortic regurgitation by cardiac catheterization and endomyocardial biopsies.Methods: Myocardial cell diameter and percent interstitial fibrosis were obtained from biopsy samples. Contractile function was evaluated from the ratio of end‐systolic wall stress to end‐systolic volume index (ESS/ESVI) and the ejection fraction‐end‐systolic stress (EF‐ESS) relationship, which was obtained from 30 normal control subjects.Results: Myocardial cell diameter correlated significantly with the ESVI (r = 0.72, p< 0.005), ejection fraction (r = −0.58, p<0.05), and ESS/ESVI (r = −0.58, p<0.05). The percent interstitial fibrosis also correlated inversely with ESS/ESVI (r = −0.71, p< 0.005). Compared with very few patients with an ESVI <70 ml/m2, the majority of patients with ESVI ≥ 70 ml/m2 had a cell diameter of ≥30 m̈m and a percent interstitial fibrosis of ≥l0%. The nine patients who had depressed contractile function, as assessed from the EF‐ESS relationship, had a higher percent interstitial fibrosis (p <0.05) than five patients showing a normal EF‐ESS relationship, despite the fact that there was no significant difference in myocardial cell diameter between them. Thus, advanced cellular hypertrophy and excessive interstitial fibrosis were significantly and independently associated with myocardial contractile dysfunction and appeared to be responsible for ventricular remodeling.Conclusion: Our findings suggest that in many patients with aortic regurgitation, eccentric hypertrophy changes its nature from physiologic to nonphysiologic during the earlier stages in the course of the disease rather than during the stage described previously.
Exercise conditioning and heart rate variability: Evidence of a threshold effect
Authors: Pardo Yosef , Noel Merz C. Bairey , Velasquez Ivan , Paul‐Labrador Maura , Agarwala Aalok , Peter C. Thomas 
Published: February 2009

AbstractBackground: A protective effect of exercise in preventing sudden cardiac death is supported by studies in healthy populations as well as in patients with cardiac disease. The mechanisms involved in this protective effect are unknown.Hypothesis: We hypothesized that exercise conditioning would beneficially alter autonomic nervous system tone, measured by heart rate variability.Methods: We prospectively studied 20 cardiac patients enrolled in a Phase 2 12‐week cardiac rehabilitation program following a recent cardiac event. The patients underwent 24 h Holter monitoring at program entry and 12 weeks later. Heart rate variability analysis was assessed for both time domain and spectral analysis.Results: The group demonstrated a modest mean conditioning effect, indicated by an average reduction in resting heart rate from 81 ± 16 to 75 ± 12 beats/min (p = 0.03), and an increase in training METS from 2.1 ± 0.4 to 3.3 ± 1.1 (p< 0.0001). Overall, 15 of 20 (75%) patients demonstrated increased total and high‐frequency power, and mean high‐frequency power was significantly increased (3.9 ± 1.4 vs. 4.4 ± 1.0 In, p = 0.05). When stratified according to the magnitude of exercise conditioning, patients achieving an increase of > 1.5 training METS demonstrated significant increases in SDNN, SDANN index, SDNN index, pNN50, total power, and high‐frequency power (all p < 0.05) (see text for explanation of abbreviations).Conclusions: Exercise conditioning improves heart rate variability in cardiac patients, particularly in patients who achieve a threshold of > 1.5 training METS increase over a 12‐week period. These study results are supportive of the concept that exercise training lowers the risk of sudden cardiac death via increased vagal tone, which likely beneficially alters ventricular fibrillatory and ischemic thresholds.
True‐Positive exercise electrocardiogram/false‐negative thallium‐201 scintigram: A proposal of a mechanism for the paradox
Authors: Madias John E. , Knez Predrag , Win Moe Thu 
Published: February 2009

AbstractA 72‐year‐old man with exertional angina had a strongly positive exercise electrocardiogram (EECG) with a negative thallium‐201 myocardial perfusion scintigram (Tl). Arteriography revealed triple‐vessel coronary artery disease, for which he underwent aortocoronary bypass grafting. Repeat EECG was negative, and it was again associated with a negative Tl. The false‐negative Tl on the first test was felt to be due to a rare phenomenon of homogeneously distributed reversible exercise‐induced myocardial ischemia, leading to a uniform radiotracer count density. The even distribution of ischemia would also be expected to render a false‐negative EECG, due to electrocardiographic cancellation, and this is frequently the case. However, in the patient presented herein, we propose that the ischemic cardiac apex rendered the EECG strongly positive because its position was not opposed by an ischemic muscular region, and thus an uncancelled ischemic ST‐segment vector was generated. This hypothesis is supported by our recent work showing the unique role of the ischemic apex (among all the other myocardial territories) in rendering the EECG positive.
Worsening of left ventricular diastolic dysfunction during exercise causes decreased exercise tolerance in hypertension
Authors: Khan Ijaz A. , Nair Vinod M. , Tekin Uygur N. , Rahmatullah Syed I. , Arora Pratheep , Mahankali Bhavani D. , Sacchi Terrence J. , Vasavada Balendu C. 
Published: February 2009

