Myocardial Ischemia (myocardial + ischemia)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Myocardial Ischemia

  • acute myocardial ischemia


  • Selected Abstracts


    Proximal Coronary Hemodynamic Changes Evaluated by Intracardiac Echocardiography during Myocardial Ischemia and Reperfusion in a Canine Model

    ECHOCARDIOGRAPHY, Issue 3 2008
    Beibei Han M.D.
    Background: The purpose of this study was to assess whether the dynamic changes in coronary flow velocity and coronary flow velocity reserve (CFVR) by intracardiac echocardiography (ICE) within proximal coronary arteries are related to myocardial perfusion status and infarct size in a myocardial ischemia-reperfusion injury model. Methods: In 14 dogs, left anterior descending coronary artery (LAD) was ligated for 2 hours followed by 2 hours reperfusion. Coronary flow velocity was obtained by ICE within coronary arteries at baseline, and at the end of both occlusion and reperfusion period. The CFVR was calculated as the ratio of hyperemic to resting peak diastolic velocity (PDV). Myocardial perfusion was evaluated by real time myocardial contrast echocardiography (MCE). The infarct area was detected by triphenyltetrazolium chloride (TTC) staining and expressed as the percentage of the whole left ventricular (LV) area. Results: CFVR significantly decreased both in proximal LAD and left circumflex (LCx) artery at the end of occlusion, and did not recover at the end of reperfusion. However, no significant difference in flow parameters was observed between dogs with myocardial perfusion defect and those without. CFVR in LAD at the end of reperfusion did not correlate with the infarct size (r =,0.182, P = NS) either. Conclusions: Decreased CFVR detected by ICE occurs both in ischemic and in nonischemic proximal arteries during myocardial ischemia and early stage of reperfusion. This change in CFVR has poor correlation with the extent of microvascular impairment and cannot be used to predict infarct size. [source]


    Is Left Ventricular Diastolic Thickening Documented During Dobutamine and Pacing Stress Echocardiography Related to Myocardial Ischemia?

    ECHOCARDIOGRAPHY, Issue 1 2002
    An Animal Model Study
    Transient increase in diastolic wall thickness (pseudohypertrophy) during pacing stress echocardiography has been reported in normal myocardium. To evaluate the occurrence of pseudohypertrophy and to investigate the contribution of myocardial ischemia on its production during pacing and dobutamine stress echocardiography, we produced a physiologically significant coronary stenosis in 14 open chest dogs. The stenosis in the circumflex artery was measured by quantitative coronary angiography (range: 50% to 89% reduction in luminal diameter), and no resting segmental wallmotion abnormalities were observed by epicardial echocardiography (short-axis, papillary level). In each study, dobutamine (5,40 ,g/kg/min) and pacing (up to 260 beats/min) were performed randomly. Positivity of stress echocardiography tests was quantitatively determined by a significant (P < 0.05) reduction or failure to increase in absolute and percent systolic wall thickening in the myocardial area supplied by the stenotic artery as compared to the left anterior descending (LAD) artery-related areas. Diastolic wall thickness and left ventricular diastolic area were compared before and after each stress test in the circumflex and LAD artery-related regions. Pseudohypertrophy was observed in 57% and 86% of dogs for pacing and dobutamine, respectively, in the circumflex region, and in 50% and 64% in the LAD region. Despite its increased incidence in the circumflex region, the augmented diastolic wall thickness did not correlate with coronary stenosis severity or stress test positivity, but correlated inversely with changes in left ventricular diastolic area. In addition, it correlated directly with changes in heart rate only for pacing. In conclusion, pseudohypertrophy was a frequent finding during pacing and dobutamine stress echocardiography tests but was not related to myocardial ischemia in this animal model. [source]


    Do Diabetic Patients Have Higher In-hospital Complication Rates When Admitted from the Emergency Department for Possible Myocardial Ischemia?

    ACADEMIC EMERGENCY MEDICINE, Issue 3 2000
    Peter B. Richman MD
    Abstract Objective: To compare in-hospital complication rates for diabetic and nondiabetic patients admitted from the emergency department (ED) for possible myocardial ischemia. Methods: This was a prospective, observational study of consecutive consenting patients presenting to a suburban university hospital ED during study hours with typical and atypical symptoms consistent with cardiac ischemia. Demographic, historical, and clinical data were recorded by trained research assistants using a standardized, closed-question, data collection instrument. Inpatient records were reviewed by trained data abstractors to ascertain hospital course and occurrence of complications. Final discharge diagnosis of acute myocardial infarction (AMI) was assigned by World Health Organization criteria. Categorical and continuous data were analyzed by chi-square and t-tests, respectively. All tests were two-tailed with alpha set at 0.05. Results: There were 1,543 patients enrolled who did not have complications at initial presentation; 283 were diabetic. The rule-in rate for AMI was 13.8% for nondiabetic patients and 17.7% for diabetic patients (p = 0.09). Times to presentation were similar for nondiabetic vs diabetic patients [248 minutes (95% CI = 231 to 266) vs 235 minutes (95% CI = 202 to 269); p = 0.32]. Nondiabetic patients tended to be younger [56.6 years (95% CI = 55.8 to 57.4) vs 61.6 years (95% CI = 60.2 to 63.1); p = 0.001] and were less likely to be female (34.3% vs 48.1%; p = 0.001). The two groups had similar prevalences for initial electrocardiograms diagnostic for AMI (5.5% vs 7.4%; p = 0.21). There was no significant difference between nondiabetic and diabetic patients for the occurrence of the following complications after admission to the hospital: congestive heart failure (1.3% vs 1.1%, p = 0.77); nonsustained ventricular tachycardia (VT) (1.3% vs 1.2%, p = 0.93); sustained VT (1.2% vs 1.1%, p = 0.85); supraventricular tachycardia (1.7% vs 3.2%, p = 0.12); bradydysrhythmias (1.9% vs 1.1%, p = 0.33); hypotension necessitating the use of pressors (0.9% vs 1.1%, p = 0.76); cardiopulmonary resuscitation (0.2% vs 0.7%, p = 0.10); and death (0.3% vs 0.7%, p = 0.34). One or more complications occurred with similar frequencies for patients in the two groups (6.3% vs 5.7%; p = 0.70). Conclusions: No statistically significant difference was found in the post-admission complication rates for initially stable diabetic vs nondiabetic patients admitted for possible myocardial ischemia. Based on these results, the presence or absence of diabetes as a comorbid condition does not indicate a need to alter admitting decisions with respect to risk for inpatient complications. [source]


