Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two cases of subclavian steal syndrome are reported. Symptoms included light-headedness or syncope, reflecting vertebrobasilar insufficiency, and in one case, numbness and tingling in the left upper extremity, reflecting ischemia. Many persons with this syndrome are asymptomatic. Key findings include unilaterally decreased pulses and a significant difference in blood pressure between the upper extremities. Arch aortography, the "gold standard" of diagnosis, must be performed before surgical intervention.
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PMID:Subclavian steal syndrome. A report of two cases. 334 Jun 10

Myocardial ischemia, particularly when transmural as in variant angina pectoris, may be associated with ventricular tachycardia, ventricular fibrillation and paroxysmal atrioventricular block (15%). Syncope (7%) and sudden death (3%) due to these malignant arrhythmias are sometimes a unique marker of myocardial ischemia. Two-hundred fifty-four patients (220 males and 34 females), aged 5 +/- 9 years with transmural myocardial ischemia related to coronary artery spasm, were studied. Particular attention was paid to the role of syncopal attacks as unique clinical manifestation of silent ischemia. Patients examined were divided into 3 Groups. Group 1 includes 5/254 (2%) patients with atrial fibrillation during acute ischemia. Group 2 was divided into four subgroups: subgroup A includes 17/254 (7%) patients with syncopal attacks due to malignant arrhythmias (ventricular tachycardia and advanced A-V block); subgroup B, 15/254 (6%) patients with documented malignant arrhythmias, without syncopal attacks; subgroup C, 7/254 (3%) with ventricular fibrillation during acute ischemia and subgroup D, 18/254 (7%) patients with history of syncopal attacks without documented arrhythmias during hospital observation. Group 3 includes 17/254 (7%) patients with left anterior hemiblock in basal condition, 7/254 (3%) patients with left anterior hemiblock and one left posterior hemiblock during acute ischemia and one patient with right bundle branch block during acute ischemia. Syncopal symptoms are present in many of these cases of angina pectoris; paroxysmal A-V block is documented in nearly half of the cases with syncope (65%); ventricular tachycardia is frequently demonstrated during ischemia but leads to syncope in only a few cases; patients with syncope do not present specific clinical features.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:When are arrhythmias and conduction disturbances markers of myocardial ischemia at rest? 375

Cardiac receptors include both mechanically and chemically sensitive receptors located in atria and in ventricles. Atrial receptors innervated by myelinated vagal afferent fibers reflexly regulate heart rate and intravascular volume. On the other hand, stimulation of ventricular receptors can cause either reflex bradycardia and hypotension or, alternatively, excitation of the cardiovascular system. The former response is mediated by vagal afferents, whereas the latter is mediated by sympathetic (spinal) afferents. Under normal circumstances, cardiac receptors sense changes in wall motion or diastolic pressure and perhaps provide a fine tuning of the cardiovascular system. However, under certain pathological conditions such as coronary ischemia, which cause release of substances such as bradykinin and prostaglandins, there is an exaggerated response of the ventricular receptors. Because these receptors cause a reflex depression of the cardiovascular system and, in particular, induce renal vasodilation, they may protect the heart and kidney by lessening myocardial oxygen requirements and by increasing renal blood flow. In the situation of heart failure both atrial and ventricular receptors are reset and therefore provide for an exaggerated neurohumoral discharge. Finally, patients with aortic stenosis may demonstrate a paradoxical vasodilation and syncope during exercise when there likely is excessive stimulation of left ventricular receptors by the high transmural pressure.
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PMID:Cardiac receptors: their function in health and disease. 638 3