AbstractBackground: Exercise tolerance is reduced in hypertension. Hypertension affects left ventricular (LV) diastolic filling by causing abnormal relaxation and decreasing compliance.Hypothesis: This study was designed to determine whether worsening of LV diastolic dysfunction during exercise causes decreased exercise tolerance in hypertension.Methods: Left ventricular diastolic filling parameters were examined at mitral valve by Doppler echocardiography at rest and at peak exercise in hypertensive patients and were compared with those of age‐ and gender‐matched normotensive individuals. Treadmill exercise stress test was performed according to the Bruce protocol and the exercise time was recorded.Results: Exercise time was significantly shorter in the hypertensive group than that in the normotensive group (320 ± 29 vs. 446 ± 38 s, p 0.03). The hypertensive group demonstrated abnormal relaxation pattern of diastolic mitral inflow at rest, which became pseudonormal at peak exercise (E/A velocity ratio, rest 0.86 ± 0.06 vs. exercise 1.19 ± 0.09, p<0.001). The diastolic mitral inflow pattern remained normal at peak exercise in the normotensive group. The deceleration time and the pressure half time of early mitral inflow at peak exercise were significantly shorter in the hypertensive group than those in the normotensive group (deceleration time, 182 ± 20 vs. 238 ± 22 ms, p 0.02: pressure half time, 54 ± 5 vs. 70 ± 12 ms, p 0.01).Conclusions: This study demonstrates that reduced exercise tolerance in hypertension is associated with worsening of diastolic dysfunction during exercise consistent with an increase in left atrial pressure.
Hemodynamic effects and long‐term outcome of percutaneous balloon valvuloplasty in patients with mitral stenosis and atrial fibrillation
Authors: Tarka Elizabeth A. , Blitz Lawrence R. , Herrmann Howard C. 
Published: February 2009

AbstractBackground: The presence of atrial fibrillation (AF) has been identified as a predictor of a suboptimal result in some patients undergoing percutaneous balloon valvuloplasty in the treatment of symptomatic rheumatic mitral stenosis.Hypothesis: Atrial fibrillation adversely affects the short‐and long‐term outcome of patients with mitral stenosis undergoing percutaneous balloon valvuloplasty.Methods: A retrospective chart review of 104 consecutive patients with rheumatic mitral stenosis undergoing percutaneous balloon valvuloplasty was performed. A successful procedure was defined as a final mitral valve area ≤ 1.5 cm2 and the absence of a complication. Endpoints included freedom from mitral valve replacement, death, and repeat balloon valvuloplasty at 5 years.Results: A successful procedure was obtained in 89% of patients with sinus rhythm and in 78% of patients with AF (p = NS). Patients in sinus rhythm had a greater cardiac output resulting in a larger final valve area than patients in AF (1.8 vs. 1.6 cm2, p<0.05). Freedom from valve replacement, death, and repeat balloon valvuloplasty at 5 years was 75% for patients in AF and 76% for patients in sinus rhythm (p = NS). Lower postprocedure mitral regurgitation grade and absence of prior commissurotomy were the only independent predictors of event‐free survival.Conclusions: Patients with mitral stenosis and AF have lower cardiac outputs and gradients than patients with sinus rhythm, despite similar valve areas. The long‐term outcome of balloon valvuloplasty is independent of the initial cardiac rhythm.
Comparison of the efficacy and tolerability of simvastatin and atorvastatin in the treatment of hypercholesterolemia
Authors: Recto Cesar S. , Acosta Stella , Dobs Adrian 
Published: February 2009

