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)

A cardiac pacemaker capable of responding to blood acidosis by change in its stimulation rate allows adjustment to a patient's metabolic needs. The blood pH is sensed by an iridium oxide electrode in the right atrium. During exercise, the venous pH decreases and the paced ventricular rate increases. If acidosis persists, the paced rate gradually returns to baseline and reaches it after about 70 minutes. A pH-triggered pacemaker has been implanted in a 72-year-old male. The pacemaker remained responsive one year after implant, increasing rate during exercise, cold pressor stress, ischemia of the arms and emotional stress.
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PMID:Preliminary experience with the pH-triggered pacemaker. 9 37

Platelets are believed to play a role in the pathogenesis of atherosclerosis and of the vascular obstruction that causes the acute complications of coronary artery disease. Since specific behavioral patterns appear to be related to the development of coronary artery disease and since emotional stress may predispose an individual to acute cardiovascular ischemia, it was hypothesized that platelet activation by catecholamines might be involved in these events. To study emotional stress, plasma samples were obtained from 61 senior medical residents immediately before they were to speak in public. There were significant increases in the plasma concentrations of the platelet-secreted proteins platelet factor 4 and beta-thromboglobulin and epinephrine and norepinephrine immediately before speaking, which demonstrates that platelet activation and secretion occur in association with this type of emotional stress. Four trials were carried out to study the mechanism for this observed platelet secretion: (1) phenoxybenzamine, (2) propranolol, (3) 650 mg aspirin, and (4) 80 mg aspirin were given several hours before the public speaking engagement. Neither phenoxybenzamine nor propranolol in doses that blocked the hemodynamic effects of alpha 1- and beta 1-adrenergic stimulation modified platelet secretion. Aspirin also did not block platelet secretion, which suggests that platelets were not being stimulated through a cyclooxygenase-dependent pathway. This study provides direct evidence of platelet secretion in vivo in association with emotional stress, and underscores the potential importance of platelet activation and secretion in the acute events that occur in patients with vascular disease.
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PMID:Platelet activation and secretion associated with emotional stress. 298 76

The primary pathophysiology of acute pancreatitis is due to a low flow state mediated through the neurohumoral mechanisms. Ischemia of the microcirculation, combined with hormonal and other biochemical factors, produces destruction of cellular elements of the pancreas. These changes can be triggered by one or more stressors, including the psychic factor. Emotional stress may not only be responsible for an initial attack of pancreatitis (idiopathic) but must be considered, like any other stressor, to be responsible for exacerbations, relapses or chronicity of pancreatic disease.
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PMID:Pathogenesis of pancreatitis: a unified concept. 369 76

The strong link demonstrated at autopsy between coronary atherosclerosis and angina pectoris led to the important concept that a fixed obstruction of 1 or more coronary arteries was the pathophysiologic cause of angina: myocardial ischemia and angina occurred when myocardial oxygen demand out-stripped the capacity of the diseased coronary artery to deliver oxygen. Therapeutic strategies were based on attempts to lower myocardial oxygen needs induced by physical and emotional stress. However, the finding that dynamic increases in coronary vascular resistance can also either precipitate ischemia or reduce the threshold of myocardial oxygen consumption (MVO2) at which it occurs has profoundly altered our understanding of the pathophysiologic features of angina and, therefore, its treatment. Dynamic coronary obstruction can occur at the large-vessel level, causing Prinzmetal's or variant angina. It is also possible that in some patients a continuum of large-vessel coronary vasoconstrictor tone exists, causing the common clinical situation manifested by angina with variable thresholds of onset. Recent studies have demonstrated that increases in the resistance offered to flow by small coronary arteries too small to be imaged by angiography can also decrease anginal threshold. The fact that ischemia can be precipitated by dynamic increases in large- or small-vessel coronary resistance has important implications for the therapy of angina pectoris. In those persons who mostly have a dynamic component contributing to their coronary obstruction, primary intervention with vasodilator therapy, including nitrates and calcium-channel blocking agents, are probably most effective therapeutically.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Dynamic coronary obstruction as a cause of angina pectoris: implications regarding therapy. 388 18

The clinical picture and investigation of 26 patients (16 males and 10 females) with diagnosis of transient global amnesia (TGA) are reported. Age ranged from 51 to 78 years at the time of TGA, which occurred mor often between 60 and 70 year-old people. Three patients presented more than one episode (3, 4 and 5). Precipitating factors were identified in 8 cases (emotional stress in 7 and physical exercise in 1). Risk factors for cerebrovascular disease were found in 13 cases, mainly hypertension (9 cases) and diabetes (3 cases). EEG was normal in 20 cases and disclosed diffuse delta waves in 2, temporal delta waves in 1 and temporal theta waves in another patient. CAT scan showed no abnormalities in 3 cases and ischemia in the vertebro-basilar system in another 2. Brain angiography was normal in 1 case and showed abnormalities in the vertebro-basilar system arteries in 3. During the follow-up period, which ranged from 1 to 84 months, no neurologic deterioration was seen. The role of risk factors for vascular diseases, epilepsy and migraine in the development of TGA is discussed.
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PMID:[Transient global amnesia: study of 26 cases]. 401 36

