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)

Eleven patients with short P-R intervals and narrow QRS complexes had ventricular tachycardia due to organic heart disease: mitral valve prolapse with mitral insufficiency (2 patients); alcoholic (?) cardiomyopathy (2 patients); and coronary artery disease (7 patients). Intracardiac studies showed short A-H intervals during sinus rhythm in all cases. The onset of ventricular fibrillation (which, to our knowledge, has not been observed in patients having short P-R and A-H intervals coexisting with narrow QRS complexes) was documented in 4 cases. Only 1 patient (with quinidine syncope) had been premedicated. In the 3 other patients the episodes of ventricular fibrillation appeared during bouts of atrial fibrillation with rapid ventricular rates which could have been an exprerssion of the "enhanced A-V conduction" that had been manifested in sinus beats by short P-R and A-H intervals. In clinical settings and physiological conditions proven to be hemodynamically unstable (such as transient ischemia or acute myocardial infarction) these rapid ventricular rates could have led to ventricular fibrillation; directly because of the R-on-T phenomenon, and/or indirectly due to decreased coronary perfusion. Ventricular tachycardia and ventricular fibrillation due to organic heart disease probably occur more often than suggested by the few reported cases in the literature. Its significance, however, has to be clarified by further prospective studies.
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PMID:Ventricular tachycardia and ventricular fibrillation in patients with short P-R intervals and narrow QRS complexes. 9 18

Postmortem findings within the cardiac conduction system are described from the case of a black woman with sarcoid heart disease who died suddenly. Her clinical course had been characterized by recurring ventricular arrhythmias and bouts of syncope. Both the sinus node artery and the atrioventricular (A-V) node artery were sites of focal fibromuscular dysplasia, which thickened slightly the wall of the former but markedly narrowed the lumen of the latter. Small foci of sarcoid infiltration were present in the sinus node and the A-V node. Fatty replacement within the His bundle was attributable to the probable ischemia caused by narrowing of the A-V node artery. Sarcoid granulomata and infiltration with epithelioid cells were present throughout the ventricular myocardium, but were conspicuously less prevalent in the atria. All the large coronary arteries were normal. Many small coronary arteries in the ventricular myocardium were involved by the sarcoidosis and their lumen were narrowed. These findings and analogous ones reported by others are discussed relative to the pathogenesis of syncopal attacks and sudden death which seem to peculiarly prevalent in sarcoid heart disease.
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PMID:Clinicopathologic correlations. De subitaneis mortibus. XXV. Sarcoid heart disease. 87 28

In congestive heart failure, patients appear to have alimited ability to dilate their resistance vessels in skeletal muscle in response to a metabolic stimulus. This is true whether the metabolic stimulus is ischemia, dynamic, or static exercise. The mechanism for this limited arteriolar capacity is at least twofold; an increased sodium content of the vessels as well as an increased tissue pressure which is seen in edematous states. This can be considered a positive compensatory mechanism in that it helps to maintain systemic arterial pressure during exercise when the cardiac output fails to increase normally. If the resistance vessels were to dilate normally, then in the face of a limited cardiac output, exercise syncope would be expected to occur...
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PMID:Abnormalities in the regional circulations accompanying congestive heart failure. 110 32

In the elderly, a transient ischemic attack (TIA) and a hypersensitive carotid sinus reflex (HCSR) often co-exist and can pose a diagnostic challenge. Seven cases are presented. HCSR is a relative condition; besides increased irritability of the receptor or target organs, susceptibility of the nerve center to ischemia probably is induced by a slow heart rate or low blood pressure in any patient with pre-existing occlusive cerebrovascular disease. Dizziness and syncope of this type represent hemodynamic TIA in contrast to thromboembolic TIA. The carotid sinus massage test is recommended for differentiating the two types of TIA; the treatments differ. At present there is no uniform management that can be applied to either TIA or HCSR routinely. Therefore, treatment should be approached on an individual basis, keeping in mind the different pathophysiologic factors operating in the specific patient.
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PMID:The problem of dizziness and syncope in old age: transient ischemic attacks versus hypersensitive carotid sinus reflex. 124 91

Three hundred forty consecutive patients (mean age 69 +/- 9 years) were evaluated with adenosine tomographic thallium-201 scintigraphy for suspected coronary artery disease. Minor side effects occurred in 91% of patients. Out of 28 patients (8%) with potentially serious side effects, 28 had significant atrioventricular (AV) block (second-degree, 24 patients; third-degree, four patients; syncope occurred in two patients). Acute bronchospasm and severe refractory angina pectoris occurred in one patient each. All side effects were transient and without sequelae. One hundred twenty-one patients underwent coronary angiography within 9 days of adenosine thallium imaging. The predictive accuracies of adenosine thallium imaging for identifying and localizing ischemia to a specific coronary distribution were: left anterior descending = 88%, left circumflex = 84%, right coronary = 88%. The predictive accuracy of adenosine thallium imaging in patients with left bundle branch block was 91%, and was higher than the 71% predictive accuracy noted in 39 patients who underwent exercise thallium testing (p = 0.04). It is concluded that adenosine thallium-201 myocardial scintigraphy was (1) highly accurate for the detection and localization of significant coronary artery disease; (2) it was more accurate at detecting ischemia in patients with left bundle branch block than exercise thallium testing, and (3) subjective side effects were common and were of no diagnostic importance; transient AV block occurred occasionally.
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PMID:Safety and diagnostic accuracy of adenosine thallium-201 scintigraphy in patients unable to exercise and those with left bundle branch block. 151 88