    Demonstration of Myocardial Ischemia by an Internal Loop Recorder

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2000
    STEPHEN C. VLAY
    VLAY, S.C., et al.: Demonstration of Myocardial Ischemia by an Internal Loop Recorder. An internal loop recorder (ILR) implanted to evaluate syncope was activated during an episode of chest pain. Analysis of the recorded event revealed a marked increase in the amount of ST-segment depression over baseline. In addition to rhythm analysis, the ILR may be able to assess myocardial ischemia. Further refinements of filtering may make analysis more accurate. [source]


    Dobutamine Stress Cardiac Magnetic Resonance Imaging to Detect Myocardial Ischemia in Women

    PREVENTIVE CARDIOLOGY, Issue 3 2008
    Subha V. Raman MD
    This study sought to evaluate dobutamine stress cardiac magnetic resonance imaging (DCMRI) in women with abnormal stress nuclear testing results. Women with findings on stress nuclear exams, including electrocardiography and/or perfusion, thought to require further evaluation with invasive coronary angiography were prospectively enrolled. Multiplane cine imaging was obtained at rest and at each stage of inotropic stress with atropine as needed to achieve target heart rate. DCMRI results were compared with stress nuclear and invasive cardiac catheterization results. Of 23 patients enrolled successfully, 22 completed DCMRI examination without complications. In all cases, DCMRI imaging demonstrated appropriate stress response with no ischemia despite abnormalities on stress nuclear testing. In the 18 patients who also underwent invasive coronary angiography, no significant obstructive disease was identified. DCMRI may be a useful alternative to stress nuclear examination in women; larger studies are warranted to determine its potential to more accurately predict obstructive coronary artery disease. [source]


    Electrocardiographic Body Surface Mapping: Potential Tool for the Detection of Transient Myocardial Ischemia in the 21st Century?

    ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2009
    Monique R. Robinson D.Phil
    Coronary artery disease (CAD) is one of the leading causes of cardiovascular mortality and morbidity worldwide. CAD presents as a wide spectrum of clinical disease from stable angina to ST segment elevation myocardial infarction. The 12-lead electrocardiogram (ECG) has been the main tool for the diagnosis of these events for almost a century but is limited in its diagnostic ability. For patients with suspected angina, the exercise tolerance test is often used to provoke and detect stress-induced ischemia but does not provide a definitive answer in a substantial proportion of patients. Body surface mapping (BSM) is a technique that samples multiple points around the thorax to provide a more comprehensive electrocardiographic data set than the conventional 12-lead ECG. Moreover, recent preliminary data demonstrate that BSM can detect and display transient regional myocardial ischemia in an intuitive fashion, employing subtraction color mapping, making it potentially valuable for diagnosing CAD causing transient regional ischemia. Research is ongoing to determine the full extent of its utility. [source]


    Lack of Impact of Myocardial Ischemia on the Signal-Averaged ECG Assessment by Time-Domain Analysis

    ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2002
    Michael A. E. Schneider M.D.
    Background: Late potentials represent an arrhythmogenic substrate in chronically infarcted myocardium. It is hypothesized that acute transient ischemia enhances anisotropic electrical ventricular activation and facilitates reentry mechanisms. Study aim was the prospective assessment of the impact of dipyridamole-induced myocardial ischemia on the signal-averaged ECG. Methods: Dipyridamole stress thallium-201 SPECT imaging was utilized to avoid noise contamination of the signal-averaged ECG from exercise and to document evidence and localization of myocardial ischemia or persistent perfusion defects in 68 patients with suspected coronary artery disease. Before and during dipyridamole-induced vasodilatation serial signal-averaged ECG was performed to evaluate the influence of transient ischemia on the occurrence of late potentials. Results: There was a significant difference between heart rate at rest and heart rate under dipyridamole influence in patients with inducible ischemia (70 13 vs. 87 13; P < 0.0001) in contrast to patients without dipyridamole-induced ischemia (74 20 vs. 80 16; n.s.). The number of averaged beats and achieved noise level was comparable between both groups. Thirty-three of 68 patients (49%) revealed dipyridamole-induced ischemia; however, no changes of the SAECG parameters, such as QRS, RMS, LAS at 25,250 and 40,250 Hz bandpass filtering in the leads X, Y, Z and vector magnitude, respectively, were observed as a result of ischemia. Conclusion: These results suggest that transient myocardial ischemia does not affect the signal-averaged ECG. Clinically, the signal-averaged ECG analysis seems not to be helpful in identifying patients with silent ischemia. A.N.E. 2002;7(3):191,197 [source]


    Platelet activation, myocardial ischemic events and postoperative non-response to aspirin in patients undergoing major vascular surgery

    JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 10 2007
    S. RAJAGOPALAN
    Summary.,Objectives:,Myocardial ischemia is the leading cause of postoperative mortality and morbidity in patients undergoing major vascular surgery. Platelets have been implicated in the pathogenesis of acute thrombotic events. We hypothesized that platelet activity is increased following major vascular surgery and that this may predispose patients to myocardial ischemia.Methods:,Platelet function in 136 patients undergoing elective surgery for subcritical limb ischemia or infrarenal abdominal aortic aneurysm repair was assessed by P-selectin expression and fibrinogen binding with and without adenosine diphosphate (ADP) stimulation, and aggregation mediated by thrombin receptor-activating peptide and arachidonic acid (AA). Cardiac troponin-I (cTnI) was performed.Results:,P-selectin expression increased from days 1 to 3 after surgery [median increase from baseline on day 3: 53% (range: ,28% to 212%, P < 0.01) for unstimulated and 12% (range: ,9% to 45%, P < 0.01) for stimulated]. Fibrinogen binding increased in the immediate postoperative period [median increase from baseline: 34% (range: ,46% to 155%, P < 0.05)] and decreased on postoperative day 3 (P < 0.05). ADP-stimulated fibrinogen binding increased on day1 (P < 0.05) and thereafter decreased. Platelet aggregation increased on days 1,5 (P < 0.05). Twenty-eight (21%) patients had a postoperative elevation (> 0.1 ng mL,1) of cTnI. They had significantly increased AA-stimulated platelet aggregation in the immediate postoperative period and on day 2 (P < 0.05), and non-response to aspirin (48% vs. 26%, P = 0.036).Conclusions:,This study has shown increased platelet activity and the existence of non-response to aspirin following major vascular surgery. Patients with elevated postoperative cTnI had significantly increased AA-mediated platelet aggregation and a higher incidence of non-response to aspirin compared with patients who did not. [source]


    Moricizine Induced Increase in Pacing Threshold

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1p1 2003
    JOHN P. GIROD
    GIROD, J.P., et al.: Moricizine Induced Increase in Pacing Threshold. A 72-year-old woman who was experiencing incessant ventricular tachycardia and recurrent automatic implantable cardioverter defibrillator (AICD) firing despite amiodarone therapy was referred to the Cleveland Clinic Foundation. Myocardial ischemia and infarction were ruled out by standard means. Several antiarrhythmic medications were tried previously without success. Moricizine, 200 mg three times daily, was initiated and controlled the ventricular tachycardia. However, after the dose of moricizine was titrated upward, the patient became symptomatically bradycardic and the ECG exhibited 2:1 block of her paced rhythm and an increased ventricular pacing threshold. (PACE 2003; 26[Pt. I]:110,111) [source]


    Dobutamine stress surface mapping of myocardial ischemia in Kawasaki disease

    PEDIATRICS INTERNATIONAL, Issue 3 2001
    Nobuyuki Takechi
    Abstract Background: To detect and localize myocardial ischemia, a method that does not require physical exertion is sometimes needed in children with Kawasaki disease. Methods: Dobutamine stress body surface mapping was performed in 115 children with a history of Kawasaki disease (58 without coronary artery lesions, 40 who had coronary lesions without myocardial ischemia and 17 with myocardial ischemia). The maximum infusion rate of dobutamine was 30 ,g/kg per min. Myocardial ischemia was diagnosed by the presence of an area of hypoperfusion on scintigraphy at rest and/or an increase in hypoperfusion during a dobutamine stress test compared with resting scintigraphy. We studied the number of leads that showed significant ST depression on the isopotential map (nST), the number of the row containing the lead with the smallest negative value on the isointegral map (Imin), and the localization of myocardial ischemia on the isointegral map. Based on findings in patients without coronary artery lesions, we defined the criteria for detecting myocardial ischemia as nST , 1 and Imin, 4. Results: The sensitivity of detecting myocardial ischemia was 94.1% using nST and 41.7% using Imin, while the specificity of these methods was 98.9 and 96.9%, respectively. The localization of myocardial ischemia on stress body surface mapping was 100% concordant with that determined by stress myocardial scintigraphy. Conclusions: Dobutamine stress body surface mapping for the detection of myocardial ischemia is a non-invasive, more convenient and repeatable test compared with exercise myocardial scintigraphy and it is a more objective test compared with exercise echocardiography. Dobutamine stress body surface mapping is useful for the identification and localization of silent myocardial ischemia in pediatric patients with Kawasaki disease, especially those who cannot perform tests involving physical exercise. [source]


    Overview of the relationship between ischemia and congestive heart failure

    CLINICAL CARDIOLOGY, Issue S4 2000
    PH.D., Willem J. Remme M.D.
    Abstract Ischemic heart disease is the principal etiology of heart failure in the Western world. Myocardial ischemia is important in cardiac remodeling, a process that leads to a progressive change in the shape and size of the heart and significantly worsens the prognosis of patients with heart failure. Preventing ischemic events, therefore, is an important goal in the management of patients with coronary artery disease. Statins have been shown to reduce the number of ischemic events in these patients, whereas the benefit of beta-blocker and aldosterone antagonist therapy on ischemic causes of heart failure remains unclear. Several large trials involving patients with asymptomatic left ventricular dysfunction after myocardial infarction or heart failure have shown that angiotensin-converting enzyme (ACE) inhibitors reduce the incidence of progressive heart failure, death, and ischemic events, thus establishing ACE inhibitors as first-line therapy for these patients. Other lines of evidence have suggested that ACE inhibitor therapy may also benefit patients with preserved left ventricular function, a hypothesis that is being evaluated in three large, controlled, randomized trials. One of these trials, the Heart Outcomes Prevention Evaluation (HOPE) study, was terminated prematurely because it demonstrated the significant positive effects of the ACE inhibitor ramipril on cardiovascular outcomes in patients with coronary artery disease and preserved left ventricular function. A growing body of data confirms the relationship between ischemia and heart failure and the benefits of ACE inhibitor treatment in a broad range of high-risk patients. [source]


    Thaliporphine protects ischemic and ischemic-reperfused rat hearts via an NO-dependent mechanism