Although exercise-induced ventricular tachycardia (VT), whether sustained or nonsustained, is usually associated with significant organic heart disease, its prevalence, associated characteristics and prognostic significance in an asymptomatic, unreferred community-dwelling population are unknown. Therefore, the prevalence of VT associated with maximal treadmill exercise was assessed in 597 male and 325 female volunteers, aged 21 to 96 years (mean +/- standard deviation 54 +/- 16), from the Baltimore Longitudinal Study on Aging who were without apparent heart disease. Ten subjects, 7 men and 3 women, with exercise-induced VT were identified, representing 1.1% of those tested; only 1 was younger than 65 years. All episodes of VT were asymptomatic and nonsustained. In 9 of 10 subjects, VT developed at or near peak exercise. The longest run of VT was 6 beats; multiple runs of VT were present in 4 subjects. Two subjects had exercise-induced ST-segment depression, but subsequent exercise thallium scintigraphic results were negative in each. Compared with a group of age- and sex-matched control subjects, those with asymptomatic, nonsustained VT displayed no difference in exercise duration, maximal heart rate, or the prevalence of coronary risk factors or exercise-induced ischemia as measured by electrocardiography and thallium scintigraphy. Over a mean follow-up period of 2 years, no subject has developed symptoms of heart disease or experienced syncope or sudden death. Thus, exercise-induced VT in apparently healthy subjects occurs almost exclusively in the elderly, is limited to short, asymptomatic runs of 3 to 6 beats usually near peak exercise, and does not portend increased cardiovascular morbidity or mortality rates over a 2-year period of observation.
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PMID:Prevalence and prognosis of exercise-induced nonsustained ventricular tachycardia in apparently healthy volunteers. 648 25

A patient with an unusual "compulsion" to induce syncope over a period of years by bilateral compression of the carotid arteries subsequently had recurrent seizures. The EEG showed patterns typical of cerebral ischemia during the syncope and epileptogenic foci in both temporal lobes after sleep deprivation. It is difficult to distinguish between seizure and syncope associated with involuntary movements when making a differential diagnosis. We hypothesize that the frequent self-induced ischemic insult to the brain caused a cicatrix to develop, which in turn caused the frequent seizure disorder; and that because this ischemia functioned as a stimulus to the reward site in the limbic system, the patient repeatedly induced it.
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PMID:Repeated self-induced syncope and subsequent seizures. A case report. 663 12

The clinical manifestations of symptomatic coronary arterial spasm were analyzed in 30 patients whose coronary arteriograms demonstrated no fixed severe obstructions. The study group consisted of 14 men and 16 women (average age, 47 years). Angina at rest was invariable and it was usually typical in quality, location, duration and response to nitroglycerin. Exertional angina occurred in 23 percent and syncope with angina in 33 percent. Spontaneous remission of angina for at least 1 month occurred in 57 percent of patients. Prinzmetal's variant angina occurred in 77 percent of patients and only S-T segment depression or T wave changes during angina occurred in 23 percent. Major arrhythmias during ischemia developed in 47 percent. Exericse tests were positive in 24 percent. Myocardial infarction, probably due to coronary spasm, occurred in 7 percent of patients. Isosorbide dinitrate and propranolol were effective therapy in only 39 percent and 6 percent of patients, respectively. Nifedipine, a calcium flux antagonist, was effective in 80 percent of patients. Patients with normal coronary arteriograms who have clinical features suggestive of coronary arterial spasm should be considered for further investigation, including long-term electrocardiographic monitoring and provocative testing for spasm.
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PMID:Syndrome of symptomatic coronary arterial spasm with nearly normal coronary arteriograms. 698 57

Seven of 120 aneurysm patients admitted to the Henry Ford Hospital from October 1978 to August 1981 had giant internal carotid artery aneurysms that were treated by a combined internal carotid artery occlusion and extracranial-intracranial anastomosis. Three of these patients developed postoperative ischemic complications during the progressive closure of the carotid artery. These complications included the transient onset of syncope, hemiparesis, hemisensory deficits, and dysphasia. These complications resolved after the clamp was reopened and/or intravenous heparin was given. The possible mechanisms involved in the development of ischemia included the development of emboli at the occlusion site or inadequate flow originating from the area of the anastomosis. Prolonged occlusion of the vessel over a 7- to 10-day course with concurrent administration of intravenous heparin is recommended.
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PMID:Ischemic complications after combined internal carotid artery occlusion and extracranial-intracranial anastomosis. 709 8

