Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.1.1.6 (CAD)
 4,420 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ventricular late potentials (LP) seem to reflect mixed, anatomic and electrophysiologic substrate for ventricular reentrant tachyarrhythmias. Ischemic events can perform areas of delay and dispersion of conduction and refractoriness in patients with ischaemic heart disease (CAD), especially after myocardial infarction (MI). These electrophysiological disturbances can induce the reentry phenomenon. LP are present in 18-53% patients with CAD, but in selected groups of patients after MI with ventricular tachycardia or/and cardiac arrest in the past, LP are registered in 63-92% objects. The influence of acute ischemia provoked by the effort and pharmacological stress testing isn't significant in groups with CAD without MI. Occurrence of LP increase in a small grade only in post-MI patients but differences of time domain parameters of signal-averaged ECG (SAECG) are not statistically significant. There are no correlations between LP incidence during ischemia and left ventricle wall motion disturbances, ejection fraction, localisation of MI, date of MI and number of occluded coronary vessels in the greater part of investigations, but the results are divergent and the matter has to be studied. Time domain SAECG is one of admitted methods of risk stratification of incidence of sustained ventricular tachycardia in patients with CAD, but the parameters of frequency domain SAECG still are not standardized, so its clinical usefulness isn't clear.
 ...
PMID:[The influence of myocardial ischemia on the electrocardiogram under stress]. 946 14

Preventing the progression of established heart failure can be difficult, as multiple factors contribute to the continual decline of cardiac function. Blunting the activated neurohormonal response to a decreased systolic function is a proven means of slowing progression of CHF. Preventing further CAD and cardiac ischemia may also prove to be an effective mechanism. Two trials with HMGCoA reductase inhibitors lend support to this hypothesis. Studies using ACE inhibitors may also support this notion. Since a major portion of heart failure in the USA is caused by CAD, preventing CHF progression may be related to the prevention of CAD. Using ACE inhibitors and lipid-lowering agents, in addition to standard measures of CAD risk factor modification, may prove useful in future trials to retard the progression of heart failure. Further research and clinical trials involving this method of CHF prevention are warranted.
 ...
PMID:Role of secondary prevention in congestive heart failure due to coronary artery disease. 989 17

The ECG stress test represents the most commonly-used technique to evaluate the occurrence of nitroglycerin tolerance. It acts by increasing cardiac O2 demand with resulting insufficient blood flow through a stenotic coronary artery and development of cardiac ischemia. However, other tests are also potentially suitable, such as the ECG-dipyridamole test. The aim of the present study was to evaluate the acute response of ECG-dipyridamole and ECG-stress tests to nitroglycerin. In particular, the development of nitroglycerin tolerance during chronic therapy was evaluated with both tests in patients with stable angina. Eleven patients (8 men and 3 women) with CAD proven by a previous coronarography, a known history of stable angina within at least six months and a positive response to both the tests were studied. At the end of a seven-day wash-out period, all patients were positive to initial ECG-stress and ECG-dipyridamole tests; after 3 days a new evaluation was carried out (Effort 0 and Dip 0) and this confirmed the previous results. We performed a randomized trial in two phases: acute and chronic therapy. In the acute phase, all patients underwent ECG-stress and ECG-dipyridamole tests (Effort 1 and Dip 1) in a randomized fashion one day apart, four hours after administration of a 10 mg/24 h nitroglycerin patch. The chronic phase consisted of 25 days of continuous treatment with a nitroglycerin patch. The two tests (Effort 2 and Dip 2) were always repeated after four hours of the morning therapy. Nitroglycerin does not modify the hemodynamic response to dipirydamole in either acute or chronic treatment. Lastly, our data confirm the efficacy of nitroglycerin on stress and dipyridamole tests after acute administration. Nitroglycerin tolerance is confirmed by both tests although with different patterns. ECG stress test showed nitroglycerin tolerance because time to ischemia and max ST deteriorated during chronic therapy. Moreover, the ECG-dipyridamole test showed nitroglycerin tolerance because five patients with a negative acute test (Dip 1) became positive during chronic therapy (Dip 2).
 ...
PMID:[Therapy with nitro derivatives and the development of tolerance: a comparative study with stress ECG and dipyridamole ECG]. 1036 22