    DRUG DEVELOPMENT RESEARCH, Issue 3 2001
    Li-Man Hung
    Abstract In ischemia or ischemia-reperfusion (I/R), nitric oxide (NO) can potentially exert several beneficial effects. Thaliporphine, a natural alkaloid with Ca2+ channel-activating and Na+/K+ channel-blocking activities, increased NO levels and exerted cardioprotective action in ischemic or I/R rats. The role of NO in the cardioprotective actions of thaliporphine was assessed. The severity of rhythm disturbances and mortality in anesthetized rats with either coronary artery occlusion for 30 min, or 5 min followed by 30-min reperfusion, were monitored and compared in thaliporphine- vs. placebo-treated groups. Thaliporphine treatment significantly increased NO and decreased lactate dehydrogenase (LDH) levels in the blood during the end period of ischemia or I/R. These changes in NO and LDH levels by thaliporphine were associated with a reduction in the incidence and duration of ventricular tachycardia (VT) and ventricular fibrillation (VF) during ischemic or I/R period. The mortality of animals was also completely prevented by 1 10,8 moles/kg of thaliporphine. In animals subjected to 4 h of left coronary artery occlusion, 1 10,7 moles/kg of thaliporphine dramatic reduced cardiac infarct zone from 46 6% to 7.1 1.9%. Inhibition of NO synthesis with 3.7 10,6 moles/kg of N, -nitro-L-arginine methyl ester (L-NAME) abolished the beneficial effects of thaliporphine during 30 min or 4 h myocardial ischemia. However, the antiarrhythmic activity and mortality reduction efficacy of thaliporphine during reperfusion after 5 min of ischemia was only partially antagonized by L-NAME. These results showed that thaliporphine efficiently exerted the cardioprotections either in acute or prolonged coronary artery occlusion or occlusion-reperfusion situations. The fact that thaliporphine induced cardioprotective effects were abrogated by L-NAME indicates that NO is an important mediator for the cardioprotective effects of thaliporphine in acute or prolonged ischemia, whereas antioxidant activities may contribute to the protection of I/R injury. Drug Dev. Res. 52:446,453, 2001. 2001 Wiley-Liss, Inc. [source]


    Proximal Coronary Hemodynamic Changes Evaluated by Intracardiac Echocardiography during Myocardial Ischemia and Reperfusion in a Canine Model

    ECHOCARDIOGRAPHY, Issue 3 2008
    Beibei Han M.D.
    Background: The purpose of this study was to assess whether the dynamic changes in coronary flow velocity and coronary flow velocity reserve (CFVR) by intracardiac echocardiography (ICE) within proximal coronary arteries are related to myocardial perfusion status and infarct size in a myocardial ischemia-reperfusion injury model. Methods: In 14 dogs, left anterior descending coronary artery (LAD) was ligated for 2 hours followed by 2 hours reperfusion. Coronary flow velocity was obtained by ICE within coronary arteries at baseline, and at the end of both occlusion and reperfusion period. The CFVR was calculated as the ratio of hyperemic to resting peak diastolic velocity (PDV). Myocardial perfusion was evaluated by real time myocardial contrast echocardiography (MCE). The infarct area was detected by triphenyltetrazolium chloride (TTC) staining and expressed as the percentage of the whole left ventricular (LV) area. Results: CFVR significantly decreased both in proximal LAD and left circumflex (LCx) artery at the end of occlusion, and did not recover at the end of reperfusion. However, no significant difference in flow parameters was observed between dogs with myocardial perfusion defect and those without. CFVR in LAD at the end of reperfusion did not correlate with the infarct size (r =,0.182, P = NS) either. Conclusions: Decreased CFVR detected by ICE occurs both in ischemic and in nonischemic proximal arteries during myocardial ischemia and early stage of reperfusion. This change in CFVR has poor correlation with the extent of microvascular impairment and cannot be used to predict infarct size. [source]


    Dobutamine Stress Magnetic Resonance Imaging

    ECHOCARDIOGRAPHY, Issue 3 2007
    F.A.C.C., F.A.C.P., F.A.S.E., Pairoj Rerkpattanapipat M.D.
    Measurements of left ventricular function with cardiovascular magnetic resonance (CMR) at rest and during intravenous dobutamine are useful for identifying myocardial ischemia, viability, and the risk of subsequent cardiovascular events. Without ionizing radiation, intravascular iodinated contrast administration, or acoustic window limitations, CMR has emerged as a useful adjunct to transthoracic echocardiography for assessing patients with or suspected of having coronary artery disease. [source]


    Vasodilator Stress Induces Infrequent Wall Thickening Abnormalities Compared to Perfusion Defects in Mild-to-Moderate Coronary Artery Disease: Implications for the Choice of Imaging Modality with Vasodilator Stress

    ECHOCARDIOGRAPHY, Issue 4 2004
    M.R.C.P., Ph.D., Prem Soman M.D.
    Background: Experimental evidence suggests that although vasodilator stress agents consistently induce regional flow disparity between stenosed and normal coronary vascular beds, the occurrence of functional myocardial ischemia is infrequent, especially in mild-to-moderate coronary artery stenosis. Thus, it is hypothesized that dipyridamole infusion, even at high doses, will result in a disproportionately higher frequency of perfusion defects compared to regional wall thickening abnormalities. Methods: We performed simultaneous high-dose (0.84 mg/kg) dipyridamole stress echocardiography (Echo) and Tc-99m sestamibi SPECT (MIBI, methoxyisobutyl isonitrile) in 46 patients with coronary artery diameter stenosis >50% and ,90% in one or two epicardial coronary arteries, and no previous myocardial infarction. Results: Of a total of 828 segments, MIBI showed 97 reversible defects while Echo showed only 23 reversible wall thickening abnormalities. Of the 97 segments with reversible MIBI defects, only 13 (13%) showed simultaneous reversible wall thickening abnormalities during dipyridamole infusion. There were 24 patients with MIBI defects, of whom 10 (41%) showed a corresponding wall thickening abnormality. The sensitivity of MIBI and Echo for the detection of coronary artery disease was 52% and 21%, respectively (P = 0.001). Conclusion: This suggests that vasodilator stress is not optimally suited for use with techniques that use regional wall thickening abnormality as a marker of ischemia for the diagnosis of coronary artery disease. (ECHOCARDIOGRAPHY, Volume 21, May 2004) [source]


    Is Left Ventricular Diastolic Thickening Documented During Dobutamine and Pacing Stress Echocardiography Related to Myocardial Ischemia?