Syncope with and without convulsion was studied in unselected blood donors in a community blood center. Convulsive syncope occurred in 0.03% of all blood donors and was more commonly observed when nursing personnel were alerted to its possible occurrence. It was more common in men. Although tonic extensor spasm was the most common convwithout convulsion was studied in unselected blood donors in a community blood center. Convulsive syncope occurred in 0.03% of all blood donors and was more commonly observed when nursing personnel were alerted to its possible occurrence. It was more common in men. Although tonic extensor spasm was the most common convwithout convulsion was studied in unselected blood donors in a community blood center. Convulsive syncope occurred in 0.03% of all blood donors and was more commonly observed when nursing personnel were alerted to its possible occurrence. It was more common in men. Although tonic extensor spasm was the most common convulsive movement, other complex convulsive phenomena occurred, some simulating epileptic seizure. No statistical difference in changes of pulse or blood pressure was found between subjects with convulsive versus nonconvulsive syncope. Similarly, no difference was found between subjects with tonic spasm and those with other convulsive phenomena, nor between those with "early" and those with "delayed" reactions. Marked individual variation may exist in the susceptibility of the central nervous system to ischemia. Some individuals appear to be predisposed to development of seizures in situations of global cerebral ischemia such as occur in hypotension and bradycardia.
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PMID:Convulsive syncope in blood donors. 710 29

Fifty-eight patients underwent unilateral vertebral arterial reconstructions over a 16-year period. Thirty-four underwent carotid operations as well. The first 18 patients underwent vertebral arterial reconstructions in conjunction with carotid endarterectomy as mandated in the Joint Study of Extracranial Arterial Occlusion as a Cause of Stoke. The next 40 underwent vertebral procedures for either brain stem symptoms alone, or for combined cerebral cortical and stem symptoms for specific indications after flow-obstructing carotid lesions had been corrected, but symptoms failed to subside. The surgical procedure consisted of subclavian-vertebral angioplasty except in one patient who underwent a subclavian distal-vertebral bypass graft to the level of the second cervical vertebral body. Syncopal episodes occurred as a major symptom in 16 and was controlled by either carotid and vertebral or vertebral artery operation alone except in four who also required cardiac pacemakers and one who needed correction of aortic stenosis. The long-term follow-up reveals that the stroke rate per average year for the first 14 years of follow-up was 1.2% per patient year with only five strokes having occurred in 410 patient years of follow-up and 70% of the patients having sustained no new neurologic episodes at the fourteenth year. Survival, however, was 45% at the fourteenth year with most deaths caused by myocardial infarction. The surgical procedure of vertebral angioplasty is indicated when bilateral vertebral arterial flow-obstructing lesions are found in patients with brain stem ischemia including drop attacks and syncopal episodes if flow-obstructing carotid lesions have been corrected and symptoms persist. The surgical procedure can be performed with a high degree of safety. The differential diagnosis of drop attacks and syncope in this age group should include, in addition to vertebrobasilar arterial insufficiency, transient cardiac arrhythmias, aortic stenosis, and convulsive disorders.
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PMID:Cervical vertebral angioplasty for brain stem ischemia. 730 36

Coronary revascularization has been suggested as sole therapy for secondary prevention of sudden cardiac arrest associated with ischemia. The use of implantable defibrillators (ICD) in combination with coronary revascularization for this patient population is unclear. Among 412 consecutive patients receiving an ICD, 23 (6%) were identified as sudden cardiac arrest survivors who were noninducible with programmed stimulation and had unstable angina or ischemia on a functional study; they underwent successful coronary revascularization. During a follow-up of 34 +/- 18 months, 10 (43%) of the 23 patients received ICD shocks (8 +/- 8 per patient, range 1 to 22 shocks), and nine of the 10 patients had syncope/presyncope associated with at least one ICD discharge. Patients with ICD discharges were compared with those without ICD discharges, and no clinical characteristics were statistically different between the two groups. In conclusion, revascularization alone may be inadequate therapy for survivors of sudden cardiac arrest associated with ischemia who are noninducible with programmed stimulation, and clinical variables cannot predict which patients are likely to have recurrent malignant ventricular arrhythmias.
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PMID:Incidence of implantable defibrillator discharges after coronary revascularization in survivors of ischemic sudden cardiac death. 763 7


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