Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The myocardial contractility function was studied with the aid of echocardiography in 42 male patients during dosaged physical exercises. The patients were selected so that at the peak of the exercises they developed an angina pectoris attack documented by ischaemic ECG changes. In some of the patients the changes were also observed during attacks of angina decubitus. Anginal attacks are accompanied by a reduction of the myocardial function. Haemodynamic reactions of two types were noted with myocardial ischaemia: type I reaction was observed in patients with ischaemic heart disease and practically normal values of the initial heart volume, and consisted in an increasing end-systolic and end-diastolic volumes, with the stroke volume remaining unchanged, and the ejection fraction somewhat decreasing; type 2 reaction was observed in patients with initially increased heart volumes, and consisted in a decreasing end-diastolic and stroke volumes, with an insignificant alteration of the end-systolic volume. The ejection fraction, being initially insignificantly decreased, tends to decrease further during the attack.
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PMID:[Myocardial contractility during angina pectoris attack in ischemic heart disease]. 85 2

Twenty-one patients with angiographic evidence of significant coronary artery disease, and positive dipyridamole echocardiographic test results at basal condition and after 7 days of placebo treatment were prospectively studied to see whether beta blockade modifies the effects of dipyridamole echocardiographic testing on regional myocardial contractility. Patients were randomized to propranolol (120 mg/day) or placebo treatment in 3 divided doses for 7 days, after which each patient crossed over to the alternate regimen. Dipyridamole-echocardiographic testing was repeated at the end of each treatment. Propranolol abolished new mechanical signs of transient dipyridamole-induced ischemia (new wall motion abnormalities or an increase in degree of basal asynergies, or both) in 13 of 21 patients. The remaining 8 patients had positive results on dipyridamole echocardiographic testing after the propranolol treatment period. At basal conditions both heart rate and rate-pressure product were significantly reduced with propranolol; there was also a significant decrease in these parameters at peak dipyridamole infusion. At peak dipyridamole infusion heart rate and rate-pressure product were significantly lower in patients with negative than in those with positive echocardiographic test results after propranolol. Our data show that administration of beta blockade significantly reduces the development of transient dipyridamole-induced myocardial asynergies, the earliest markers of acute myocardial ischemia, detected with 2-dimensional echocardiography.
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PMID:Effect of beta-adrenoceptor blockade on dipyridamole-induced myocardial asynergies in coronary artery disease. 135 29

To determine the utility for detecting ischemic heart disease (IHD), Dipyridamole thallium myocardial images (DIP-Tl) have been performed in the 103 patients with atherosclerotic vascular disease who can't exercise fully. Of 103 patients, there were 36 patients with arteriosclerosis obliterans (ASO), 31 patients with aneurysm of the abdominal aorta (AAA), 24 patients with aneurysm of the thoracic aorta (TAA) and 12 patients with dissecting aortic aneurysm (DAA). Clinical evidence of IHD was found in 20 patients with ASO, 10 with AAA, 7 with TAA and 4 with DAA respectively. Positive evidence of DIP-Tl was identified in 66% of 41 patients who had clinical evidence of IHD, and particularly in the patients with AAA (80%) and ASO (65%). On the other hand, in the patients without clinical evidence of IHD, positive evidence of DIP-Tl was identified in 19% of 62 patients and particularly in the patients with AAA (39%). In all patients, the percentage of the positive DIP-Tl ratio was 38%. And, when the 38% patients of the positive DIP-Tl were added to the patients of the negative DIP-Tl who had clinical evidence of IHD, almost half patients (51%) were considered to be complicated with IHD. This study suggests that the atherosclerotic vascular disease is highly complicated with IHD and DIP-Tl is useful to detect IHD.
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PMID:[Usefulness of 201Tl myocardial scintigraphy after dipyridamole infusion in patients with atherosclerotic vascular disease]. 158 8