In a prospective blinded trial, 24-hour continuous electrocardiographic monitoring for silent ischemia was used to try to identify rehabilitation patients at risk for cardiac complications. Five of 42 patients had episodes of silent ischemia, none of which occurred during physical therapy sessions. One of these patients had syncope while wearing the Holter; none of the other four patients had significant cardiac complications during their rehabilitation, and all were discharged home. None of the patients without ischemia on the monitor had complications, but two patients of 14 whose ECGs precluded monitoring for ischemia had complications. In addition, six patients had episodes of nonsustained asymptomatic ventricular tachycardia, 12 had episodes of supraventricular tachycardia, and four had significant ventricular ectopy, all without clinical significance. Despite the apparent high sensitivity and specificity of the technique, the positive predictive value of monitoring eligible patients for silent ischemia was 20%. We conclude that ambulatory electrocardiographic monitoring for silent ischemia or ectopy has limited clinical utility in the rehabilitation population.
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PMID:Silent ischemia in rehabilitation patients: limited clinical utility of electrocardiographic monitoring. 164 23

Cardiac arrhythmias may present in a variety of ways in the primary care setting. They may or may not be accompanied by related symptoms. Rhythm disturbances span the continuum of posing no risk to the patient to being life-threatening. The importance of a thorough history and physical examination to detect the presence of cardiovascular disease or related factors cannot be overemphasized. An ECG is essential for the accurate identification of cardiac arrhythmias. Evaluation and management of cardiac rhythm disturbances often requires collaboration with medical practitioners and possible specialist referral. The primary care nurse practitioner must be able to recognize the important red flags in clinical practice such as cardiac syncope, ischemia, or failure. Finally, an understanding of the diagnostic and therapeutic measures used for arrhythmia evaluation and management will facilitate appropriate patient education, counseling, and follow-up.
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PMID:A primary care approach to cardiac arrhythmias. 184 Sep 34

Heart muscle perfusion was studied by exertion scintigraphy Tal-201 in 24 patients, 16M and 8F, aged 16-45 years, means--28 +/- 7.4 years with hypertrophic cardiomyopathy. The relationship between perfusion disturbances and sudden death risk factors occurring in this group of patients was evaluated. Disturbances of heart muscle perfusion were found in 20 pts (83%); 2 pts had permanent perfusion defects, in 18 pts these defects were completely or partially reversible at rest. Only 4 pts (17%) had normal heart muscle perfusion. In patients with perfusion disturbances there was found a significantly more frequent occurrence of the following sudden death risk factors: 1. syncope (p less than .01) 2. ventricular arrhythmia of IV b class according to Lown (p less than .01) 3. advanced hypertrophy of intraventricular septum (p less than .01) 4. sudden death in patients families (p less than .05) The evaluation of the heart muscle perfusion confirmed the occurrence of myocardial ischemia in most of the examined patients. Normal coronaro-angiography in all the patients over 35 years as well as the young age of the other patients exclude atherosclerosis as the cause of myocardiac ischemia in the group under study. This is a confirmation of nonatherosclerotic etiology of myocardiac ischemia in hypertrophic cardiomyopathy patients. The correlation between perfusion disturbances and sudden death risk factors points to the role of ischemia in the natural course of disease and the value of exertion scintigraphy TI-201 in prognosing patients with hypertrophic cardiomyopathy.
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PMID:[Disturbances of myocardial perfusion by exertion scintigraphy in patients with hypertrophic cardiomyopathy and their relationship with sudden death risk factors]. 194 60

Left atrial ball thrombus is an infrequent clinical syndrome, which can have a catastrophic outcome but can be readily treated when recognized. It is usually a complication of long-standing rheumatic mitral stenosis. Symptomatic presentation is variable: fragmentation of the thrombus followed by peripheral embolization will produce ischemia or infarction of myocardium, brain, viscera, or extremities; random, intermittent, partial, or total occlusion of the mitral valve orifice may cause syncope, pulmonary congestion, and occasionally sudden death in other patients. Embolic and obstructive phenomena may also occur together. Cardiac physical findings usually suggest mitral stenosis; variability in the intensity of the diastolic rumble is common. Two-dimensional echocardiography is the gold standard for identifying ball thrombus. Cardiac catheterization provides assessment of coronary artery status when needed. The outcome of untreated ball thrombus is unlikely to be favorable. The results of anticoagulation and thrombolysis are unpredictable and potentially as harmful as no treatment at all. Current evidence although scant suggests that prompt surgical removal of the free thrombus, often in conjunction with mitral valve repair or replacement, is the appropriate therapeutic course in most patients.
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PMID:Left atrial ball thrombus: review of clinical and echocardiographic manifestations with suggestions for management. 203 92

The records of 483 patients admitted to the emergency room because of syncope were reviewed. Thirty seven patients (7.7%) were found to suffer from transient ischemic attack- (TIA) related syncope. This group is the subject of this report. Of these patients, 28 (76%) were men (mean age 71 years). Seven patients reported previous syncopal episodes. Past history revealed a high rate of ischemic heart disease (70%) and hypertension (68%). Concurrent neurologic symptoms, which led to the diagnosis of TIA-related syncope, included mainly vertebrobasilar symptoms: vertigo (in 55% of the patients), ataxia (46%), parasthesia (41%). Two patients most probably were presenting bilateral carotid artery disease. Various diagnostic tests (including electroencephalography, computed tomography, sonography, and cerebral angiography) were used to exclude other causes of syncope. During follow-up (mean 14.5 months) four patients (11%) had an additional episode of TIA and in three of them syncope reappeared. One patient had a complete stroke. We conclude that TIA is a much more frequent explanation for syncope than has been previously argued. These patients tend to be elderly males with high incidence of ischemic heart disease and hypertension. The concurrent neurologic symptoms, leading to the diagnosis, represent mainly vertebrobasilar territory ischemia.
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PMID:Transient ischemic attack-related syncope. 204 43


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