In this article we have outlined the current rationale and role of invasive management in ACS. For the majority of patients with ACS, who are either at high risk or unstable, invasive management is a critical element in breaking the sequence of recurrent ischemia leading to early cardiac events (Fig. 11). Secular trends in the care of cardiovascular patients predict even more sophisticated, invasive methods of treating coronary occlusion in the future. A futurist's view on this subject may envision the following type of scenario. A patient with prior CAD experiences persistent chest pain and notifies the emergency medical system. The paramedics arrive, and perform a rapid fingerstick cardiac biomarker panel and ECG. The results are interpreted by an emergency physician via a telecommunication system, and the patient is determined to be at high risk. He or she is triaged to a center capable of angioplasty and bypass surgery. On the way to the hospital, the patient is treated with aspirin, IV heparin, and an IV glycoprotein IIb/IIIa inhibitor. The patient undergoes triage angiography within 1 hour of hospital arrival, culprit lesion(s) are identified, and a revascularization plan is made--setting a critical pathway that is definitive. This vision is not far off on the horizon. We anticipate additional clinical trial results will help form the decision points in this optimal treatment scenario, which for a large proportion of patients will involve invasive management.
 ...
PMID:Early use of coronary angiography and intervention. 1038 33

Myocardial ischemia is common during ICUS imaging in women with and without CAD. Although no long-term adverse effects occurred in our small sample, a larger sample of women is required to confirm our observations and to determine the precise mechanisms of ischemia. Such studies may determine whether the smaller diameter of coronary vessels in women makes the women more vulnerable than men to the occurrence of chest pain and ischemia during ICUS. Although ICUS is valuable in guiding coronary interventions, disposable catheters are costly. Studies are required to assess the cost-benefit ratio of incorporating ICUS with coronary interventional procedures. Until more is known, we recommend that nurses educate patients about ICUS, monitor them closely for ischemia and arrhythmias during the procedure, and consider obtaining 12-lead ECGs when patients undergo and ICUS procedure.
 ...
PMID:Frequency of ischemia during intracoronary ultrasound in women with and without coronary artery disease. 1080 12

Sudden cardiac death occurs most frequently in persons age 50 to 60, and serious ventricular arrhythmias are the cause of death in most cases. The underlying substrate is usually CAD, either a healed infarction or an acute ischemic event. Early studies using antiarrhythmic drugs to improve post-MI survival led instead to increased mortality, casting doubt on this approach. A cascade of studies using newer antiarrhythmic drugs showed some promise in selected patients post MI. Another approach--using implantable defibrillators--may show greater benefit than antiarrhythmic drugs in patients at serious risk, but the widespread implantation of these devices may be cost-prohibitive. Management of serious ventricular arrhythmias is guided by the individual patient's comorbidities, cardiac function, history of ischemia, and perceived risk of sudden death.
 ...
PMID:Ventricular arrhythmias. Preventing sudden death with drugs and ICD devices. 1095 84