AbstractBackground: Simvastatin and atorvastatin are effective statins for treating hypercholesterolemia.Hypothesis: The study was undertaken to compare the efficacy and tolerability of simvastatin 20 and 40 mg/day and atorvastatin 10 and 20 mg/day.Methods: In this multinational, open‐label, crossover study, 258 patients with primary hypercholesterolemia were randomized after 4 weeks of diet plus placebo to once‐daily administration of a starting dose sequence of simvastatin (20 mg) or atorvastatin (10 mg), or a higher dose sequence of simvastatin (40 mg) or atorvastatin (20 mg) for 6 weeks. Patients were then switched after a 1‐week washout to the corresponding starting or higher dose of the alternate drug for a second 6‐week period. The primary endpoint was the mean percent change from baseline to Week 6 in low‐density lipoprotein (LDL) cholesterol; percent changes from baseline in total cholesterol, high‐density lipoprotein cholesterol, triglycerides, and apolipoprotein B were also compared. Safety was assessed through adverse experiences and laboratory measurements.Results: Both statins produced statistically significant improvements in all measured plasma lipids and lipoproteins. The main treatment comparison showed no statistically significant difference in changes in LDL cholesterol and triglycerides, whereby the overall effects were comparable when doses of 20 mg and 40 mg of simvastatin were compared with atorvastatin 10 mg and 20 mg. The mean percent reductions for LDL cholesterol from baseline to Week 6 ranged from 35–42% for the entire study cohort. An LDL cholesterol level ≤ 130 mg/dl (3.4 mmol/l) was achieved in approximately 70% of patients treated with both drugs in this study. Simvastatin and atorvastatin were well tolerated at the doses studied.Conclusion: In patients with hypercholesterolemia, the most commonly used doses of simvastatin and atorvastatin produced similar changes in LDL cholesterol and achieved an LDL cholesterol level ≤ 130 mg/dl (3.4 mmol/l) in a similar number of patients. Both statins were well tolerated.
Intracardiac masses detected by echocardiography: Case presentations and review of the literature
Authors: Lobo Arlene , Lewis Jannet F. , Conti C. Richard 
Published: February 2009

AbstractIntracardiac masses are often diagnosed by transthoracic echocardiography (TTE). Transesophageal echocardiography (TEE) improves overall visualization of masses, especially those located in the posterior cardiac structures. Masses in the heart are most commonly due to thrombi or valvular vegetations; however, a variety of tumors may also present as cardiac masses on echocardiography. Tumors of the heart most commonly occur in the setting of metastatic disease, usually from malignancies of the breast, lung, or from malignant melanoma. Primary cardiac tumors occur much less frequently and are usually benign. Atrial myxomas constitute nearly one‐half of reported primary cardiac tumors. The following discussion details the findings of five cases that illustrate the spectrum of intracardiac rumors detected by echocardiography and reviews the relevant literature.
Postoperative troponin I values: Insult or injury?
Authors: Horvath Keith A. , Parker Michelle A. , Frederiksen James W. , Palmer Arthur S. , Fullerton David A. 
Published: February 2009

AbstractBackground: Troponin I (TnI) is increasingly employed as a highly specific marker of acute myocardial ischemia. The value of this marker after cardiac surgery is unclear.Hypothesis: The purpose of this study was to measure serum TnI levels prospectively at 1, 6, and 72 h after elective cardiac operations. In addition, TnI levels were measured from the shed mediastinal blood at 1 and 6 h postoperatively. Serum values were correlated with cross clamp time, type of operation, incidence of perioperative myocardial infarction, as assessed by postoperative electrocardiograms (ECG) and regional wall motion, as documented by intraoperative transesophageal echocardiography (TEE).Methods: Sixty patients underwent the following types of surgery: coronary artery bypass graft (CABG) (n = 45), valve repair/replacement (n = 10), and combination valve and coronary surgery (n = 5). Myocardial protection consisted of moderate systemic hypothermia (30–32°C), cold blood cardioplegia, and topical cooling for all patients.Results: Of 60 patients, 57 (95%) had elevated TnI levels, consistent with myocardial injury, 1 h postoperatively. This incidence increased to 98% (59/60) at 6 h postoperatively. There was a positive correlation between the length of cross clamp time and initial postoperative serum TnI (r = 0.70). There was no difference in the serum TnI values whether or not surgery was for ischemic heart disease (CABG or CABG + valve versus valve). There were no postoperative myocardial infarctions as assessed by serial ECGs. There was no evidence of diminished regional wall motion by TEE.Levels of TnI in the mediastinal shed blood were greater than assay in 58% (35/60) of the patients at 1 h and in 88% (53/60) at 6 h postoperatively. Patients who received an auto‐transfusion of mediastinal shed blood (n = 22) had on average a 10‐fold postoperative increase in serum TnI levels between 1 and 6 h. Patients who did not receive autotransfusion average less than doubled their TnI levels over the same interval. At 72 h, TnI levels were below the initial postoperative levels but still indicative of myocardial injury.Conclusion: Postoperative TnI levels are elevated after all types of cardiac surgery. There is a strong correlation between intraoperative ischemic time and postoperative TnI level. Further elevation of TnI is significantly enhanced by reinfusion of mediastinal shed blood. Despite these postoperative increases in TnI, there was no evidence of myocardial infarction by ECG or TEE. The postoperative TnI value is even less meaningful after autotransfusion of shed mediastinal blood.
Emergent angioplasty prevents left ventricular dilation in patients with acute anterior wall myocardial infarction and cardiogenic shock
Authors: Iwamori Kiyotake , Sakata Konomi , Kurihara Hiroaki , Yoshino Hideaki , Ishikawa Kyozo 
Published: February 2009