    ECHOCARDIOGRAPHY, Issue 1 2002
    An Animal Model Study
    Transient increase in diastolic wall thickness (pseudohypertrophy) during pacing stress echocardiography has been reported in normal myocardium. To evaluate the occurrence of pseudohypertrophy and to investigate the contribution of myocardial ischemia on its production during pacing and dobutamine stress echocardiography, we produced a physiologically significant coronary stenosis in 14 open chest dogs. The stenosis in the circumflex artery was measured by quantitative coronary angiography (range: 50% to 89% reduction in luminal diameter), and no resting segmental wallmotion abnormalities were observed by epicardial echocardiography (short-axis, papillary level). In each study, dobutamine (5,40 ,g/kg/min) and pacing (up to 260 beats/min) were performed randomly. Positivity of stress echocardiography tests was quantitatively determined by a significant (P < 0.05) reduction or failure to increase in absolute and percent systolic wall thickening in the myocardial area supplied by the stenotic artery as compared to the left anterior descending (LAD) artery-related areas. Diastolic wall thickness and left ventricular diastolic area were compared before and after each stress test in the circumflex and LAD artery-related regions. Pseudohypertrophy was observed in 57% and 86% of dogs for pacing and dobutamine, respectively, in the circumflex region, and in 50% and 64% in the LAD region. Despite its increased incidence in the circumflex region, the augmented diastolic wall thickness did not correlate with coronary stenosis severity or stress test positivity, but correlated inversely with changes in left ventricular diastolic area. In addition, it correlated directly with changes in heart rate only for pacing. In conclusion, pseudohypertrophy was a frequent finding during pacing and dobutamine stress echocardiography tests but was not related to myocardial ischemia in this animal model. [source]


    Nuclear Cardiology in the Evaluation of Acute Chest Pain in the Emergency Department

    ECHOCARDIOGRAPHY, Issue 6 2000
    Brian G. Abbott M.D.
    Only a minority of patients presenting to the emergency department (ED) with acute chest pain will eventually be diagnosed with an acute coronary syndrome. The majority will have an electrocardiogram that is normal or nondiagnostic for acute myocardial ischemia or infarction. Typically, these patients are admitted to exclude myocardial infarction despite a very low incidence of coronary artery disease. However, missed myocardial infarctions in patients who are inadvertently sent home from the ED have significant adverse outcomes and associated legal consequences. This leads to a liberal policy to admit patients with chest pain, presenting a substantial burden in terms of cost and resources. Many centers have developed chest pain centers, using a wide range of diagnostic modalities to deal with this dilemma. We discuss the methods currently available to exclude myocardial ischemia and infarction in the ED, focusing on the use of myocardial perfusion imaging as both an adjunct and an alternative to routine testing. We review the available literature centering on the ED evaluation of acute chest pain and then propose an algorithm for the practical use of nuclear cardiology in this setting. [source]


    Plasma matrix metalloproteinase-3 level is an independent prognostic factor in stable coronary artery disease

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2005
    T. C. Wu
    Abstract Background, Recent evidence suggests the important role of matrix metalloproteinases (MMPs) in the progression of atherosclerosis and development of clinical events. We assessed the prognostic value of different plasma MMPs in patients with stable coronary artery disease (CAD). Materials and methods, A total of 165 consecutive nondiabetic patients with angiographically significant CAD (n = 150) or normal coronary angiograms despite exercise-induced myocardial ischemia (cardiac syndrome X, n = 15) and 17 normal subjects were evaluated. In each subject, plasma inflammatory markers including high sensitivity C-reactive protein (hsCRP) and MMP-2, 3 and 9 were measured. In CAD patients, major cardiovascular events including cardiac death, nonfatal myocardial infarction, unscheduled coronary revascularization and hospitalization as a result of unstable angina were prospectively followed up for more than 6 months. Results, Plasma levels of MMPs were significantly higher in CAD patients than in those with cardiac syndrome X and in normal subjects (MMP-2: 91476 1320 vs. 83079 3195 vs. 78308 2840 ng mL,1, P = 0002; MMP-3: 12959 421 vs. 11686 809 vs. 9171 955 ng mL,1, P = 0011; MMP-9: 3142 284 vs. 1140 549 vs. 671 289 ng mL,1, P = 0006). In CAD patients, there were 48 major cardiovascular events during a mean follow-up period of 1774 085 months. The numbers of diseased vessels (HR = 219, 95% CI 120,102, P = 0011), plasma hsCRP (HR = 221, 95% CI 118,411, P = 0013) and MMP-3 level (HR = 246, 95% CI = 115,528, P = 0021) were associated with the development of cardiovascular events. However, only the plasma MMP-3 level was an independent predictor of the adverse events in CAD patients (HR = 247, 95% CI 110,554, P = 0028). Conclusions, Plasma MMP levels were increased in CAD patients. Plasma MMP-3 level, rather than hsCRP, was an independent prognostic marker for future cardiovascular events, suggesting its potential role in risk stratification and clinical management of stable CAD. [source]


    Effects of percutaneous transluminal coronary angioplasty on coronary adenosine concentrations in humans

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2 2000
    Paganelli
    Background Even minimal amounts of adenosine is released during myocardial ischemia. Its role in coronary blood flow has been extensively studied, but little is known about its behaviour during percutaneous transluminal angioplasty (PTCA) in man. Material and methods Using in situ samples the aim of this study was to evaluate adenosine plasma concentration before and after PTCA. Ten patients (8 men and 2 women, mean age 65 9 years) with a single stenosis of the left anterior descending coronary artery (LAD) of at least 70% and 10 healthy volunteers (4 men and 6 women, mean age 55 9 years) were included in the study. Results and discussion We found that there is a close relationship between the degree of the stenosis and the adenosine concentrations in the great cardiac vein and in the LAD, and that after PTCA there is a drop in adenosine concentration downstream from the stenosis. This study confirms the crucial role of adenosine in coronary blood flow control. [source]


    Do Diabetic Patients Have Higher In-hospital Complication Rates When Admitted from the Emergency Department for Possible Myocardial Ischemia?