The clinical usefulness of cardiac imaging modalities that rely upon the detection of perfusion defects and wall motion disturbances requires conditions that provoke a heterogeneity of coronary flow and a myocardial oxygen imbalance, respectively. Traditionally, this has been achieved by exercise stress testing. Many patients cannot perform dynamic exercise sufficiently for various reasons. Pharmacologic stress has been proven to be an attractive alternative for physical exercise. Currently, several stressing agents are used in conjunction with thallium-201 scintigraphy, 2-D echocardiography and, recently, MRI. The most employed agents include vasodilators, such as dipyridamole and adenosine, and catecholamines, such as dobutamine (Table VI). The predominant rationale of thallium-201 perfusion scintigraphy is based on the creation of a flow maldistribution between territories supplied by normal arteries and those supplied by stenotic arteries that does not necessarily require ischemia. Dipyridamole and adenosine, as rather selective coronary vasodilators, are well suited to provoke such a condition and may be classified as the ideal markers of myocardial perfusion. 2-D echocardiography and MRI have the potential to provide noninvasively derived information of cardiac dynamics and regional myocardial function. To assess the functional significance of coronary artery disease, detection of wall motion abnormalities and alterations in ejection fraction require the presence of myocardial ischemia. Dobutamine, as a widely applied inotropic agent in the management of severely depressed left ventricular contractile function, seems to be an appropriate pharmacologic stressor when heart failure is absent. By increasing contractility, heart rate, and systolic arterial pressure, it is capable of inducing an imbalance between myocardial oxygen demand and supply, leading to ischemia in patients with coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:New developments in pharmacologic stress imaging. 163 90

Cardiac imaging with dipyridamole infusion has been proposed as an exercise-independent tool for the diagnosis of coronary artery disease. Dipyridamole acts through the accumulation of adenosine, which reduces sympathetic tone in vasomotor nuclei of the brainstem and inhibits norepinephrine release in noradrenergic neurons but also activates arterial chemoreceptors. The aim of this study was to assess whether dipyridamole administration (up to 0.84 mg/kg over 10 minutes, a dosage commonly employed for diagnostic testing) may modulate sympathetic activity either directly or indirectly through blood pressure reduction or myocardial ischemia, which may be evoked by dipyridamole infusion and represent two recognized sympathetic stimuli. Twenty patients were studied with infusion combined with two-dimensional echocardiography and 12-lead ECG monitoring. Blood pressure was recorded each minute by a cuff sphygmomanometer. In all patients, we obtained venous blood samples for epinephrine (an index of adrenomedullary catecholamine release) and norepinephrine (an index of neuronal activity) both in resting conditions and at peak dipyridamole, ie, at the first minute after termination of dipyridamole infusion in negative cases or in the presence of obvious ischemia in positive cases (ie, as soon as a regional ventricular dyssynergy or an ST segment depression greater than 0.1 mV appeared). Epinephrine and norepinephrine determinations were made by a high performance liquid chromatography (HPLC) method. After dipyridamole, there was a significant rise in norepinephrine, while epinephrine did not change significantly. Dipyridamole-induced percentage variations of norepinephrine from baseline were not significantly correlated with mean blood pressure changes (r = .1, p = ns) and were of a similar extent in patients with (n = 10) and without (n = 10) dipyridamole-induced ischemia (+68 vs +73 percent, p = ns). Dipyridamole administration provokes an activation of sympathetic tone which can be detected even in the absence of myocardial ischemia and is not related to blood pressure changes. The increased catecholamine release appears to be of neuronal rather than adrenomedullary origin.
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PMID:Activation of sympathetic tone during dipyridamole test. 164 30

Doppler assessment of left ventricular filling and ejection during dipyridamole stress may supplement wall motion analysis for detection of myocardial ischemia and coronary artery disease (CAD). Thirty-four patients taking no cardioactive therapy were studied using intravenous dipyridamole (0.6 mg/kg) during 2-dimensional and pulsed Doppler echocardiography. Twelve patients had normal coronary arteries (group 1) and the remainder, who had significant CAD, were divided into groups 2 (n = 11) and 3 (n = 11). Only subjects in group 2 developed myocardial ischemia manifest as reversible regional asynergy and ST-segment depression. Heart rate increased (16 +/- 9 beats/min, p less than 0.01) and mean blood pressure decreased (-5 +/- 8 mm Hg, p = not significant) uniformly across groups. Exaggerated hyperkinesia of normally contracting wall segments was the common response to dipyridamole infusion in patients with CAD. The respective mean percent changes in peak early diastolic velocity, peak atrial velocity, their ratio and ejection peak velocity, and mean acceleration for groups 1 (20, 42, -13, 20 and 23%), 2 (22, 32, -2, 10 and 14%) and 3 (23, 33, -6, 16 and 18%) were similar. Comparisons between normal patients and those with CAD and between groups 2 and 3 revealed no significant differences in the effect of dipyridamole on any variable. However, a decrease in both peak velocity and mean acceleration of left ventricular ejection was seen in 3 of 4 group 2 patients who developed severe ischemia. Dipyridamole-Doppler echocardiography is insensitive for detection of CAD and appears unable to identify myocardial ischemia unless this is severe. Hemodynamic changes and compensatory wall motion induced by dipyridamole may explain these findings.
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PMID:Evaluation of dipyridamole-Doppler echocardiography for detection of myocardial ischemia and coronary artery disease. 187 75