The term myocardial ischemia describes a condition which exists when fractional uptake of oxygen in the heart is not sufficient to maintain the rate of cellular oxidation. This leads to extremely complex situations which have extensively in recent years. A large amount of experimental research has been directed to establish the precise sequence of biochemical events leading to myocyte necrosis as such knowledge could lead to rational treatments designed to delay myocardial cell death. At the present time there is no simple answer to the question of what determines cell death and no recovery on reperfusion. Problems arise because: 1) ischemic-damage is not homogeneous and many factors may combine to cause cell death; 2) severity of biochemical changes and development of necrosis are usually associated (both the processes being dependent on the duration of ischemia) and it is impossible to establish a causal relationship; 3) the inevitability of necrosis can only be assessed by reperfusion of the ischaemic myocardium. Restoration of flow, however, might result in numerous further negative consequences, thus directly influencing the degree of recovery. From the clinical point of view, we have recently learnt that there are several potential manifestations and outcomes associated with myocardial ischaemia and reperfusion. Without doubt ventricular dysfunction (either systolic or diastolic) of the ischaemic zone is the most reliable clinical sign of ischemia, since ECG changes and symptoms are often absent. The ischaemia-induced ventricular dysfunction, at least initially, is reversible, as early reperfusion of the myocardium results in restoration of normal metabolism and contraction. In the ischaemic zone, recovery of contraction might occur instantaneously or, more frequently, with a considerable delay, thus yielding the condition recently recognised as the stunned myocardium. On the other hand, when ischemia is severe and prolonged, cell death might occur. Reperfusion at this stage is associated with the released of intracellular enzymes, disruption of cell membranes, influx of calcium, persistent reduction of contractility, and eventual necrosis of at least a portion of the tissue. This entity has been called reperfusion damage by those who believe that much of the injury is the consequence of events occurring at the moment of reperfusion rather than a result of changes occurring during the period of ischaemia. The existence of reperfusion damage, however, it has been questioned, and has been argued that, with the exception of induction of arrhythmias, it is difficult to be certain that reperfusion causes further injury. The existence of such an entity has clinical relevance, as it would imply the possibility of improving recovery with specific interventions applied at the time of reperfusion. In 1985 Rahimtoola described another possible out-come of myocardial ischemia. He demonstrated that late reperfusion (after months or even years) of an ischaemic area showing ventricular wall-motion abnormalities might restore normal metabolism and function. He was the first to introduce the term hibernating myocardium, referring to ischemic myocardium in which the myocytes remain viable but in which contraction is chronically depressed. Our data on metabolic changes occurring during ischemia followed by reperfusion which were obtained either in the isolated and perfused rabbit hearts or in CAD patient undergoing intracoronary thrombolysis or aortocoronary bypass grafting will be reviewed.
 ...
PMID:Ischaemic heart disease: clinical improvement with metabolic approach. 1120 4

There are no perfect tests or algorithms to exclude ACI. Because acute coronary occlusion often occurs in patients with low-grade coronary stenosis, the diagnostic goal of a chest pain diagnostic protocol is not to identify patients with CAD, but rather to identify patients who may be safely discharged home without the development of complications such as MI, unstable angina, death, shock, or CHF over the next 1 to 6 months. There is an advantage to evaluating patients at the time of their symptoms. Patients who have a small plaque that is ruptured, leading to intracoronary thrombosis and ischemia, will manifest ischemia on diagnostic testing that could missed in routine outpatient testing when their plaque were stable. The diagnosis and risk stratification of acute coronary ischemia in the ED depends on a careful history and interpretation of the ECG. Multiple regression models using readily available data (e.g., history, physical examination, and ECG) provide the best tools for risk stratification. If one is deciding how to select patients for an EDOU chest pain evaluation, diagnostic tools that have previously been tested and validated in this setting are preferable. These include the Multicenter Chest Pain Study derived tools (i.e., Goldman, Lee), the ACI and ACI-TIPI tools, and sestamibi risk stratification tools. This is not to say that other tools may not play a role at individual institutions. It is probably better to select a consistent approach and evaluate its performance, rather than to allow random variation to dictate practice. The future direction probably will involve standardization of the ED chest pain population. This allows outcome and cost-effectiveness comparative research of various strategies for patients with normal or nondiagnostic ECGs and normal biomarkers. Although this approach allows more precise stratification, the risk will never be zero, meaning that there will never be a substitute for good clinical judgment and close follow-up care.
 ...
PMID:Identification of chest pain patients appropriate for an emergency department observation unit. 1121 3