87 24-hour electrocardiographic monitoring sessions were conducted in 71 ambulatory patients (pts) in the early post-hospital phase after acute myocardial infarction. 29 (41%) had anterior, 42 (59%) inferoposterior myocardial infarction, 44 (62%) had angina or asymptomatic ischemia, 7 (10%) were in cardiac failure (II-III class NYHA). The occurrence of ventricular ectopic activity (VEA) during sleep hours was compared to the awake state; VEA during sexual and other activities of the awake state was studied. Excluding pts free of VEA during 24-hour monitoring the number of ventricular mature beats was lowered in 71% of sessions and augmented in 12% during sleep hours (p less than 0.001). Maximal grade of VEA was observed during wakefulness in 62% of session and in 9% during sleep (p less than 0.001); in 9% there was no difference, in 20% no VEA occurred. Total VEA, bi-tri-quadrigeminism and repetitive extrasystoles were significantly reduced during sleep: p less than 0.001, p less than 0.05 and p less than 0.01 respectively. This pattern was independent from site of infarction, presence of ischemia, cardiac failure (II-III class NYHA). A discrete correlation was observed between total VEA and heart rate; a poor correlation was seen between total VEA, multiform and repetitive extrasystoles. During wakefulness VEA was mainly related to physical exertion and emotional stress. Sleep and relax periods of the day showed VEA similar to sleeping hours of the night. Sexual activity did not significantly elicit more VEA than other activities of the awake state. Repetitive forms, observed in 8% of the population, were probably related to the rapid increase of sympathetic tone. The absence of repetitive VEA, potentially dangerous, during sleep hours (except the first) not due to antiarrhythmic drugs suggests to increase the dosage of these medications during the awake state in the majority of these pts.
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PMID:[Influence of sleep, wakefulness and some daily activities on ventricular ectopic activity in recent myocardial infarction (author's transl)]. 723 94

The development of ambulatory electrocardiographic recorders and analysers and the application of transesophageal echocardiography in the mid-1980's enabled investigators to quantify and describe the occurrence of silent as well as symptomatic ischemia in the perioperative period. Several technical advances which have recently occurred in ECG monitoring include the use of miniaturized digital computing equipment to store and analyze data. In addition, real time ST-segment analysis has become widely available on multicomponent monitors in both the operating room and intensive care units. The incidence of perioperative myocardial ischemia depends on the patient population, the surgical procedure, and the monitoring technique used. Several studies in the early 1990's have shown that cardiac morbidity in patients undergoing major, noncardiac surgery is best predicted by postoperative myocardial ischemia, rather than tradition preoperative clinical predictors. Long duration postoperative ischemia may be the factor most significantly associated with adverse cardiac outcome. Postoperative pain, physiological and emotional stress may all combine to cause tachycardia, hypertension, increase in cardiac output, and fluid shifts which, in high risk patients, might result in subendocardial ischemia and eventual myocardial infarction. If postoperative myocardial ischemia is the cause of late postoperative myocardial infarction in patients undergoing non-cardiac surgery, then treatment of postoperative myocardial ischemia should reduce morbidity. In addition, reducing pain and stress and avoiding postoperative hypoxemia might prevent postoperative myocardial ischemia and minimize the need for extensive preoperative cardiac evaluation.
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PMID:Myocardial ischemia--association with perioperative cardiac morbidity. 782 38

In anesthetised Wistar adult male rats, a model of circulatory brain ischemia was created. A behavioural difference as well as a difference in normal focal cerebral blood flow (CBF), were revealed between rats resistant against and predisposed to emotional stress. The mortality level was 10% in former rats and 27% in latter ones.
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PMID:[Prognostic behavioral criteria and the characteristics of the cerebral blood flow in rats with different sensitivities to emotional stress]. 858 Oct 51

There is uncertainty about the etiology of transient global amnesia and none of the pathogenetic hypotheses proposed so far, i.e. transient ischemia, epileptic discharge and spreading depression of cortical electrical activity, is completely satisfactory. Using water suppressed proton magnetic resonance spectroscopy we studied one patient during a typical episode of transient global amnesia and 2 weeks thereafter in order to investigate the metabolic changes in the hippocampal region. In both hippocampi, spectra of N-acetyl-aspartate, creatine-phosphocreatine, compounds containing choline and lactate failed to show changes consistent with cerebral ischemia, both in the acute phase and in the follow-up. Spreading depression in response to emotional stress seems a likely explanation in this patient, who suffered from migraine in the past.
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PMID:Proton magnetic resonance spectroscopy during transient global amnesia. 955 91

An analysis was performed of comprehensive (non-invasive and invasive) observations of IHD patients presenting with atherosclerotic lesions of coronary arteries of the heart and atypical clinical picture of the condition. A possibility was shown of a significant obstruction of arteries of the heart in atypical localization of pain and in those patients who had not derived much benefit from nitroglycerin during the development of ischemia and measures instituted against it. Inadequate reaction to nitroglycerin may be explained by specificities of changes in the vegetative nervous system, by the hemodynamics reaction, and, in the first place, by a propensity for developing tachycardia under physical loading, emotional stress, and after ingestion of nitroglycerin.
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PMID:[Sudden cardiac death: the possible role of latent myocardial ischemia in the mechanisms of its formation and development]. 1087 65


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