A case of severe myocardial ischaemia complicated by syncopal ventricular tachycardia during injection of Dipyridamole for stress Thallium myocardial scintigraphy in a coronary patient is reported. Myocardial ischaemia (chest pain, ECG changes) is classically rare (30% of cases) and usually benign during Dipyridamole injection, and either regress spontaneously or after administration of Theophylline. However, the possibility of serious complications such as this justifies the same criteria of strict surveillance as for classical exercise stress testing.
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PMID:[Severe ischemic ventricular arrhythmia during dipyridamole scintigraphy]. 189 21

This article deals with the application of pharmacological stress echocardiography, a relatively new and evolving technique, to the diagnosis and assessment of patients with coronary artery disease. The value of echocardiography in ischaemic heart disease is initially outlined, followed by a brief review of the exercise two-dimensional echocardiography and exercise echo-Doppler literature. Dipyridamole, adenosine and dobutamine stress echocardiography are then examined, and the rationale and potential advantages of this approach explained. The findings of our own work using dipyridamole and dobutamine stress, combined with both two-dimensional echocardiography and Doppler, are then described. A review of the various methods of echocardiographic image analysis is then presented and the article concludes by suggesting directions for future work.
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PMID:Pharmacological stress echocardiography in the evaluation of coronary artery disease. 192 76

Pharmacologic stress imaging has increasingly been employed as an alternative to exercise imaging for detection of coronary artery disease and risk stratification particularly in patients who are unable to perform adequate exercise. Sensitivity and specificity of thallium 201 scintigraphy using intravenous dipyridamole infusion as a stress for coronary artery disease detection average 85% and 91%, respectively. Dipyridamole imaging is also useful for differentiating between ischemia and scar and identifying patients who have an increased risk for subsequent cardiac events. Dipyridamole imaging is particularly useful for preoperative risk stratification in patients undergoing surgery for peripheral vascular or aortic disease. Dipyridamole imaging is also useful for identifying residual myocardial ischemia after myocardial infarction and detecting restenosis after coronary angioplasty. Adverse side effects of dipyridamole are promptly reversed by aminophylline. Dipyridamole stress can also be employed in association with echocardiography for detection of ischemia-induced regional wall motion abnormalities.
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PMID:Pharmacologic stress imaging. 198 15

Dipyridamole cardiac imaging is a useful alternative to exercise stress testing in the evaluation of patients with ischemic heart disease. Intravenous dipyridamole has been approved recently for clinical use. Oral dipyridamole is widely available. The hemodynamic effects of dipyridamole include an increase in coronary blood flow in excess of the increase in myocardial oxygen consumption and cardiac output. The quality of the thallium images is better or similar to that of exercise thallium images. The optimal dose of intravenous dipyridamole is 0.56 mg/kg and the optimal oral dose is 300-375 mg, although higher doses may be necessary in some patients. The sensitivity and specificity of dipyridamole-thallium imaging, whether intravenous or oral, have been shown in a number of studies to be quite adequate and comparable to that achieved during exercise thallium imaging. Dipyridamole-thallium imaging has also been useful in identifying high-risk patients undergoing major elective vascular surgery. The relative merits of dipyridamole imaging versus exercise testing after acute myocardial infarction require further studies.
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PMID:Dipyridamole thallium imaging. 203 31


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