As rates of diabetes mellitus and obesity continue to increase, physical activity continues to be a fundamental form of therapy. Exercise influences several aspects of diabetes, including blood glucose concentrations, insulin action and cardiovascular risk factors. Blood glucose concentrations reflect the balance between skeletal muscle uptake and ambient concentrations of both insulin and counterinsulin hormones. Difficulties in predicting the relative impact of these factors can result in either hypoglycemia or hyperglycemia. Despite the variable impact of exercise on blood glucose, exercise consistently improves insulin action and several cardiovascular risk factors. Beyond the acute impact of physical activity, long-term exercise behaviors have been repeatedly associated with decreased rates of type 2 diabetes. While exercise produces many benefits, it is not without risks for patients with diabetes mellitus. In addition to hyperglycemia, from increased hepatic glucose production, insufficient insulin levels can foster ketogenesis from excess concentrations of fatty acids. At the opposite end of the glucose spectrum, hypoglycemia can result from excess glucose uptake due to either increased insulin concentrations, enhanced insulin action or impaired carbohydrate absorption. To decrease the risk for hypoglycemia, insulin doses should be reduced prior to exercise, although some insulin is typically still needed. Although precise risks of exercise on existing diabetic complications have not been well studied, it seems prudent to consider the potential to worsen nephropathy or retinopathy, or to precipitate musculoskeletal injuries. There is more substantive evidence that autonomic neuropathy may predispose patients to arrhythmias. Of clear concern, increased physical activity can precipitate a cardiac event in those with underlying CAD. Recognizing these risks can prompt actions to minimize their impact. Positive actions that are part of exercise programs for diabetic patients emphasize SMBG, foot care and cardiovascular functional assessment. SMBG provides critical information on the impact of exercise and is recommended for all patients before, during and after exercise. More frequent monitoring (and for longer periods following exercise) is recommended for those with hypoglycemia unawareness or those performing high-intensity exercise. Preventing the sequelae of an exercise-induced severe hypoglycemic reaction can be as simple as carrying glucose tablets or gel, a diabetic identification bracelet or card, or exercising with an individual who is aware of the circumstances. In addition to blood glucose concentrations, proper foot care is critical to people with diabetes who exercise and includes considering type of shoe, type of exercise, inspection of skin surfaces and appropriate evaluation and treatment of lesions (calluses and others). Those with severe neuropathy can consider alternatives to weight-bearing exercises. Precipitation of clinical CAD is of great concern for all diabetic patients participating in exercise activities. Although a sufficiently sensitive and specific screening test for coronary disease has not been identified, those planning an exercise program of moderate intensity or greater should be evaluated. Initial cardiac assessment should include exercise testing as well as identifying risk for autonomic neuropathy. In addition to noting maximal heart rate and blood pressure as well as ischemic changes, exercise tolerance testing can identify anginal thresholds and patients with asymptomatic ischemia. Those without symptoms should be counseled regarding target pulse rates to avoid inducing ischemia. Ischemic changes need to be evaluated for either further diagnostic testing or pharmacological intervention. For patients with diabetes mellitus, the overall benefits of exercise are clearly significant. Clinicians and patients must work together to maximize these benefits while minimizing risks for negative consequences. Identifying and preventing potential problems beforehand can reduce adverse outcomes and promote this important approach to healthy living.
 ...
PMID:Exercise and diabetes. 1157 Jan 19

Given the constant flux in caseload and the number of personnel available in the OR, waiting for a final XM often prolongs organ preservation time (a room available at the time a XM is started is not available when the XM is completed). Longer preservation is associated with increased DGF and decreased graft survival. We have shown in a retrospective analysis that final XMs on 0% PRA recipients were always negative (Transplantation, 1999). We now describe a policy of: a) not doing screening XM and b) proceeding to the OR without a XM, in situations where the recipients's PRA has been documented to be 0% and when there have not been any interim transfusions (and the OR is ready before XM completion). Final XM is completed after the transplant. All patients send sera every 6 weeks for PRA (antiglobulin technique). If > o r=3 consecutive PRAs are 0%, no donor-specific screening XM is done prior to calling the patient in for tx (UNOS allocation algorithm used). If there have not been any interim transfusions, we have proceeded to tx prior to completion of the final XM. Between 1/1/98-12/31/99, we did 109 CAD kidney (K) and 79 simultaneous kidney pancreas (SPK) tx; 67 (61%) K and 56 (71%) SPK had 0% PRA. Of the 0% PRA, 25/67 (37%) K and 28/56 (50%) SPK had no pre-tx XM. For K with no XM, cold ischemia was shorter (13.2+/-0.2 vs. 18+/-0.9 hrs, p=0.01) and DGF less (12% vs. 24%, p=0.3); for SPK with no XM, cold ischemia was shorter (15.2+/-2 vs. 18+/-0.9 hrs, p=0.1); no diff in DGF. All post-XM were negative and there were no hyperacute rejections; there was no diff in acute rejection episodes. Actuarial 1 yr graft survival: no XM-K=87.5%, SKP=82%; Yes XM-K=88%, SKP=86% (NS). Our data suggests it is safe, in select circumstances, to proceed to the OR without a XM. Elimination of the screening XM for 0% PRA candidates saves money. Proceeding of the OR (if available) without a final XM shortens cold ischemia time.
 ...
PMID:Kidney and pancreas transplantation without a crossmatch in select circumstances--it can be done. 1168 16


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>