    ACADEMIC EMERGENCY MEDICINE, Issue 3 2000
    Peter B. Richman MD
    Abstract Objective: To compare in-hospital complication rates for diabetic and nondiabetic patients admitted from the emergency department (ED) for possible myocardial ischemia. Methods: This was a prospective, observational study of consecutive consenting patients presenting to a suburban university hospital ED during study hours with typical and atypical symptoms consistent with cardiac ischemia. Demographic, historical, and clinical data were recorded by trained research assistants using a standardized, closed-question, data collection instrument. Inpatient records were reviewed by trained data abstractors to ascertain hospital course and occurrence of complications. Final discharge diagnosis of acute myocardial infarction (AMI) was assigned by World Health Organization criteria. Categorical and continuous data were analyzed by chi-square and t-tests, respectively. All tests were two-tailed with alpha set at 0.05. Results: There were 1,543 patients enrolled who did not have complications at initial presentation; 283 were diabetic. The rule-in rate for AMI was 13.8% for nondiabetic patients and 17.7% for diabetic patients (p = 0.09). Times to presentation were similar for nondiabetic vs diabetic patients [248 minutes (95% CI = 231 to 266) vs 235 minutes (95% CI = 202 to 269); p = 0.32]. Nondiabetic patients tended to be younger [56.6 years (95% CI = 55.8 to 57.4) vs 61.6 years (95% CI = 60.2 to 63.1); p = 0.001] and were less likely to be female (34.3% vs 48.1%; p = 0.001). The two groups had similar prevalences for initial electrocardiograms diagnostic for AMI (5.5% vs 7.4%; p = 0.21). There was no significant difference between nondiabetic and diabetic patients for the occurrence of the following complications after admission to the hospital: congestive heart failure (1.3% vs 1.1%, p = 0.77); nonsustained ventricular tachycardia (VT) (1.3% vs 1.2%, p = 0.93); sustained VT (1.2% vs 1.1%, p = 0.85); supraventricular tachycardia (1.7% vs 3.2%, p = 0.12); bradydysrhythmias (1.9% vs 1.1%, p = 0.33); hypotension necessitating the use of pressors (0.9% vs 1.1%, p = 0.76); cardiopulmonary resuscitation (0.2% vs 0.7%, p = 0.10); and death (0.3% vs 0.7%, p = 0.34). One or more complications occurred with similar frequencies for patients in the two groups (6.3% vs 5.7%; p = 0.70). Conclusions: No statistically significant difference was found in the post-admission complication rates for initially stable diabetic vs nondiabetic patients admitted for possible myocardial ischemia. Based on these results, the presence or absence of diabetes as a comorbid condition does not indicate a need to alter admitting decisions with respect to risk for inpatient complications. [source]


    Levosimendan cardioprotection in acutely ,-1 adrenergic receptor blocked open chest pigs

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2010
    C. METZSCH
    Background: Levosimendan and volatile anesthetics have myocardial pre-conditioning effects. ,-1 adrenergic receptor antagonists may inhibit the protective effect of volatile anesthetics. No information exists as to whether this also applies to the pre-conditioning effect of levosimendan. We therefore investigated whether levosimendan added to metoprolol would demonstrate a cardioprotective effect. Methods: Three groups of anesthetized open chest pigs underwent 30 min of myocardial ischemia and 90 min of reperfusion by temporary occlusion of the largest side branch from the circumflex artery or the left anterior descending artery. One group (CTRL) served as a control, in another group (BETA), a metoprolol-loading dose was intravenously injected 30 min before ischemia, and in a third group (BETA+L), a levosimendan infusion was added to metoprolol. Myocardial tissue concentrations of glucose, glycerol, and lactate/pyruvate ratio as the primary end-points were investigated with microdialysis in ischemic and non-ischemic tissues. Results: At the end of the ischemic period, statistically significant differences were only found between CTRL and BETA+L in the ischemic myocardium, with a lower lactate/pyruvate ratio, lower glycerol, and higher glucose concentrations in BETA+L as compared with CTRL. There were no differences in non-ischemic myocardium. From 10 to 90 min of reperfusion, no more differences were found between groups. Conclusion: The cardioprotective effect of levosimendan on ischemic metabolism with a reduction in the myocardial lactate/pyruvate ratio, less glycerol accumulation, and better preserved glucose concentration does not seem to be prevented by ,-1 adrenergic receptor antagonism with metoprolol. [source]


    Surgical Treatment of Coronary Artery-Pulmonary Artery Fistula with Coronary Artery Disease

    JOURNAL OF CARDIAC SURGERY, Issue 6 2009
    Pavle Kova, Ph.D.
    Usually they are asymptomatic, but sometimes they can mimic other cardiac diseases, most commonly heart failure, myocardial ischemia, and endocarditis. Coronary arteriovenous fistulae have been reported to arise more commonly from the right coronary artery. Most of these fistulae are congenital, and only a small fraction acquired. In this report we present successful surgical treatment of coronary artery to pulmonary artery fistula combined with myocardial revascularization. [source]