AbstractBackground: Percutaneous transluminal coronary angioplasty (PTCA) reduces in‐hospital mortality and improves long‐term outcome in patients with acute myocardial infarction (MI) complicated by cardiogenic shock. However, no study has evaluated the effects of different reperfusion therapies on left ventricular (LV) dimension and cardiac function in long‐term survivors of MI with cardiogenic shock.Hypothesis: We investigated the effects of PTCA on the development of LV dilation in patients who survived MI complicated by cardiogenic shock.Methods: We studied 34 patients with a first MI and cardiogenic shock in whom two‐dimensional echocardiography was performed immediately after admission and 1 month after infarction. Group A consisted of 17 patients who underwent emergent PTCA during the acute phase of MI, and Group B consisted of 17 patients who did not undergo PTCA. We also studied 119 patients with a first uncomplicated acute anterior MI, including 53 who underwent PTCA (Group C) and 66 who did not (Group D). The length and wall thickness of the infarcted and noninfarcted endocardial segments were determined immediately after MI and 1 month later, and LV ejection fraction (LVEF) was measured during the chronic phase.Results: The lengths of the infarcted and noninfarcted endocardial segments were significantly greater in Group B than in the other three groups (p < 0.05). The LVEF was significantly lower in Group B than in the other three groups (p < 0.05).Conclusions: We conclude that PTCA performed in patients during the acute phase of MI complicated by cardiogenic shock lowers in‐hospital mortality and prevents both LV dilation and a decrease in LVEF.
Assessment of left ventricular systolic function in patients with idiopathic mitral valve prolapse using dobutamine stress echocardiography
Authors: Tikiz Hakan , Balbay YÜCel , Kural Tevfik , Göksel Siber 
Published: February 2009

AbstractBackground: Some previous studies performed with radionuclide ventriculography and thallium scintigraphy reported that patients with idiopathic mitral valve prolapse (MVP) had some degree of left ventricular (LV) systolic dysfunction and that this dysfunction was more commonly found in symptomatic patients.Hypothesis: The aim of the present prospective study was to investigate LV systolic function and its relationship with symptoms in patients with MVP with dobutamine stress test without associated certain mitral regurgitation and coronary artery disease.Methods: Thirty‐three patients with echocardiographically diagnosed idiopathic MVP were enrolled into the study and were divided into two groups as symptomatic (MVP‐s) and asymptomatic (MVP‐a). Patients underwent dobutamine stress echocardiography (DSE) to determine wall motion abnormalities and ejection fraction (EF) changes during rest state and increased heart rates. Results were compared with the DSE findings of 25 healthy individuals.Results: Symptomatic patients (MVP‐s) had lower EFs during the pretest period than the control group (59.0 ± 4.8% and 68.3 ± 5.7%, respectively, p < 0.05). Basal wall motion abnormalities were found in one patient in the MVP‐a group (6%) and in two patients in the MVP‐s group (12%). During DSE, new wall motion abnormalities (inferoapical dyskinesia) occurred in two patients in the MVP‐s group at submaximal heart rates. For EF values calculated when patients reached submaximal heart rate, the MVP‐s group showed only a 2.7 ± 3.1% increase from baseline values. This increase was 5.1 ± 3.8% in the MVP‐a group and 9.3 ± 4.3% in the control group (p < 0.05 between MVP‐s and control groups).Conclusion: There is a close relationship between symptoms and ventricular function in patients with idiopathic MVP, and although many asymptomatic patients had nearly normal LV function, a subgroup of symptomatic patients showed diminished LV function and wall motion abnormalities.
Effects of theophylline on exercise indices in a patient with chronotropic incompetence
Authors: Dixoniv William C. , Bauch Terry D. 
Published: February 2009

AbstractSeveral investigators have documented the successful use of oral sustained‐release theophylline in treating symptomatic bradycardia and sick sinus syndrome. This paper reports a case of chronotropic incompetence in which specific exercise indices, including the chronotropic response index, were used to measure the therapeutic efficacy of theophylline.