    Apoptosis and Cardiopulmonary Bypass

    JOURNAL OF CARDIAC SURGERY, Issue 2 2007
    M.S., Miljenko Kova
    Apoptotic index (AI) obtained with in situ terminal deoxynucleotidyl transferase-labeled dUTP nick end labeling (TUNEL) method and Bak protein expression were compared. Patients and Methods: Twenty consecutive patients who underwent coronary artery bypass surgery, myocardial samples from the right atrium were taken in three stages: before cannulation (the first sample group), after declamping (the second sample group), and 20 minutes after reperfusion (the third sample group). The percentage of apoptotic cells was determined by TUNEL method. Expression of Bak protein was immunohistochemically analyzed. Intermittent ischemia and moderate hypothermia were used as methods of myocardial management during surgery. A statistical analysis was performed by using the Friedman ANOVA analysis of variances, the Kendall coefficient of concordance and the Wilcoxon matched pair test. Results: In the first sample group mean value of Bak expression was 2.61 2.18, compared with AI 5.38 3.58, after declamping (the second sample group) the mean value of Bak expression was 4.31 2.68 while AI was 7.63 4.38 and after 20 minutes of reperfusion in the third sample group mean value of Bak expression was 8.89 4.45, while AI was 15.6 8.45. When compared by using Wilcoxon matched pair test two methods significantly correlated, p > 0.0001. Conclusion: The positive correlation between AI obtained by TUNEL method and expression of Bak protein may suggest that apoptosis is activated mainly through mitochondrial activation pathway in ischemic reperfusion injury. The results suggest that ischemic reperfusion injury increases the AI in the right atrial tissue. If so, immunohistochemical expression of Bak protein could be used as a marker of myocardial ischemia induced injury. [source]


    Peroxidatic activity in heart effluent: a biochemical parameter for the assessment of experimental ischemia-reperfusion injury

    JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2000
    M.V. Leabu
    Abstract Peroxidatic activity in heart effluent was defined as a new biochemical parameter for the experimental study of myocardial ischemia. The peroxidatic reaction was determined by dot blot analysis with 3,3,-diaminobenzidine as hydrogen donor. After ischemia, the level of peroxidatic activity in heart effluent was 2-3 times higher than before. The effects in experimental modulation of ischemia, such as nicorandil or aprikalim protection, and the reversibility of protection by glibenclamide, could accurately be noted using the level of peroxidatic activity in heart effluent as a biochemical parameter. The results were in good agreement with those obtained for other enzymes used as biochemical parameters in experimental heart ischemia-reperfusion studies. [source]


    Prognostic value of combination of heart-type fatty acid-binding protein and ischemia-modified albumin in patients with acute coronary syndromes and normal troponin T values

    JOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 1 2009
    Cui Liyan
    Abstract Recent studies have suggested that heart-type fatty acid-binding protein (H-FABP) may detect ongoing myocardial damage involved in the progression of acute coronary syndromes (ACS). This study was prospectively designed to examine whether the combination of H-FABP, a marker for ongoing myocardial damage, and ischemia-modified albumin (IMA), a marker for myocardial ischemia, would effectively diagnose patients with ACS. H-FABP values above 1.5,g/l can be correctly measured via an ELISA and 6,g/l is the currently used cut-off value (1,3). We measured serum H-FABP and IMA of 108 patients on admission within 12,hr after onset of chestpain and normal troponin T. serum samplesfrom ACS group (n=82) had decreased capacity of ACB [64 (61,67),U/ml] compared with non-ACS ischemic chest pain group (n=26) samples [75 (71,78),U/ml] (P<0.05). The combination of IMA and H-FABP usually had better sensitivity [96.3% (92.2,100%)] (P<0.05) and accuracy [92.6 (87.7,97.5%)] (P<0.05) than when individually used. Thus, the combination of H-FABP and IMA measurements after initiation of chest pain may be highly effective for risk stratification in patients with ACS and normal cardiac troponin T. J. Clin. Lab. Anal. 23:14,18, 2009. 2009 Wiley-Liss, Inc. [source]


    An Analysis of Possible Mechanisms of Unexpected Death Occurring in Hydatid Disease (Echinococcosis)

    JOURNAL OF FORENSIC SCIENCES, Issue 4 2009
    Roger W. Byard M.B.B.S.
    Abstract:, Most cases of hydatid disease in human populations are due to Echinococcus granulosus. The hydatid life cycle involves passage between definitive hosts such as dogs and intermediate hosts such as sheep. Humans become accidental intermediate hosts following ingestion of food or water contaminated with eggs or by contact with infected dogs. Although hydatid disease may remain asymptomatic, occasional cases of sudden and unexpected death present to autopsy. Causes of rapid clinical decline involve a wide range of mechanisms including anaphylaxis (with or without cyst rupture), cardiac outflow obstruction or conduction tract disturbance, pulmonary and cerebral embolism, pericarditis, cardiac tamponade, myocardial ischemia, pulmonary hypertension, peritonitis, hollow organ perforation, intracerebral mass effect, obstructive hydrocephalus, seizures, cerebral ischemia/infarction, and pregnancy complications. The autopsy assessment of cases therefore requires careful examination of all organ systems for characteristic cystic lesions, as multiorgan involvement is common, with integration of findings so that possible mechanisms of death can be determined. Measurement of serum tryptase and specific IgE levels should be undertaken for possible anaphylaxis. [source]


    Successful Double Percutaneous Alcohol and Coil Embolization of Bilateral Coronary-to-Pulmonary Artery Fistulas

    JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2000
    GIUSEPPE SANGIORGI M.D.
    We report the case of a 70-year-old man with recent myocardial infarction who was admitted for further evaluation of his effort angina. Cardiac catheterization and selective coronary angiography excluded significant coronary atherosclerotic disease of the coronary arteries. Double coronary-to-pulmonary artery fistulas, one originating from the proximal right, the other from the left anterior descending coronary arteries, and draining into the right and left branch of the pulmonary artery, respectively, were observed. A left-to-right shunt was visualized at angiography. The patient was successfully treated with percutaneous alcohol and coil embolization of both coronary artery fistulas with total resolution of clinical symptoms. At 6-month follow-up a coronary angiography confirmed complete disappearance of the fistulas. We conclude that a "coronary steal" phenomenon caused by the fistulas induced myocardial ischemia in this patient and that percutaneous transcatheter exclusion with chemical and mechanical devices is a safe. effective, and reasonable alternative to traditional cardiac surgery. [source]


    Magnetic resonance imaging for ischemic heart disease

    JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2007
    Hajime Sakuma MD
    Abstract Cardiac MRI has long been recognized as an accurate and reliable means of evaluating cardiac anatomy and ventricular function. Considerable progress has been made in the field of cardiac MRI, and cardiac MRI can provide accurate evaluation of myocardial ischemia and infarction (MI). Late gadolinium (Gd)-enhanced MRI can clearly delineate subendocardial infarction, and the assessment of transmural extent of infarction on late enhanced MRI has been shown to be useful in predicting functional recovery of dysfunctional myocardium in patients after MI. Stress first-pass contrast-enhanced (CE) myocardial perfusion MRI can be used to detect subendocardial ischemia, and recent studies have demonstrated the high diagnostic accuracy of stress myocardial perfusion MRI for detecting significant coronary artery disease (CAD). Free-breathing, whole-heart coronary MR angiography (MRA) was recently introduced as a method that can provide visualization of all three major coronary arteries within a single three-dimensional (3D) acquisition. With further improvements in MRI techniques and the establishment of a standardized study protocol, cardiac MRI will play a pivotal role in managing patients with ischemic heart disease. J. Magn. Reson. Imaging 2007;26:3,13. 2007 Wiley-Liss, Inc. [source]


    Clinical Assessment of Ischemia-modified Albumin and Heart Fatty Acid,binding Protein in the Early Diagnosis of Non-ST-elevation Acute Coronary Syndrome in the Emergency Department

    ACADEMIC EMERGENCY MEDICINE, Issue 1 2010
    Sandrine Charpentier MD
    Abstract Objectives:, Heart fatty acid,binding protein (h-FABP) and ischemia-modified albumin (IMA) have recently been evaluated, but to the best of our knowledge, no study has reported an analysis of these two markers for the detection of early myocardial infarction and myocardial ischemia in a large cohort of consecutive patients presenting to an emergency department (ED). This study evaluates the diagnostic accuracy and the clinical utility of h-FABP and IMA for non-ST-segment elevation acute coronary syndrome (ACS) diagnosis in the first hour of management in an ED. Methods:, In a prospective 11-month study, 677 patients admitted to the ED with chest pain and suspected non-ST-segment elevation ACS were enrolled. On presentation, blood samples were obtained for the measurement of the biomarkers h-FABP (immunodetection with CardioDetect) and IMA (albumin cobalt-binding test). Two physicians, blinded to the results of the markers, independently categorized patients as having or not having non-ST-segment elevation ACS. Results:, Of the 677 patients who were prospectively recruited, non-ST-segment elevation ACS was diagnosed in 185 (27.3%). While IMA was not predictive of the ACS diagnosis (odds ratio [OR] = 1.23; 95% CI = 0.87 to 1.81), h-FABP was predictive of ACS diagnosis (OR = 4.65; 95% CI = 2.39 to 9.04) with specificity at 96.8% (95% CI = 95.4% to 98.1%) and sensitivity at 13.5% (95% CI = 10.9% to 16.1%). However, h-FABP did not add significant additional information to a predictive model that included the usual diagnostic tools for non-ST-elevation ACS management (p = 0.40). Conclusions:, In this study on a large cohort of patients admitted to an ED for chest pain, IMA and h-FABP did not provide valuable information for ACS diagnosis. ACADEMIC EMERGENCY MEDICINE 2010; 17:27,35 2010 by the Society for Academic Emergency Medicine [source]


    Thrombin generation during reperfusion after coronary artery bypass surgery associates with postoperative myocardial damage

    JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2006
    P. RAIVIO
    Summary.,Background: Cardiopulmonary bypass and coronary artery bypass grafting (CABG) result in significant thrombin generation and activation of fibrinolysis. Thrombin contributes to myocardial ischemia,reperfusion injury in animal studies, but the role of thrombin in myocardial damage after CABG is unknown. Objectives: We measured thrombin generation and fibrin turnover during reperfusion after CABG to evaluate their associations with postoperative hemodynamic changes and myocardial damage. Methods: One hundred patients undergoing primary, elective, on-pump CABG were prospectively enrolled. Plasma prothrombin fragment F1+2 and D-dimer were measured preoperatively and at seven time points thereafter. Mass of the Mb fraction of creatine kinase (Ck-Mbm) and troponin T (TnT) were measured on the first postoperative day. Results: Reperfusion induced an escalation of thrombin generation and fibrin turnover despite full heparinization. F1+2 during early reperfusion associated with postoperative pulmonary vascular resistance index. F1+2 at 6 h after protamine administration correlated with Ck-Mbm (r = 0.40, P < 0.001) and TnT (r = 0.44, P < 0.001) at 18 h postoperatively. Patients with evidence of myocardial damage (highest quintiles of plasma Ck-Mbm and TnT) had significantly higher F1+2 during reperfusion than others (P < 0.002). Logistic regression models identified F1+2 during reperfusion to independently associate with postoperative myocardial damage (odds ratios 2.5,4.4, 95% confidence intervals 1.04,15.7). Conclusions: Reperfusion caused a burst in thrombin generation and fibrin turnover despite generous heparinization. Thrombin generation during reperfusion after CABG associated with pulmonary vascular resistance and postoperative myocardial damage. [source]